More than sixteen years ago GMHTP was founded to serve the enthusiasts of what was then defined as late model muscle cars. The qualifier for this title being the engine was equipped with electronic fuel injection and ignition control. As time progressed the EFI community has grown in both number and ability, but there still remains a good deal of mystery around the concept of calibrating an engine. This is rooted in two distinct but different domains: understanding what an engine wants and how to use the software of the specific engine controller you have.

Heat is the enemy. It’s been the enemy since the very first internal combustion engine fired up well over 150 years ago, and will continue to be the enemy for, well, forever. This isn’t an engineering obstacle; it’s a fact of life and, unfortunately, not something a bunch of car guys are going to "fix" just because it would help us run faster at the track. As temperature rises (assuming pressure and volume stay the same, which we are going to do) density drops, which reduces overall power production. Remember, the more air molecules (volume and density) you can stuff in the cylinder, the more fuel you can add and the more power you can produce. If the Ideal Gas Law wasn’t bad enough, hotter air also increases the likelihood of pre-detonation within the combustion chamber (AKA knock), which left unchecked, will turn shiny new pistons into paperweights before you can even lift out of the throttle.

Nothing says hot rodding like dipping into the stock parts bin at GM, mixing and matching OEM components, and coming out the other side with almost 50 extra rear wheel horsepower and OE reliability. This trick, of course, is as old as the internal combustion engine itself, although it’s just recently that a couple hundred dollars worth of GM parts could add this kind of power. Seriously, the package we’re showing off here can be purchased for under 300-bucks if you shop smart (new parts, nothing used) and added 47-rwhp and 20 lb-ft of torque to our bolt-on equipped 2011 Silverado LTZ, through the factory automatic transmission. Besides the healthy power gains, we also drove away with a near stock idle, sublime under-the-curve drivability, long term reliability, and a stop light ready sleeper package that could surprise almost anything you’ll run into on the street. And the best part is, anyone can get this done with a couple hundred bucks and a 6.2-liter LS engine, which means the LS9 camshaft swap will work for a ton of truck guys, and fifth-gen Camaro enthusiasts as well. In fact, AntiVenom recently stuffed a 6.2 in our Ashy Larry project, with the same camshaft, and made over 400-rwhp!

"What happened back there? How did he end up passing you?"

Superchargers are no big secret to making horsepower. In fact, their use on production cars dates all the way back to the 1920s. In today’s market there are many types of superchargers and a multitude of kits for the 2005-2013 Corvette. Clearly the willingness of Corvette owners to modify their cars, combined with the desire to keep up with new Vette models (such as the 7.0L Z06 and the supercharged ZR1) as well as foreign competitors has inspired many to purchase various methods of forced induction. Due to the very tight packaging constraints, many consider positive displacement blowers, such as the Eaton TVS2300 on the ZR1, to be superior on most street cars and others maintain that the compromises are worth it to install a turbo kit. However, yet a third avenue combines the best of both worlds, providing the best thermal efficiency and a high ceiling for producing horsepower – centrifugal superchargers. Yet even in this market, there exist many choices. Ours was ProCharger.

Those of you longtime readers may remember our good friend and fellow SIM Editor, Mr. Jay Heath, the former owner of our ’99 LS1 Trans Am project that raucously pounced Englishtown Raceway Park with such proficiency using mere bolt-ons until its final days when it received a ProCharger. Jay has owned several Firebirds over the years, and once again decided to return to the Big Chief. But the problem he faced was one that no doubt many of you have, if you were in the market for a fourth-gen recently. He wasn’t willing to pay C5 money for a fourth-gen LS1, and there wasn’t much in that price range that didn’t need significant work (if it was salvageable in the first place). Thus came the nearly regrettable thought of purchasing a V-6 Firebird and using the leftover money to convert it. Now for a gutted racecar, using a V-6 car is a no-brainer. But if you actually want functioning OEM gauges, creature comforts, and reliability suitable for a daily driver—that is going to take time, effort, and some real craftiness.

