By Richard Holdener

Some call them life lessons, some call it experience, but the truth is we all make mistakes, We are, after all, only human. Some mistakes are less costly than others, like forgetting to tie your shoe. Others, like not looking both ways before you cross the street, can be considerably more so. The same goes for mistakes in the automotive kingdom. Forget to tighten a nut on your carburetor, and you might develop a small vacuum leak. Forget to tighten a rod cap, and you’re talking about a vacuum leak of epic proportions.

Somewhere between the two extremes are what we call necessary upgrades. Things that fall into this category include a valve spring upgrade required by a cam swap. The cam will make the power, but only if you have sufficient spring pressure and coil-bind clearance. The same goes for injectors and fuel pump, as the larger injectors will only work if they have sufficient fuel flow from the pump. The components in any performance motor are interrelated and work best when they work together.

One area often overlooked by enthusiasts is intercooling. By now, most of us know intercooling exists and that it is necessary, but sticking just any old intercooler on your supercharged performance motor isn’t going to optimize the combination. This is especially true when looking for big power. The problem comes from the notion that adding power is as easy as adding boost. You want more power? Just crank up the boost with a pulley change, right? Well, yes and no, as more boost can increase power, but higher boost levels also bring their own set of problems.

With boost comes higher temperatures, as inlet air temps increase in direct proportion to pressure (why we employ intercooling in the first place). The higher temperatures and flow rates that accompany pulley changes can tax your intercooler. Like the supercharger and nearly every other sub system on the motor, the intercooler was designed with a specific power level in mind. Kept in the designed range, the system works well, but exceeding the capacity of the system will cause problems, not the least of which is a reduction in power.

Before we get to the test, we need to understand that intercooling is a balancing act of sorts. The job of any intercooler is to counteract the increase in air temperature. To do this, airflow through the intercooler must do several things, including coming in contact with a cooling medium that is cooler than the inlet air itself. Since nature seeks stasis, heat will be drawn away from the air and into the cooling fins of the intercooler. Ambient air (or water) can then be used to remove the transferred heat from the core. The greater the surface area and length of time this transfer has to take place, the more effective the heat rejection will be.

The problem is that adding internal surface area restricts air flow, which causes an increase in boost before the core, but a drop in boost (and flow) after the core. Thus, a core design must balance the need for flow and cooling with the available size (fitment) constraints, to say nothing of cost. The take away for this is intercoolers should be sized properly for the given application, and one size here does not fit all.

To illustrate this fact, we set up a test with our Magnificent LS7 test motor. The 427 featured a GM LSX block from Gandrud Chevrolet stuffed to the gills with a Lunati crank, Carrillo rods, and CP Pistons. The power producers included TFS Gen X 260 LS7 heads, an MSD Atomic intake, and BTR Stage IV LS7 cam. Included in the build-up was an ATI 8-rib Super Damper, Moroso oiling system, and FAST 75-pound injectors.

The Magnificent LS7 was the perfect test mule for taxing the limits of the intercooled D1SC from Procharger. The idea was to run the D1SC first with the standard intercooler, then with the intercooler upgrade designed for the larger F1A supercharger. Both air-to-air units, the intercooler upgrade featured 4.40-inch thick core (3.1-inch for the standard) that allowed room for 3.5-inch inlet and outlets (3.0-inch for the standard core). For our test, the standard core was run with 3.0-inch intercooler tubing (supplied with the kit), which we upgraded to 3.5-inch tubing for the larger intercooler. The pulley size, air/fuel, and timing were all kept constant during the testing.

First up was the standard core. Run in anger on the dyno with the self-contained D1SC supercharger, the 427 LSX produced peak numbers of 944 hp at 6,600 rpm and 794 lb-ft of torque at 5,700 rpm. These were pretty impressive numbers given the fact that Procharger rated the D1SC at just 925 hp. Boost supplied to the motor (measured in the manifold) started at 3.5 psi and rose to a peak of 9.9 psi. We figured making 944 hp at just 9.9 psi was nothing short of magnificent, that is until we installed the new cooler.

After installation of the intercooler upgrade, things got serious. How serious? How does 1,003 hp and 864 lb-ft of torque sound? The extra flow offered by the larger core allowed more of that lovely boost into the motor, with a peak of 10.7 psi. This test clearly showed the importance of intercooler sizing and what happens when humans err with air.

A couple of things should be immediately evident from these power curves. First and foremost is the fact that adding the Procharger to the Magnificent LS7 LSX motor made for one powerful combination. Even with the smaller of the two intercoolers, the supercharged 427 exceeded 940 hp. The second obvious observation is the intercooler upgrade offered substantial power gains. Gains of this magnitude show the combination was nearing the flow limit of the smaller intercooler, making the upgrade a necessity. Installation of the larger intercooler core and plumbing increased the power output through the entire rev range, with the peak numbers jumping from 944 hp and 794 lb-ft of torque to 1,003 hp and 864 lb-ft.

Naturally, we data-logged the boost curves during the test. These curves represent the boost present in the manifold, as opposed to the boost present before the intercooler. Run with the smaller intercooler, boost from the D1SC started at 3.5 psi and rose to a peak of 9.9 psi. After installation of the larger intercooler (with no change in blower or crank pulley), the boost curve started at 4.2 psi and rose to 10.7 psi. The larger core offered less restriction and allowed more boost to the motor. The result was a sizable increase in power.

Sources: ATI, Atiracing.com; ARP, Arp-bolts.com; Brian Tooley Racing, Briantooleyracing.com; COMP Cams, compcams.com; CP Pistons/Carillo Rods, cp-carrillo.com; FAST, fuelairspark.com; Gandrud Chevrolet, parts@gandrud.com; Holley/Hooker/NOS, holley.com; Lunati, Lunatipower.com; Moroso, Moroso.com; MSD, Msdignition.com; Procharger, procharger.com; Speedmaster, Speedmaster79.com; Trick Flow Specialties, trickflow.com

It’s Go Time-Battle of the Blower Bumpsticks!

By Richard Holdener

Cam swaps for LS motors are always exciting because nothing wakes up an LS like wilder cam timing. We have seen 50, 60, and even 70 horsepower gains from a simple cam swap on an otherwise stock LS application. The gains have been even greater on modified motors. The reason for this is that LS motors already sport sufficient displacement, head and intake flow and lack only proper cam timing to make serious power. That doesn’t mean things like heads and intakes don’t make additional power, it just means that a cam swap should always be the first thing you think about when upgrading your LS. With that in mind, the question now becomes how well does a supercharged LS motor respond to a cam swap? Obviously, that is somewhat of a loaded question, as the outcome depends a great deal on which cam you choose, but the question still remains, do supercharged LS motors respond to blower-specific cam timing?

At the risk of killing the suspense, the simple answer to that question is yes, blower motors work best with blower-specific cam profiles. You can successfully run a supercharger with any of the stock LS cams, or any off-the-shelf normally aspirated cam, but a supercharged application (specifically a positive–displacement supercharged one), will benefit most from a cam profile designed specifically for that form of forced induction. One need only look at the factory LS offerings to see that GM saw fit to design not one but a pair of cam profiles specifically for the factory supercharged LSA and LS9 applications. Might the LS2, LS3 or LS6 cams work on these motors? Yes, just not as well. The LS9 cam profile was designed specifically for the 600+hp supercharged LS9 motor. Not only did the factory succeed with that motor, but the LS9 cam profile has become a go-to cam for many home-made supercharged LS combinations. Looking at the popularity and performance of the LS9, we set up a test to see if we could improve upon the factory offering. For this test, we pit the factory LS9 against a dedicated blower grind from the LS cam experts at Brian Tooley Racing (BTR).

As with most LS cam swaps, the test was a simple one. We ran the supercharged combination first with the LS9 then the Stage 1 cam from BTR. Before swapping cams, we needed to get our house in order with a supercharged test motor. Unfortunately we didn’t have a factory LS9 motor available, and, rather than attempting to duplicate the expensive factory offering, we put together something altogether different. Given the popularity, pricing, and availability of a 4.8L truck engine, we decided to run this test on a supercharged LR4. Prior to testing, we upgraded the beast with a set of JE forged pistons, CNC-ported TFS Gen X 205 heads, and ARP head studs. The head studs were used to secure the Fel-Pro MLS head gaskets, an important consideration given the boost and power level run during the cam test. Additional mods included 85-pound FAST (LS3) injectors, the Big Mouth, 102mm throttle body and a Holley Dominator EFI system. Of course the crowning glory was the 2.9L Whipple, twin-screw supercharger. Capable of supporting 1,000 hp, the intercooled, supercharged system was more than sufficient for our modified 4.8L. 

With our supercharged LR4 at the ready, we installed the LS9 cam and let the big dog eat. Run to a max of 6,700 rpm and tuned to perfection on 110-octane race fuel, the supercharged combo produced 675 hp at 6,700 rpm and 533 lb-ft of torque at 6,300 rpm. The proximity of the peak power and torque numbers is a strong indication that the power was still climbing at our self-imposed shut off point of 6,700 rpm (the graph confirms this). Run with the LS9 cam, boost from the Whipple supercharger started at 10.1 psi at 3,000 rpm then rose to a peak of 13.9 psi at 6,700 rpm. Satisfied with the repeatability of our results, we swapped in the Stage 1 cam from BTR. After minor adjustments to the fuel curve to match the air/fuel of the LS9 cam (no changes were made to timing), we were rewarded with peak numbers of 688 hp at 6,700 rpm and 546 lb-ft of torque at 6,300 rpm. The gain in power came with a slight drop in boost, down to a peak of 9.7 psi. The dedicated blower cam offered not just more power but less boost as well, a sure sign of a well-designed blower profile. We liked the gains offered by the dedicated blower cam, but it should be noted that the gains would be ever greater on an application with increased displacement and power.

Supercharged LS applications require very specific cam timing. GM recognized this when they designed the LS9 cam for the factory supercharged 6.2L. Typically the positive-displacement, supercharged cam profiles offer wide lobe separations and minimal (or negative) overlap. A couple side benefits of a blower grind is that it helps improve idle quality and enhance power production higher in the rev range (compared to a typical NA cam profile). Designed for larger displacement, supercharged applications, we couldn’t help but wonder how the factory LS9 cam worked on the smaller 4.8L, and if there were further improvements to be made over the factory offering. Compared to the stock LS9 cam, the Stage 1 cam profile from Brian Tooley Racing offered slightly more lift (+.048 in, +.024 ex), slightly more duration (+12 degrees in, +8 degrees ex) and a slightly tighter lsa (120 vs 122.5). The net result was an increase in power above 4,000 rpm to the tune of 15-16 hp. The cam swap also dropped the boost curve by .3 psi.

Sources

ATI;atiracing.com, Brian Tooley Racing;briantooleyracing.com, COMP Cams;compcams.com, FAST; fuelairspark.com, Holley/Hooker;holley.com, JE Pistons;jepistons.com, Lucas Oil;lucasoil.com, Trick Flow Specialties;trickflow.com, Whipple Superchargers;whipplesuperchargers.com

By Jeff Smith

It’s all about control. The automotive world is increasingly regulated by digital electronics, and hot rodders might as well take advantage of these amenities. If you look at the progression of new cars for the last 30 years, it’s all about digital management of every aspect of the automobile — including automatic transmissions.

This story will look at the evolution of the 4L60E, which is essentially a digitally controlled 700-R4. We’ve done the research so you don’t have to wade through all the inaccurate chaff to pick out the seeds of the best 4L60E. We’d also like to thank Jimmy Galante at Racetrans in Sun Valley, California, for his technical guidance with this story.

Let’s start with a brief history. The original 700-R4 was built in 1982 as a Corvette four-speed automatic with overdrive. This gearbox is different because it applies an overdrive to First gear to create Second. Third gear is 1:1, with overdrive again engaged to create Fourth.

This first version was designed with a bolt-on extension housing and employed a throttle-valve (TV) cable intended to signal engine load to the transmission via throttle position, instead of a using engine vacuum. Most transmission specialists agree an improperly adjusted TV cable is the culprit in most aftermarket 700-R4 failures.

In 1993, GM wisely converted to electronic control, eliminating the cumbersome TV cable while changing its nomenclature to 4L60E. The numbers decipher like this: 4 is the number of forward gears, L (longitudinal) for rear-wheel drive, 60 equates to a maximum 6,000 pounds of gross vehicle weight (GVW), and E for electronic control. Later transmissions were upgraded as 4L65 and 4L70 for use in heavy-duty trucks.

The 4L60E has now been in production for more than two decades and has experienced multiple performance updates that affect interchangeability. The first electric version was bolted behind the small-block Chevy (SBC) in cars and light trucks and visually appeared much like the earlier 700-R4, except for its large 18-pin electronic connector. The next major change was a six-bolt extension housing in 1993, compared to the original four-bolt.

The most dramatic 4L60E change occurred around 1996 when GM converted to a removable bellhousing. This move allowed adapting multiple engine bellhousing patterns to the same case. For torque converters, the earliest 700-R4 transmissions used a 27-spline converter. Later 1984-’97 700R4 and 4L60 versions were of the 298mm family line, with a 30-spline input and a 1.70-inch diameter hub.

With the introduction of the LS engine family in 1998, later 4L60E transmissions employed a third different input, also 30-spline, with a larger 300mm torque converter that is substantially thicker (about ¾-inch) than previous versions. There followed a fourth and most recent 4L60E evolution that accommodates an input shaft reluctor that does not effectively interchange with earlier converters.

Trans Swapping

Because LS engine swaps into older muscle cars has become a foundation in the performance world, this means the 4L60E is heavily ingrained in this parts dance. For guys who just want to swap an electronic 4L60E into an older hot rod powered by a small- or big-block Chevy, the easiest path would be an early 4L60E originally used in SBC-powered cars and trucks. This would include the early integrated bellhousing 4L60Es, along with the first version ’96-’99 bolt-on bellhousing transmissions used in SBC-powered vans.

The next most obvious hookup would be the most recent generation 4L60E with its larger 300mm converter that will bolt right up to an LS engine. In most cases, you can use the 4L60E trans with its 298mm style converter behind a normal, six-bolt LS crank flange engine (4.8L, 5.2L, 5.7L, 6.0L, and 6.2L). Truck engines such as the 4.8L, 5.3L, and 6.0L used a dished flexplate to place the starter ring gear in the correct position. The 298 and 300mm references are to converter diameter — 300mm equals 11.8 inches.

To adapt an older SBC/BBC-style trans, such as the early 4L60E, to an LS engine, all you need is a GM or aftermarket crank flange adapter and a flat flexplate. The adapter mounts between the crankshaft and the flexplate with the center portion of the hub protruding through the flexplate. This extends the short LS crank flange by 0.400-inch to the 1.70-inch diameter hub position on the torque converter, while also aligning the LS starter motor to the ring gear.

There is an exception to the above information. The 1999 and 2000 4.8L and 6.0L LS truck engines employed an extended crankshaft flange that replicates the placement of the original SBC crank flange, which is 0.400-inch closer to the converter than “normal” or flush LS cranks. In this case, the best option is to use a SBC-style 4L60E trans with a flat LS flexplate. Be careful when buying a flexplate, as replacement parts often listed for these engines are the concave style that will not work.

For those who desire to adapt a late model LS style 4L60E to a small-block Chevy, the best approach is to find a 4L60E transmission originally built for the small-block Chevy. This trans will have the bolt-on bellhousing with the traditional SBC/BBC bellhousing pattern.

Builders, however, are often faced with using what they have or can buy cheaply. Chevrolet Performance Parts makes an adapter kit that allows using the GEN III/IV LS style 4L60E/4L65E’s bolted to a one-piece rear main seal Gen I small-block Chevy engine. The kit (PN 19154766) includes an aluminum spacer (roughly 0.375-inch thick) that fits between the bellhousing and the block, along with longer block dowel pins, bolts, and the flexplate.

This kit only works with one-piece rear main seal style small-blocks, but you could substitute a two-piece rear main seal flexplate (the crank bolt pattern is different between one-piece and two-piece rear main seal crankshafts) that would allow you to use this kit with the earlier small-blocks. It would also be possible to build your own spacer. TCI Automotive offers longer dowel pins.

Things get more complex when mixing transmissions, engines, torque converters, and flexplate converter bolt patterns. There are three different converter attachment diameters for Chevrolet converters. The earliest and most common TH350 and TH400 torque converters used either a 10.75- or 11.5-inch bolt pattern that is measured from the crank centerline to the center of one bolt hole and multiplied by two. LS engine converters use an in-between 11.1-inch bolt pattern. Thankfully, the 11.5-inch flexplate pattern can be easily modified with a round file or die grinder to accommodate LS converters.

For those wanting to swap a 4L60E into an earlier car, you also need to think about speedometers. There are several companies, such as ShiftWorks, that offer a cast aluminum tailshaft housing that will drive the original speedometer cable. This will cost between $500 and $600. Many of the stand-alone controllers will indicate speed, but this requires using their display.