New generations of small-blocks are generally accompanied by fanfare, ticker-tape parades, and claims of the greatest thing since Nutella hit sliced bread. But will some ignore the Gen V release as a simple marketing ploy for an LS engine that just has its fuel injectors in a different place? That would be a poor choice on their part, because not only does the new LT1 differ significantly from all small-blocks before it (and is easily the biggest thing since the LS1), its advancements work together to simultaneously increase fuel efficiency, lower emissions, and bump power potential. And while the Gen 5 is sure to bring new challenges to the aftermarket, so did the LS1… then as now, opportunity knocks for talented folks who are brave enough to blaze new trails.

Porting cylinder heads has long been a right of passage for serious hot rodders looking to add power on a modest budget. Armed with the right knowledge, the correct tools, and a couple of nights in the garage, it’s an easy and almost free way to pick up airflow, which results in increased power and decreased e.t.’s at the track. However, with the wrong knowledge, or an overzealous hand, home porting of cylinder heads can literally ruin a set of castings, taking them from a quality off the shelf piece to a set of paperweights in less than a minute. And because of this, it’s pretty difficult to find anyone out there willing to show the ins and outs of a hand-porting job, since it’s easy to put the wrong info into the wrong hands. Well, that, and the fact that cylinder head porting is more akin to a witches’ brew of knowledge and experience than a straightforward bolt-on modification. But that doesn’t mean there isn’t hope for the budding enthusiast looking to modify a pair of heads in their free time and try them out on the engine of their choice.

If it seems like every Camaro since the third-gen has come with a woefully inadequate rear end package, it’s because they have. Third and fourth-gen fans knew this pain all too well, with the anemic 10-bolt rear wreaking havoc on ring and pinions since the first models hit the dragstrip way back when. For enthusiasts, it was a frustrating time, with almost no aftermarket options for a true plug-and-play rear end upgrade solution. Today, “old” Camaro owners have almost too many options, with manufacturers building drop in rears for practically every single application. Now, one would have hoped that the fifth-gen Camaro design team would have addressed this issue, but following in the footsteps of its predecessors, GM engineers seemed to have once again taken the “less is less” approach to the rear, with a weak differential, a small ring and pinion, and small axle shafts leaving hardcore drag and street users fearing for the worst every time they drop the hammer out on the track.

It’s always tempting to start out a story about a V-6 build by comparing it to its bigger brother, the V-8. So, lets do that… One engine ships from the factory with a single camshaft, pushrods, two valves per cylinder, cast iron exhaust manifolds, 10.2:1 compression, and standard electronic fuel injection. The other features dual overhead camshafts with infinitely variable cam phasing, 4 valves per cylinder, integrated aluminum exhaust manifolds cast into the factory heads, individual cylinder knock control, 11.5:1 compression, and state-of-the-art direct injection. One produces 1.14 horsepower per cubic inch and the other produces 1.48 horsepower per cubic inch. One of them is world renowned; the other is just a V-6. Except, the one you’re probably intrigued by here isn’t the big cube V-8, it’s probably the really high-tech and incredibly well thought out V-6 mill, known to many fifth-gen owners as the LFX. Of course, for all that the 217 cubic-inch DI VVT V-6 can do, there is one major area where it may be lacking: power. With the V-8 at rated at 430 and the LFX at 323, it’s a hard argument to win with muscle heads, even given all of the technological data.

Perhaps the concept of trickle-down economics isn’t all that far-fetched. Case in point: your author (or more correctly, his old man) recently picked up this virtually flawless, 52,000-mile C5 Z06 for just $19,000 – a full thirty grand less than it went for new. Yes, the world-class supercar we know as the Z06 has finally dropped into the econocar price bracket, and should the Corvette divinities see fit for the C6 versions to one day near this level of affordability, it will surely be the best of all possible worlds.