Another option is to use the 4L60E’s stock VSS (vehicle speed sensor) signal to drive an electronic speedometer available from several companies, like AutoMeter, Classic Instruments, SpeedHut, and others. Or, you could use an electronic speedometer and drive it with a GPS signal. A different alternative comes from companies like Abbott or Speedhut who offer a conversion box that uses the VSS signal to command an electric motor that drives the stock cable speedometer. SpeedHut’s version is about to come online, and we are told the cost should be around $400.

As you can see, there are multiple variations on the 4L60E transmissions that make it very easy to wander down the wrong performance path. Mistakes are easy, especially if you are mixing and matching engines and transmissions. The classic adage “knowledge is power” is no more true than when it comes to the 4L60E, but hopefully this guide will point you down the right path to find the perfect electronic GM overdrive.

Trans Length Chart

This TCI chart calls out the different 4L60E transmissions and their lengths compared to a typical TH350. The bellhousing pattern refers to either small-block Chevy (SBC) or LS Gen III/IV engines.

Trans Tips

You can quickly identify later 4L60E versions by the RPO code cast into both sides of the case. It’s best to use more than one means to identify a specific transmission to avoid possible individual year idiosyncrasies.

*Weight with fluid, minus torque converter.

Parts List

Sources: Abbott Enterprises;abbott-tach.com, Auto Meter Products;autometer.com, B&M Performance Products;bmracing.com, Chevrolet Performance;chevrolet.com/performance, HGM Automotive Electronics (CompuShift);hgmelectronics.com, Painless Wiring;painlessperformance.com, Powertrain Control Solutions;powertraincontrolsolutions.com, Speedhut;speedhut.com, TCI;tciauto.com

Words And Photos by Richard Holdener

Diehard Dodge guys might argue the fact, but the modern Hemi and (GM’s) LS have at least one important design criteria in common. Chevy guys will note that engineers stepped way up in the head flow department when they designed the LS family, especially the later (rec-port) LS3 motors. Not to be out done, the Dodge boys blessed their beasts with not only a ton of technology (Multiple Displacement Systems (MDS), Variable Camshaft Timing (VCT) or Active Intake systems, but impressive head gear as well. Like GM, the Hemi motors combine mild cam timing with impressive head flow to produce amazing power. Toss in the fact that only one manufacturer can claim ownership to the legendary Hemi name-and you start to see why the Dodge boys would rather fight than switch.

The head flow offered by the modern Hemi motors is important as it all but dictates how well the motor responds to other performance modifications, most notably cam timing. Right from the factory, the Hemi motors (5.7L, 6.1L and 6.4L) were blessed with impressive cylinder heads. In stock trim, the intake ports on the 5.7L heads top 260 cfm. That is enough airflow to support over 525 hp on a modified (normally aspirated) Hemi application. The larger 6.1L (and 6.4L) heads flow even more, but the icing on the cake is that all heads will respond to porting. We’ve seen ported Hemi heads post flow numbers topping 370 cfm. Why all the talk about head flow on a cam test? Since the Hemi motor already offered adequate displacement, compression and head flow, all it needed was more aggressive cam timing to show some serious gains. Basically you have a motor that has everything BUT a performance cam. When you add the right cam to a Hemi, you end up looking like a hero.

We recognized that the power gains would be greater on a 6.1L or 6.4L, but we decided to run this test on the more common (and now affordable) 5.7L Hemi. Before swapping cams, we had to select a suitable test motor. The after market is full of various crate and performance Hemis, but we decided to go the low-buck route and snag one from a local wrecking yard. Hemis were available in a variety of different applications, but our 5.7L test motor came from the engine bay of a 2006 Dodge Ram truck.

Like GM, Dodge trucks handily out sold their Hemi-powered performance cars, so look for a truck motor when searching for a project power plant. As delivered from the salvage yard, our 5.7L Hemi test motor came complete with wiring harness, sensors and full accessories (essentially a complete take-out motor) for $1,700. Compared to the popular 5.3L LS truck motor most commonly used by GM enthusiasts, the 5.7L Hemi offered both increased displacement and power. Let’s not forget the 5.7L was also sporting one of the most famous names in the industry!

Before running the Hemi on the dyno and performing a cam swap, we replaced the factory valve springs with 26918 springs from the COMP Cams catalog and filled the crankcase with Lucas 5W-30 synthetic oil. The motor was tuned using a FAST XFI management system and run through a set of STR8 exhaust manifolds. Run in otherwise stock trim, the 5.7L Hemi produced 385 hp at 5,500 rpm and 421 lb-ft of torque at 4,300 rpm. Illustrating that the Hemis know how to produce more than just peak horsepower was the fact that torque production from the 5.7L exceeded 375 lb-ft from 3,300 rpm to 5,300 rpm.

Though COMP offered a number of milder grinds for the Hemi, we stepped up to the XFI 273H-14. A healthy grind to be sure, the hydraulic roller cam offered a .547/.550 lift split, a 224/228-degree duration split and 114-degree lsa. We plan on installing ported heads at a later date and wanted a cam to work with our future upgrades. Equipped with the 273 cam, the 5.7L Hemi produced 449 hp coming at 6,100 rpm and 443 lb-ft of torque at 4,500 rpm. The cam swap increased the peak power output from 383 hp to 448 hp, a gain of 65 hp, but out at 6,300 rpm, the Hemi Helper offered an additional 100 hp!

Power Numbers: Stock vs COMP 273H-13 Cam

Power Numbers

Run in stock trim with the spring upgrade and SRT8 exhaust manifolds, the stock Hemi produced 385 hp and 421 lb-ft of torque. That the Hemi produced more torque than horsepower was a sure indication of the mild cam timing, especially given the impressive head flow. Hardly a race cam, the 273H-13 offered impressive power gains. Swapping the cam netted an increase of 65 horsepower (peak to peak) and an additional 100 horsepower at 6,300 rpm. For stock motors looking for a sizable torque gains while maintaining idle quality, check out the smaller 260H-13 cam, but we plan on stepping up to ported heads and even a stroker short block, so we opted for the more aggressive 273H-13.

Sources

COMP Cams
compcams.com

By Jeff Smith

Big displacement engines like this 520ci Jon Kaase Boss 9 engine make building a car that accelerates briskly very easy. Even in a heavy car with an automatic will be a thrill with an engine that can make over 900 horsepower with an astonishing 700 lb-ft of torque way down in the rpm curve.

In the performance game, the talk is all about horsepower. It’s splashed across magazine covers and horsepower numbers are prominently displayed especially now when the numbers are over 1,000. It seems that we are forever being indoctrinated into believing the horsepower is the great solution. And most of the time, that’s correct. But not always. If you are building a Bonneville car or a top speed race car, then peak horsepower is a very powerful thing. But for a drag race car or even a mild street car – a big peak horsepower number is not always the best solution if you’re trying to build a car that’s quick. When we say quick, let’s define the term. In the early days of drag racing, the winner was always the guy who got there first, but they identified the strength of the run based on trap speed. In top speed racing, you are given a long run like five to seven miles to achieve terminal velocity. But in modern drag racing – you only have a quarter and sometimes only an 1/8-mile – 660 feet – to take the stripe. A quick car is one that will get there in the shortest amount of time – and that’s what we’ll dissect in this story.

We might want to define the terms we’re working with here just so there’s no confusion. Internal combustion engines are rated using two different types of power – torque and horsepower. These ratings are directly related yet different. Basically, torque is a measurement of a twisting motion – like that generated by the output of an engine’s crankshaft. This torque is expressed in pound-feet (lb-ft) so that one lb-ft is the force required to twist a shaft with one pound of effort over a one-foot radius. What this measurement doesn’t describe is the amount of time required to perform this effort. Once we introduce time into the equation, then we can define that amount of effort (torque) over a given amount of time – which in an internal combustion engine’s case is expressed in revolutions per minute (rpm). This amount of work was given the term horsepower by James Watt back in the 1700’s to compare the amount of work his improved steam engine could produce compared to the amount of work performed by a typical draft horse, which was something his customers were intimately related.

The equation that Watt created has been simplified to: Torque x RPM / 5,252 = HP

To give this an example, let’s say our engine makes 300 lb-ft of torque. At 3,000 rpm this means the engine is only making 171 horsepower (300 x 3,000 / 5,252 = 171). However, if we add performance parts to our engine and spin it a little faster, it is capable of making that same 300 lb-ft of torque at 6,000 rpm. By doubling the rpm at which the engine can make power – we now have a more powerful engine making 342 or twice the horsepower. The reason for this doubling of horsepower is that the engine is making the same torque in exactly half the time of the first engine – 6,000 instead of 3,000 rpm. Given the choice, most hot rodders would choose the more powerful engine. But in the performance world, things get a bit more complicated.

The reason that large displacement engines are so popular with performance enthusiasts is that as displacement increases, so does the ability for the engine to make more torque at lower engine speeds. Which is why hot rodders love big engines. A typical performance V8 engine can make 1.2 to 1.25 lb-ft of torque per cubic inch of displacement. For a 300ci engine, 300 x 1.25 = 375 lb-ft of torque, which for a pump gas street engine is a decent torque number. But now let’s apply that same 1.25 lb-ft per cubic inch plan to a 520ci big-block Ford and suddenly the numbers become a bit more Kong-like: 520 x 1.25 = 650 lb-ft of torque. This is no secret and also just puts numbers to what hot rodders have known for years – big engines make big torque.

Torque is what really moves the car, but it gets lost in the bench racing sessions when everybody only wants to talk about horsepower. But let’s go back a bit and look at engines like the Buick and Pontiac 455 ci engines. They made great torque but because of their limited cylinder head size and greater internal friction from long strokes, these larger displacement engines were not as efficient in terms of horsepower per cubic inch. There are exceptions of course, like 500ci NHRA Pro Stock engines that spin to 10,000-plus rpm and make upwards of 1,400 horsepower. At 2.8 hp/ci, these normally aspirated monsters are exceptional, but also somewhat peaky, engines. What this means is that race engines like these tend to have relatively narrow power bands where all the power is concentrated in a range of 1,000 to 1,200 rpm. We’ll define this power band as the rpm spread between peak torque and peak horsepower. A common problem with race engines is that escalating horsepower and rpm are accompanied by an increasingly narrow rpm range where the engine really makes its power.

This also occurs with street engines. Making power with any internal combustion engine is a compromise between torque and horsepower. The search for additional horsepower for a normally aspirated engine follows the path of the horsepower equation. The equation tells us that if you make the same amount of torque at a higher engine speed, you will make more horsepower. For most engines, in order to make more peak power, a longer duration cam will push the peak torque point higher in the rpm curve. Combine that longer duration with larger intake and exhaust port cylinder heads, a short runner length intake manifold, and large tube headers and you have the makings of an engine that can deliver serious horsepower. But all these components also contribute to shifting the engine’s power band to a higher engine speed. A common power band spread will be 1,500 to 1,700 rpm. In some exceptional cases, this can expand to as much as 2,000 rpm, but that’s rare. In the quest for more normally aspirated power, longer cam duration and bigger heads generally narrow the power band to 1,000 rpm and the longer duration pushes the horsepower peak to much a higher engine speeds. In order to take advantage of the higher rpm power, this most often is solved by adding a deeper (numerically higher) rear end gear.

Street-driven cars usually don’t have the luxury of running a 4.56:1 or 4.88:1 gear ratio. Narrowing the power band also places greater attention on maintaining the engine speed within this limited area. This is where additional gears in the transmission really help. So in the case of a Competition Eliminator car powered by a high horsepower engine with a narrow power band, this could call for a five-speed manual transmission instead of a four speed. The additional gear reduces the rpm drop between gears which will maintain the engine within its power band with the result being the car is now a tenth or perhaps two-tenths quicker. Even the OE’s have picked up on this effect. Note that as engines become smaller, with higher specific output, they generate less torque. To make up for this lack of torque, the OE’s have been adding more and more gear ratios to their transmissions. Chrysler, for example, currently has an eight-speed automatic transmission. The reasoning behind this increase in ratios is to maintain the rpm within a given rpm range where the engine makes power.

The difficulty with street-driven cars is that they are often compromised by the demand for more street-oriented rear gear ratios and limited to three- or four-speed automatic transmissions. An overdrive transmission can help by allowing the use of a deeper rear gear to help acceleration, but the overall limitations still apply. This brings us back to the question that every performance enthusiast needs to investigate if he is interested in improving acceleration. We’ll use the drag strip as our evaluation criterion for power improvements and what you’ll discover might change the way you think about adding power and where you should place your efforts so that it will do the most good.

Let’s use an example to illustrate the point. We put a 355ci small-block Chevy on the dyno and compared the power produced by a single plane versus a dual plane intake manifold. We equipped our engine with a classic combination of a set of Edelbrock aluminum heads combined with a mild COMP Cams hydraulic flat tappet 268 Xtreme Energy camshaft with 224/230 degrees of duration and 0.477/0.480-inch valve lift with a 110-degree lobe separation angle. Along with a set of headers and a 750 cfm Holley carburetor, this engine could be considered the prototypical street small-block. The two intakes we tested were the Edelbrock Performer RPM dual plane compared against the Edelbrock Victor, Jr single plane.

Besides the usual e.t. and speed results, the Quarter, Pro program also includes an interesting option called an RPM histogram. This chart reveals the amount of time the engine spends at various rpm points. This chart reveals very valuable information. For example, according to this graph this engine spends much of its time between 4,600 and 5,600 rpm. Armed with that information, it would seem like a good idea to concentrate on improvements in that rpm area because the power will deliver the greatest benefit.

We ran both intake manifolds across this engine and recorded the torque and horsepower curves. Many engine guys will naturally look at the horsepower peaks and quickly make a judgment based on the higher horsepower number. In this case, the Victor, Jr. intake was worth 401 peak horsepower versus 398 for the dual plane. But when we plot both torque and horsepower curves on a graph, it becomes obvious very quickly that while the Victor, Jr. did out-horsepower the Performer RPM, the dual plane was clearly better at making torque – especially between 3,000 and 4,900 rpm. In this range, the dual plane made as much as 39 lb-ft of torque more than the single plane intake. That’s a huge gain in torque and something you would certainly feel in the seat of your pants when the throttle is planted firmly to the floor.

This graph and chart plot the power comparison of our small-block Chevy dual plane vs the single plane intake. Note the major torque improvements of the dual plane over the single plane below 5,000 rpm. For a mild street car, it’s clear that the dual plane is the better choice even though it loses as much as 22 hp to the single plane at the top.

We plugged these two power curves into the Quarter, Pro drag strip simulation program. This program was originally designed by Patrick Hale and it has become our favorite drag strip simulation program. Once we added the two different power curves into the program, it was easy to compare the differences in the projected acceleration rates. By now you’ve probably already figured out that the dual plane’s torque curve delivered much stronger acceleration. While the dual plane was worth as much as 39 lb-ft, the overall average was closer to 19 lb-ft of torque but that was enough to push our simulated Chevelle to run 0.15-second quicker and 1.4 mph faster. The numbers came out to a 12.33 at 108.80 for the single plane intake while the dual plane was quicker with a 12.18 at 110.20 mph.

The reason for the dual plane’s quicker elapsed time is its superior average torque. However, the reason for the quicker quarter-mile e.t. has as much to do with our test car as it does with the engine’s additional torque. This is an important point that is often lost when doing comparisons. In this case, we are using a relatively heavy 3,600- pound Chevelle with a three-speed automatic, a conservative 3.31:1 rear gear ratio, and a tight torque converter. If we were to plug these same comparisons into a lighter and smaller ’32 Ford coupe with a four-speed manual trans, deeper 4.10:1 gears, and big tires, the added torque from the dual plane would still be quicker, but the differential would not be as great. Let’s look at why this is.

We chose to make the ’32 Ford to weigh only 2,800 pounds, which will instantly improve acceleration but the real reason that the improvement wasn’t as great is because we changed the transmission. This has less to do with the type of transmission – converting from an automatic to a manual – and more to do with the reduced gear spread. By adding another gear (from three speeds to four), this reduced the rpm drop between gears, which narrows the engine’s operating rpm after it is launched. The Quarter simulation program gives us the rpm drops with each gear changed. Rather than go through all the numbers, let’s look at average rpm drop.

For the automatic, the average drop in rpm (using TH400 transmission ratios) was 2,140 rpm. Using a TR-6060 manual transmission (only the first four gears) this delivered an average rpm drop of only 1,630 rpm. The reduced rpm drop delivered by the manual trans keeps the average rpm 510 rpm higher at the completion of the shift. By nature, this will increase the average time spend at higher engine speeds. This tends to help the engine with more power at the higher engine speeds. But our simulation shows that leaving at around 3,000 rpm, the engine with the higher average torque in the middle still accelerates quicker.

As you can see with these examples, average torque is a much better way to evaluate an engine’s performance than just using peak horsepower. As we’ve mentioned earlier, these examples are all aimed at a typical street car – not a dedicated drag car. In the case of a dedicated drag car, the power band will tend to dictate the type of transmission used. So with a narrow power band, a manual trans with more gears is a good idea. In the case of a class legal car where a two-speed automatic transmission (like a Powerglide) is required by the rules, this would dictate building an engine with a wider power band in order to compensate for that huge rpm drop. Actually, from what we hear, some Powerglide racers use a very loose converter to keep the engine speed high even after the shift.

To condense this down to its logical conclusion, if performance and acceleration are the primary goal, then the street car builder has essentially three approaches. The first is to build the drivetrain around the engine’s power curve to optimize performance. The second is to build the engine to take advantage of the car’s existing drivetrain. The third option is where most projects exist – they optimize the engine as best as possible within the limitations of the current drivetrain. From this starting point, the builder can begin to approach the way the car needs to be constructed. If your plans call for a heavy car with an automatic transmission and a relatively tight torque converter, the ideal engine would be a large displacement engine or a possibly a small-block with a positive displacement supercharger than will make lots of low-speed torque. Or, if you really want to build a high-winding, small displacement engine that will spin to 7,500 rpm, an engine like that would be best served in a lightweight body style or perhaps a street rod equipped with a manual transmission – preferably with a deep rear gear ratio to keep the engine in the rpm range where it can make its power. Another example for that high rpm small-block might be open road race top speed car where you can choose a rear axle gear ratio and tire size that will put the peak horsepower rpm at or near the vehicle’s top speed potential.

Gear Ratios

The following is a comparison of the Chrysler 8-speed automatic versus the old school three-speed 727 Torqueflite. We list the ratios as well as the percentage of rpm drop between shifts. As the number of ratios increase, the rpm drop between gears decreases, maintaining the engine speed within a narrower power band. The additional gears also allow a much deeper First gear as evidenced by the 4.71:1 First gear in the eight-speed. Also note how Third gear in the eight-speed is nearly the same ratio as First gear in the 727.

The opposite effect is what many drag cars with very high torque and horsepower engines are using. For example, the Rossler TH-210 refers to a 2.10:1 First gear ratio in a TH-400 transmission that reduces the amount of torque multiplication over the tires. With a 2,500 horsepower engine, you don’t want to multiply the torque yet you still need a decent gear ratio to help launch the car. Second gear is around 1.30:1 which splits the difference between First and Third gear. This is still better than using a Powerglide with its large rpm drop between First and High gears.

Conclusion

None of the material presented here is shockingly new. But sometimes the proper approach can get lost in a world of hype and hyperbole. Building an engine with lots of peak horsepower will always be something to use as a goal, just don’t forget about the torque that gets you there in the first place.

Class legal cars like the SAM Racing 2012 (updated to 2014 body specs) runs a CC/Stock Automatic class legal LS7-based 427 with an A-1 TH3350 trans and converter. The Camaro, driven by Brian Massingill, has run a best of 9.14 at 145 mph and it gets there on a very strong torque curve combined with excellent peak horsepower – none of which the SAM folks are willing to divulge!

By Jeff Smith

There’s no denying that the new GM LS, Chrysler Gen III hemi, and Ford Mod motors have carved a healthy niche in the pantheon of performance engines. While the power is there for the making and taking, these new engines also demand new ways of accomplishing standard practices. For example, how do you pressure-lube one of these new-gen engines when the oil pump is driven off the crankshaft?

Let’s say you’ve just bought a brand new LS3 or perhaps a new Mopar 6.1L hemi crate engine. Accepted engine protocol demands that any new or long-dormant engine be treated to fresh, pressurized oil pushed through all bearings and wear surfaces before the engine fires for the first time.

The problem is today’s modern engines don’t use a distributor and the oil pump is driven directly off the crank so there’s no way to externally spin the oil pump. A classic internet forum remedy is to “Yank and Crank”. This means pulling the spark plugs and cranking the engine with the starter motor and hoping the oil pump will pressurize the engine. The problem is that the pickup in the oil pan is a long distance from the crank-mounted oil pump. The starter motor’s cranking speed is often too slow to prime the pump so no oil pressure is created. Plus, spinning a new engine with dry main and rod bearings is exactly what you don’t want to do if you prefer to treat your engine with respect.

One solution is a sealed, external oil reservoir connected to the engine using 15 to 20 psi air pressure to push the oil into the engine. While this idea works, especially if you pre-fill the oil filter first, this pushes oil generally through just the main and rod bearings. The limited volume and pressure will not push oil all the way up to all 16 rocker arms, which is the best indication that the entire engine has received oil.

Our plan called for a cheap but reusable oil reservoir large enough to carry 5 to 7 quarts of oil and would mount a used oil pump that could be driven by an electric drill motor. We also wanted to recirculate this oil through the engine, so we drilled out a bolt that matched the drain plug threads to install a -6 return line fitting connected on the other end to a -6 AN bulkhead fitting bolted to the lid of the reservoir. This allows us to run the drill motor continuously which is important because it can take 5 to perhaps 10 minutes to push enough oil through the engine to eventually lube all 16 rocker arms. We also rotate the crankshaft roughly 90 degrees at a time to ensure oil gets to all 16 rockers.

This simple, inexpensive pressure luber can be universally applied to any modern engine. While there are several different ways to approach this project, we like this idea because it is inexpensive and uses parts that are generally easy to obtain. Our parts list is comprised of a simple hardware store plastic bucket, a used small-block Chevy oil pump, a few AN fittings, and a couple lengths of hose. The only exotic tool required is a ½-inch electric drill motor. We’ve used our homemade luber on multiple LS engines and it gets the job done quickly and efficiently. Once the task is accomplished, we connect the pressure and return lines with a T fitting and wrap the bucket in a large plastic bag to keep the dust out until it’s ready for the next engine. Generally after pressure lubing two or three used engines, we dump the oil as it begins to get dirty.

Check out our plan and while our photos show it used on an LS engine. This will work equally well on Ford Mod motors and Chrysler hemi engines. If you’re creative and a good scrounger, you can probably build one for $60 and that price is based on all new hoses and AN fittings. Build one for yourself and we guarantee you’ll be popular with your friends who own late-model engines.

Parts List

Sources

COMP Cams
compcams.com

Holley Performance Products (Earl’s)
holley.com

By Richard Holdener

If you haven’t already checked out the two-part series we did on the junkyard 351 Windsor Ford, shame on you, because it was cool stuff. We pulled a 5.8L EFI motor from the engine bay of a full size F-150, slapped it right on the dyno, and were rewarded with roughly 250 hp. While that seems like a small number for a V8, especially one sporting over 350c.i., such was the state of affairs back in 1995 truck land.

Knowing there was more to be had, we replaced the stock heads, cam, and intake with a top-end kit (pt#2090) from Edelbrock. The kit included a healthy hydraulic roller cam (.573/.582 lift split, a 235/239-degree duration split and 112-degree lsa), a set of E-CNC 185 heads and Performer RPM Air Gap intake. Run in carbureted trim with a 750 Holley, the power output of the top-end equipped 351W jumped to more than 450 hp. This was reduced slightly (to 433 hp) in part 2 when we replaced the carburetion with an EFI RPM II upper and lower intake. After running EFI on the 351W, we started wondering what it might take to top our top-end kit?

In case you haven’t figured it out, the answer is boost. In fact, the answer to any performance question is always boost, and if a little boost is good, more must be even better, right? To illustrate just how good boost is, we decided to top the 351W with an efficient Vortech supercharger.

Given the impressive maximum specs of 1,150 cfm, 22 psi and 750 hp (a conservative rating by Vortech by the way), it is not surprising we chose the Vortech V3 SI trim for our Windsor. We had no intention of reaching, let alone surpassing the maximum power level listed by Vortech, but we liked the fact the SI V3 offered such a high adiabatic efficiency rating (translation: lower charge temps under boost).

Though we planned on keeping boost to a minimum on our non-intercooled combination, we did want to maximize the power output at those lower boost levels. We also liked the fact the V3 featured self-contained oiling, thus eliminating the need to supply oil to the blower or punch a hole in the pan. Yes, the Vortech V3 offered an impressive combination of power potential, reliability, and ease of installation.

We installed the Vortech V3 onto the awaiting Windsor using a 3.625-inch blower pulley. This was teamed with the supplied 6-inch crank pulley, which produced a maximum boost pressure of 5.9 psi at our peak engine speed of 6,000 rpm. Quick math told us that using the 3.625-inch blower pulley and 6-inch crank pulley combined to produce a drive ratio 1.655:1 (6.0/3.625).

When we factored in (multiplied) the internal step ratio (gearing inside the blower) of 3.6:1 and a maximum engine speed of 6,000 rpm, we got a maximum impeller speed of 35,751 rpm. This was obviously well under the maximum of 52,000 rpm listed by Vortech, so we knew there is much more power to be had from the V3. We purposely started out on the safe (low-boost) side of the equation. Equipped with the Vortech producing just under 6 psi, the supercharged 351W produced 559 hp at 6,000 rpm and 518 lb-ft of torque at 4,800 rpm. Running under 6 psi, the Vortech improved the power output of the 5.8L Ford by more than 125 hp!

As impressed as we were with the results of the supercharged combination, we couldn’t help but smile knowing there was much more to be had, and how easy it was to unleash it.

The great thing about supercharging is more power is never more than a pulley swap away. Do you want more power? Just add more boost. Of course, there is a limit to the fun, but we were nowhere near that limit on our low-boost Windsor. So, we swapped out the 6.25-inch blower pulley for a smaller 3-inch pulley. This increased the impeller speed to 43,200 rpm, a jump of almost 7,500 rpm. This increase in blower speed pushed the peak boost pressure up to 10.5 psi and the power right along with it. Run at 10.5 psi, the Vortech 351W produced 645 hp at 6,100 rpm and 584 lb-ft at 5,100 rpm.

It bears mentioning that you should consider intercooling at this elevated boost level, and Vortech offers systems designed to help lower the charge temps (especially important on pump gas).

We loved how the Edelbrock top-end kit increased the power output of the 351W by more than 180 hp, then loved it even more when the Vortech topped the top-end kit by 213 hp. The question now is, how do we top this?

The stock 5.8L EFI Ford (351 Windsor) was upgraded with an Edelbrock top-end kit that included a healthy hydraulic roller cam, E-CNC 185 heads, and the RPM II EFI intake. Run in normally aspirated trim, the modified 351 produced 433 hp and 430 lb-ft of torque. After topping the top-end kit with a Vortech V3 supercharger, the power output jumped to 559 hp and 518 lb-ft of torque at a peak of 5.9 psi. As much as we liked adding more than 125 hp to our 351W, we knew there was more to be had. Stepping down from a 3.625-inch to a 3.0-inch blower pulley increased both boost and power. Running a maximum of 10.5 psi resulted in 645 hp and 584 lb-ft of torque.

RELATED: Topped Off: Edelbrock 351W Power Packages

RELATED: We Like RPM II: Edelbrock EFI Top End

Sources: Accufab;accufabracing.com, Edelbrock;edelbrock.com, Holley/Hooker;holley.com, Lucas Oil;lucasoil.com, MSD;msdignition.com, Vortech Superchargers;vortechsuperchargers.com

Are you looking for BIG TIME power gains? Look no further than a Vortech supercharger!

There are many routes to increased performance. If we start with a stock motor, you can always upgrade the existing combination with a top-end kit featuring heads, cam and intake. If you want more, you can also increase the displacement of the short block. Of course there is always nitrous oxide, but if you are looking for serious power gains, nothing beats forced induction. Given the many forms of forced induction, the question is not do you or do you not choose boost, but which boost do you choose. Those looking for the absolute answer on which boost is best should look elsewhere, as the only true answer is “it depends”. Rather than focus on which one might be best, let’s focus on how awesome it is to have so many choices. The reality is that whether you choose a turbo, positive displacement or centrifugal supercharger, your combination really is Better With Boost.

To illustrate the power of positive thinking, we subjected an LS motor to boost from a Vortech centrifugal supercharger. Obviously there are countless LS combinations available and Vortech offers dedicated kits for many of the popular applications, but we chose to go a different route. Rather than run the test on a new Camaro or Corvette, we chose to go the wrecking-yard route. Nabbing a truck motor out of the local boneyard allowed us to not only demonstrate the benefits of boost, but do so at a more reasonable cost. Since 4.8L and 5.3L truck motors were built by the millions, they are both readily available and amazingly affordable. Not only that, they are also extremely capable, with plenty of performance potential just begging to be unleashed. Our test was run on a modified 4.8L truck motor, but boost can easily be applied to a bone-stock truck motor as well-though we highly recommend opening up the plug gap before running excess boost.

Stock will rock, but our 4.8L LR4 featured a few performance upgrades that allowed it to produce impressive power both normally aspirated and under boost. Remember, the power gains you make normally aspirated can be further multiplied under boost. If you run 15 psi like we did on this test, it is possible to nearly double the normally aspirated power gains so feel free to upgrade the motor before adding boost. During the rebuild, our 4.8L was first treated to a set of forged JE pistons to increase both strength and power. The slight dome offered an increase in static compression while the forged construction provided plenty of strength under boost. The remainder of the short block was box stock, including the block, crank and rods, though we upgraded the piston rings as well. The other power change we made to the short block was to replace the stock LR4 cam with a Stage 1 truck cam from Brian Tooley Racing. Perfect for the little 4.8L, the mild Stage 1 BTR truck cam offered .552 lift, a 212/218-degree duration split and 113-degree lsa.

Topping the modified 4.8L short block was a set of TFS Gen X 205 heads. The heads not only flowed significantly more than the stock 706 castings, but offered a spring package capable of keeping pace with the boost, cam lift and rpm potential of the supercharged combo. The TFS Gen X 205 heads were combined with the stock rockers and hardened pushrods from COMP Cams. Feeding the TFS-headed 4.8L was a stock truck intake and 78mm Accufab throttle body along with a set of 83-pound injectors from Holley. The injectors were chosen in anticipation of the elevated power levels of the supercharged combination. Also present was a Holley HP management system, 1 ¾-1 7/8-inch step headers and 5W-30 Lucas synthetic oil. After dialing in the air/fuel and timing curves, the 4.8L produced 398 hp at 6,300 rpm and 353 lb-ft of torque at 5,600 rpm. With our baseline out of the way, it was time for some boost.

For our test, Vortech supplied an LS kit that featured everything needed to apply boost to our 4.8L. Complete as usual, we applied only a portion of the supplied components in our test, including the self-contained V3 supercharger, mounting bracket (with tensioner) and aluminum discharge tube. As luck would have it, the 7.5-inch, ATI Super Damper run on a previous test with a Whipple supercharger lined up perfectly to drive the Vortech. All we had to do was mount the self-contained supercharger (required no oil drain hole in the pan), pop on and tighten the belt and then install the discharge tube complete with dedicated bypass valve.

The 83-pound injectors offered more than enough fuel to feed the supercharged beast, and after tuning, we were rewarded with some big numbers. The use of a 3.80-inch blower pulley put the peak boost pressure at 15.2 psi at 6,500 rpm. The elevated boost level brought serious power gains, as the little-supercharged 4.8L produced an amazing 699 hp and 565 lb-ft of torque. The rising boost curve meant that peak power and torque occurred at the same engine speed, so there was much more power to be had with more engine speed. Given the already elevated boost level, we will adopt intercooling before we attempt to make this combination even Better with (More) Boost.

The first thing you notice about the graph is that the supercharged power curve was still climbing rapidly at the 6,500-rpm shut off point. In fact, we had yet to reach the torque peak at that rpm, and the power peak would occur easy 1,000 rpm beyond that. The reason for this is the rising boost curve offered by the centrifugal supercharger. The increasing boost curve artificially increases the engine speed where the motor made peak power. Run in normally aspirated trim with the mild Stage 1 truck cam, the 4.8L produced 395 hp and 353 lb-ft of torque. After adding the Vortech supercharger to the mix, the peak numbers jumped to 699 hp and 565 lb-ft of torque. The pulley ratio used on the little 4.8L produced a peak of 15.2 psi of boost, which was too high for street use with pump gas. What this combination really needed was an intercooler.

Sources: Brian Tooley Racing; briantooleyracing.com, Holley/Hooker; holley.com; JE Pistons; jepistons.com, Lucas Oil;lucasoil.com, Trick Flow Specialties;trickflow.com, Vortech Superchargers;vortechsuperchargers.com

Baer’s new Drag Brake Kits cut 40 pounds from S550 Mustangs

By Cam Benty; Photos by Jonathan Ertz

Performance fans know power-to-weight is the magical ratio that makes slow cars fast and fast cars faster. So, reducing weight in today’s heavy muscle cars would seem like an obvious move, as long as safety and drivability are not compromised. Right?

The folks at Baer have an idea you probably didn’t know could be done: lightening the brake package on a late model Mustang, while improving the stopping power of the vehicle. Best of all, the install is a total bolt on — as long as you are clear on the rear end package on your specific vehicle.

Stylish and lightweight, Baer’s Drag Brake packages for 2015-18 S550 Mustangs improve braking and removes as much as 40 pounds from the rotating mass of the vehicle.

So, how much lighter did this make our street/strip project Mustang? With the package we chose, the total rotating mass weight savings was 40.4 pounds (8.6 front, 31.8 rear). That’s a huge difference that makes terrific sense, especially for street/strip cars that must serve double duty. Note that Baer also offers a true Drag Brake front brake package that achieves an even deeper weight reduction over the factory system for owners who will spend more time at the track.

With the personal investment required to own and modify one of these modern machines already stratospheric, clearly Baer’s engineers worked hard to build something performance fans can appreciate across the board. And the price won’t break the bank!

Installation notes

The upgrade for late model S550 2015-17 Mustangs is quite simple to install, for anyone who has ever changed brake pads on their vehicle. It is simply a matter of properly supporting the car, removing the wheel, unbolting the caliper, pulling off the old rotor, and installing the new Baer parts with fresh brake pads. In the case of the rear brakes, where you are replacing the calipers, the brakes will need to be bled to remove air from the lines — another fairly normal operation for brake upgrades.

Parts

The Baer Brake systems for S550 Mustangs are direct replacements for the heavy stock parts. With drilled, slotted, and directionally specific (one side is different from the other) high-performance aftermarket brake parts, the zinc-plated rotors are far better at managing heat dissipation and deliver stunning good looks.

The front rotors we used here are Baer’s EradiSpeed+ made for late model GT and EcoBoost Mustangs. We selected this since it offers a significant reduction in weight and is designed for cars that will spend the majority of the driving time on the street.

The EradiSpeed+ rotor found in this article uses two-piece brake rotors that work with the factory four-piston Ford calipers. The mounting “hat” that attaches the rotor is made from anodized black 6061-T6 aluminum for its light weight and extreme durability. Measuring 14 inches in diameter, they are as cool appearing as they are a functional improvement. If you have plans to go with smaller than 17-inch wheels, it is important to check for clearance — and is generally not advisable.

The rear drag brake package not only includes an 11.625×0.810-inch wide directional rotor that matches the earlier noted package for looks and attributes, but also a Baer SS4+ four-piston caliper. The latter bolts onto the stock spindle, so no additional cutting, grinding, or welding is required. While the rotor slips in place over the wheel lugs, the brake caliper swap requires full bleeding of the brake system — aided by a bleed kit that Baer offers for at-home, do-it-yourself folks.

Added features that may not leap out at you, according to Baer, are the specially designed rotor vanes apparent when looking at the narrow side of the rotor. The directionally-vaned rotor structure acts like a centrifugal pump, aiding greatly in cooling and fast temperature recovery in repetitive stops. In addition, National Aerospace Standard rotor hardware makes these rotors amazingly safe, which is why they can withstand racing and everyday use.

One point to note is that the Baer rear SS4+ Drag Brake system is not compatible with the factory parking brake. It does, however, use a very common Hawk (#HB540F.480) brake pad very popular with street performance Mustang fans. In addition, brake calipers can be had in either clear (natural) or red coloration standard, or any of a rainbow of colors for an additional fee.

On the road

In testing, the Baer Brake upgrade provided excellent stopping and retained all of the factory anti-lock braking features Ford intended. The reduction of weight is significant, especially since it is rotational weight that is magnified at higher speeds — so this is an exponential improvement as speed increases. This also means there is less clamping force required by the caliper to stop the centrifugal force of the wheel due to the reduction in weight. While this is hard to discern from behind the wheel, the reduction of force will help reduce wear and should shorten braking distance.

Better braking and 40 pounds less weight – that sounds like a winning combination.

Parts:
Front — (PN# 2261041) 14-inch rotor, front EradiSpeed+ Rotor
Rear — (PN# 4262695) 11.62-inch rotor, SS4+ Drag Race Brake System

Source: Baer Brakes, Baer.com

What do 5.0L Fords like better — Bolt-ons or Boost?

By Richard Holdener

When it comes time to modify your motor, there are a number of different routes available to improve performance. The most popular options include increased displacement, basic bolt-ons, and power adders (which include both boost and nitrous oxide). Spoiler alert: The best method to maximum performance is to combine these.

Start with a stroker, add the right heads, cam, and intake, then add boost and/or nitrous. This route obviously assumes you are both looking for every last ounce of power and have the means to afford it. For most of us, the choice of one is more than enough, and just the fact multiple avenues exist is reason enough to run a quick dyno comparison. After all, the All-Motor (bolt-on) guys don’t think much of the boost camp, and vice versa. Let’s see how the two compare on a small-block Ford.

In reality, our blue-oval test motor started out life already blessed with additional displacement. Rather than run the test on a stock 5.0L, we decided to step up to a 347 stroker assembly. Since we had to assemble all the components anyway, the 347 crank was no more expensive than a 302. The 3.40-inch stroker crank and 5.40-inch forged connecting rods were supplied by Speedmaster. The forged crank and rods were combined with a set of .030-over, forged pistons from JE to produce the desired 347 inches. The pistons featured valve reliefs that allowed us to successfully run both the stock 5.0L cam and the more aggressive XFI stroker grind from COMP Cams. It should be noted the 347 will be much more receptive to the bolt-ons than a smaller 302, as the additional inches can better take advantage of head flow and wilder cam timing.

The game plan for this test was to run the 347 stroker first with the stock 5.0L Mustang components, including the stock iron cylinder heads, camshaft, and a GT-40 intake (we didn’t have a stock H.O. intake handy for testing). Tuning each combination was a FAST XFI management system, so there was no need to run the mass air meter or attending air intake assembly. Having the FAST management system allowed us to quickly dial in each of the three different 347 combinations.

Additional components in the build-up included a Moroso oiling system, MSD ignition, and Speedmaster 28-ounce balancer. The GT-40 intake was fed by an Accufab 70mm throttle body, while fuel was supplied by a set of FAST 36-pound injectors. Exhaust exited through a set of Hooker 1 ¾-inch, long-tube headers into 18-inch collector extensions. Keeping things cool on the dyno was a Meziere electric water pump.

Run with the stock heads, cam, and GT-40 intake, the 347 produced peak numbers of 307 hp at 4,700 rpm and 401 lb-ft of torque at 3,300 rpm. Obviously, the mild cam and stock heads were greatly limiting the package, but that was all about to change.

The first modification on the list was to add boost to the current combination. This could then be compared to the bolt-on upgrades that included a set of RHS aluminum heads, wilder COMP XFI cam, and Edelbrock Performer RPM II intake. Boost for the stroker came from a Vortech S-trim supercharger. The Vortech S-trim required a dedicated oil feed and return back to the pan. We chose the Vortech S-trim both for its ease of installation (and testing) and for its ideal sizing for our low-boost and power needs. The Vortech was capable of supporting more than 750 hp — more than enough for our needs — yet was plenty efficient at lower power and boost levels.

The S-trim  supercharger was equipped with a 3.80-inch blower pulley and 6.75-inch crank pulley, which produced a peak impeller speed of 36,769 rpm at a peak engine speed of 6,000. On our 347 test motor, this equated to a peak boost reading of 8 psi at 5,700 rpm. The rising boost curve from 2.4 to 8 psi brought peak numbers of 421 hp and 462 lb-ft of torque. Even down at 3,300 rpm, the Vortech supercharger increased torque production of the 347 from 401 to 461 lb-ft, though the mild cam and stock heads were still limiting power production AND artificially increasing the boost pressure (really just back pressure) in the manifold. Now, it was time for the bolt-on brigade!

Off came the Vortech supercharger, as well as the stock E7TE, iron heads, GT-40 intake, and stock 5.0L cam. These mild components were swapped in favor of a set of RHS aluminum heads, an XFI hydraulic roller camshaft, and Edelbrock Performer RPM II EFI intake. We also stepped up to the larger 75mm throttle body from Accufab.

The dual-pattern XFI236HR-14 cam supplied by COMP Cams featured .579 lift (intake and exhaust), a 236/248-degree duration split (measured at .050), and a 114-degree lobe separation angle. The cam was combined with 200cc, as-cast aluminum heads designed as a direct bolt-on for hydraulic-roller cam applications. The RHS heads improved intake flow from 166 to 274 cfm, enough to support nearly 550 hp on the right application.

Topping the RHS-headed combination was the Edelbrock RPM II EFI upper and lower intake. Like the RHS heads and XFI cam, the RPM II represented a sizable jump in performance potential over the GT-40 intake. Equipped with the new, all-motor (bolt-on) combination, the power output of the 347 jumped from 307 hp and 401 lb-ft of torque to 448 hp and 420 lb-ft of torque.

Looking at the results, we see the 347 produced 448 hp with the bolt-ons and 421 hp with the Vortech supercharger, but (as always), the peak numbers do not tell the whole story. The supercharger improved the power output through the entire rev range, but the bolt-ons actually lost power below 4,000 rpm. In retrospect, a slightly milder cam profile might be a better choice on this 347 to help improve low-speed power production.

The boost level of the Vortech supercharger was as much a function of the lack of flow from the stock components as it was the ability of the supercharger. Boost is actually a measurement of back pressure in the intake system. If we ran the blower at the same speed on the bolt-on combo, the boost would decrease while the power output increased.  Restrictions in the system increase boost pressure, and flow gains (from ported heads, cam profiles, and better intake manifolds) decrease it. This should indicate the best 347 would be a combination of bolt -ons and boost, but we also know that independently, they offered impressive power gains as well.

Sources: Accufab, Inc., accufabracing.com; COMP Cams, compcams.com; Edelbrock, edelbrock.com; Holley/Hooker, holley.com; JE Pistons, jepistons.com; Speedmaster, Speedmaster79.com; Racing Head Service, racingheadservice.com; Vortech Superchargers, vortechsuperchargers.com

By Jeff Smith/Photos By Jeff Smith and CPR-Engines

It seems that the only engines that get any media exposure anymore in the popular media are 1,000-plus horsepower “street” engines. The problem with those big-power stories is that they do not represent what’s really going on. A turbo motor that can make 2,000 hp isn’t what the average street guy is all about. So we thought we’d follow along on a real street engine that was intended for a daily-driven ‘04 Corvette. Our pal Dan Livezey has been autocross racing for more decades that he cares to remember. Recently he picked up an ‘04 LS1 Corvette that supposedly had been rebuilt, but after a week or so, the motor started knocking heavily.

A subsequent teardown revealed that the LS1 had spun the Number 7 and 8-rod bearings. Dan took the dead LS1 to Martin Marinov at Custom Performance Racing Engines (CPR-E) with a plan to resurrect his engine. The combination they created would bump the displacement with more stroke, a touch more compression with forged pistons, some CPR-Enhanced CNC porting on the stock heads, a mild cam, and a better intake. Of course all of this was hinged on one other critical factor – they had to keep this engine at least appear to satisfy the smog police since Livezey lives in Southern California.

All of these points were essential factors for our build since loads of compression and a big cam just don’t play well when it comes to smog testing. It turns out that Marinov has some experience in this area and together he and Livezey hatched a plan that – because you’ve already cheated and jumped ahead to our dyno test – revealed this 383c.i. combination made an honest 550-plus hp on the dyno. Let’s see how they pulled this off.

Concept and Execution

The heads sport 2.02/1.60-inch stainless SI valves. CPR-E also milled the heads to bring the chambers down to 63cc from the stock 67cc.

The easiest way to make more power – even with an emission engine – is to pump the displacement. The only way to do that with any LS1 aluminum block engine is with stroke. The iron cylinder liners barely allow a 3.908-inch diameter bore so Marinov ordered a 4.00-inch stroke crank from nearby Scat to replace the original 3.62-inch version. Retaining its 24x reluctor count, Marinov then added a set of dished AutoTec 4032 alloy forged pistons designed to accommodate a set of 6.125-inch long RPM H-beam rods. The 4032 alloy contains a little shot of silicon to limit piston growth which allows a tighter piston-to-wall clearance, making these pistons much quieter than a typical 2618 alloy piston more commonly found in race engines. These pistons combined with a minor cleanup on the heads produce a 10.8:1 compression, which is pretty close to ideal for a pump gas LS engine.

CPR-E also does all its own machine work, which means the block was subjected to a line hone, simple decking, and a mild honing procedure using Rottler machines to make the block ready for assembly. Final assembly began with a set of King rod and main bearings and DuraBond cam bearings that can take the abuse of the mild increase in spring pressure without pushing out. Once the bearing clearances were set, CPR loaded up the COMP hydraulic roller camshaft and Rollmaster timing set to make sure the cam was where it should be. They also verified the valve-to-piston clearance since this cam is capable of over 0.600-inch valve lift on both the intake and exhaust.

Over their short period of time, CPR has developed a CNC porting package for the cathedral port heads that is pretty impressive. They start by adding a set of 2.02/1.60-inch stainless SI valves, machine the seats to this larger size along with their own multi-angle valve job again using Rottler equipment and then hand-blend the seats to the CNC porting to come up with some pretty impressive flow numbers. We’ve included a cylinder head flow chart that you can study at your leisure with some impressive intake and exhaust flow numbers. When you can squeak out over 300 cfm from a 227cc cathedral port head (200cc is stock), you’re achieving great flow plus maintaining excellent flow velocity, which usually pays off with great mid-range torque numbers as you will see. This LS head upgrade also includes of PAC springs set up with 130 pounds of load on the seat and 370 pounds of open pressure, just to make sure the valves stay where they are directed.

Testing

With the heads done, CPR-E wrapped up the engine build and bolted the engine on their in-house engine dyno. They began the test with the factory LS6 intake, stock 75mm throttle body and a pair of 1 7/8-inch primary pipe headers through open exhaust. As you can see from the power numbers, CPR-E’s very mild 383 made some fierce torque, which was exactly the plan. Even down at 3,000 rpm, the 383 thumped 446 lb.-ft of torque with a peak of 516 at 4,800 rpm. The 529 peak horsepower arrived at 6,100 rpm. That alone would have been newsworthy, but then CPR-E bolted on a FAST LSXr cathedral port intake manifold and a 104mm FAST throttle body. Both the new LSXr and the original factory LS6 intakes mounted a set of FAST 46 lb./hr. injectors to make sure the engine didn’t run out of fuel, since the stock injectors promised to be a little on the small side to feed this much power.

With the FAST manifold and larger throttle body bolted on, the 383 again pushed through the power curve and after a little WOT-tuning on the stock ECU, the numbers surged. All you have to do is look at the graph to see how the FAST manifold bumped the power curve up across the entire rpm span from 3,000 to 6,400 rpm. There aren’t too many aftermarket parts that can pull of that kind of broad power magic across a 3,400-rpm span. As for the specific numbers – the most important really isn’t the peak torque at 528 lb.-ft at 4,800 or even the 556 peak horsepower number. The most impressive number is the average 14 lb.-ft improvement across the entire power curve. Add to this a minimum of 500-plus lb.-ft from 3,800 rpm to 5,600 rpm and the fact that the torque never dropped below 450 lb.-ft over the entire curve and those are some outstanding numbers. True, all this comes at a price. The induction package comes to more than $2,000 for the manifold, throttle body, fuel rails and injectors. But short of a supercharger or nitrous, it’s hard to come up with something that can add power across such a broad power band.

That means this engine will deliver excellent drivability and fantastic acceleration while still delivering near-stock idle characteristics. This engine should also be able to pass a California emissions test even with the LSXr manifold in place since it has a California Executive Order (E.O.) number, making it a legal manifold with the smog police. Owner Livezey is currently hunting for a set of headers that also offer the same E.O. clemency. Of course, there’s bound to be a minor power loss when the engine is bolted in the car since it will have to breathe through the Corvette’s street exhaust system but that should present only a minor decrease. Frankly, the torque will probably suffer the least, and that’s exactly what Livezey intends to rely on the most. As we said, Livezey is an autocross racer, so you can expect to see his ’04 Corvette at more than its share of local Los Angeles autocross challenges. Be prepared to discover he is quick behind the wheel!

CPR-E Flow Numbers

This chart compares the stock 243 LS1 cathedral port head with CPR-E’s CNC-ported , 227cc version with 2.02/ 2.160-inch valves, a CPR-E valve job and some minor hand blending. The E/I column is the exhaust-to-intake flow relationship. Generally, the higher the percentage of exhaust flow compared to the intake, less additional exhaust lobe duration is required to help the engine make horsepower.

Cam Specs Chart

Power Curve

The two tests plot the power difference between the stock LS6 intake and the major torque and horsepower gains offered by the FAST LSXr intake and 102mm throttle body. But don’t overlook how much torque this 383 makes. How many street 383’s on pump gas have you seen that make 500 lb.-ft of torque at 3,800 rpm?

Parts List

Sources

COMP Cams
compcams.com

Custom Performance Racing Engines (CPR-E)
cprengines.com

Fuel Air Spark Technology (FAST)
fuelairspark.com

King Bearings
kingbearings.com

Melling Automotive Products
melling.com

PAC Racing Springs
racingsprings.com

RaceTec Pistons (Auto-Tec)
racetecpistons.com

Racing Parts Maximum (RPM)
racingpartsmaximum.com

Scat Enterprises
scatenterprises.com

SI Valves
sivalves.com