This is the article where we tell you that 10-bolt in the STI Killer finally broke and you get to write us letters saying, “we told you so!” And, that’s fine; bring on the mail. Seriously, I like getting mail…send it. Regarding the business at hand, if you recall, the Killer has been running a factory supplied 10-bolt since the beginning (we originally built it in the August 2010 issue) and it’s been stuffed with the best goodies we could find, and even narrowed for our new wheels, for the entirety of the project’s life. But, for all that was great about the little 7.625-inch rear, it eventually did what they all seem to do and managed to chip a couple of teeth off the ring and pinion. Unlike many a 10-bolt of the past, we managed to do this one on a particularly nasty downshift (no brakes into a hairpin at Sebring) and still got lucky enough to take the car to the CHP Nationals and make a couple of passes before the rear said goodbye for good. Physical carnage aside, we never really got to launch the car hard at the track, and we always knew it was just a matter of time before this happened, so there really was no love lost seeing the ol’ rusty 10-bolt head on out the door, even if we knew it meant hearing “I told you so” from every e-thug with an email account.

Mere milliseconds after the first 2013 Shelby GT500 testers were released, auto journos wet their collective tighty whiteys. It has 662 horsepower! It’s the baddest factory V-8 in the history of the universe! It could theoretically, in perfect, absolute zero, Magic 8 Ball conditions, go 200 mph!

You would be hard pressed to find a single GM guy who doesn’t crack a smile at the thought of owning a CTS-V. Back in 2004, GM was firing on all cylinders in spite of slaying the brands’ two muscle cars, the Camaro and Firebird. This period of time saw the emergence of the new GTO, the best Z06 in the C5 body style, and a total image rebranding for Cadillac. These LS-powered machines were some of the best muscle GM had produced in years, but there’s always room for improvement.

Those of you longtime readers may remember our good friend and fellow SIM Editor, Mr. Jay Heath, the former owner of our '99 LS1 Trans Am project that raucously pounced Englishtown Raceway Park with such proficiency using mere bolt-ons until its final days when it received a ProCharger. Jay has owned several Firebirds over the years, and once again decided to return to the Big Chief. But the problem he faced was one that no doubt many of you have, if you were in the market for a fourth-gen recently. He wasn't willing to pay C5 money for a fourth-gen LS1, and there wasn't much in that price range that didn't need significant work (if it was salvageable in the first place). Thus came the nearly regrettable thought of purchasing a V-6 Firebird and using the leftover money to convert it. Now for a gutted racecar, using a V-6 car is a no-brainer. But if you actually want functioning OEM gauges, creature comforts, and reliability suitable for a daily driver – that is going to take time, effort, and some real craftiness.

There are few things more gratifying than a brand new paint job on your pride and joy. Like the finishing touches on any project, a paint job can take a regular 10-footer and turn it in to a real showstopper. In the case of the Purp, our on-going NMCA LSX Real Street project, any paint would have been better than what we started with, but since we’re not sure how competitive the car will really be (thanks Preston…), we had to be sure it looked good while attempting to make the show. Plus, it’s always fun to have a fresh color on your project, especially after pushing it around for so long wearing the dented, faded body that we started with.

If you're one to keep an eye on LSX Drag Radial racing, it's likely that you've already seen Mike Meeks' brand-new fifth-gen project out on track. Last we left you, Mike was almost finished with his insane 90-day project build, in which he was tasked with building a competitive race car from scratch using nothing more than a Body-In-White '10 Camaro shell and a helping of parts off of his old fourth-gen Pontiac Trans Am racer. As a guy who takes a year to diagnose a brake problem (me), building anything in 90 days is just insane, let alone a Camaro that should run well into the 7-second range on a drag radial and in the heat of competition. But, that's why we chose to follow Mike's build, instead of our own, since we knew Mike could get it done. It should come as no surprise to anyone that a build of this nature requires a significant investment of time, money, blood, sweat, and tears. At this point, almost everything is custom, with parts coming out of a box, onto the car, and then back out to be modified to work. Because of this, a lot of what you will see here may not apply directly to anything you're currently building, but it's a rare look into building something of this caliber. Plus, we're sure you can pick up a tip or two here and there, just make sure you study all of the photos and really read in between the lines. This is racing after all, not everything is going to be cut and dry.

The answer, of course, is True--provided you replace "plenty of" with "a distinct lack of." The hatch of your Corvette or fourth-gen Trans Am might be a great place for a few grocery bags or some take-out, but that's about it. (Let's not even mention the trunk space in a GTO.) Try buying all the supplies you need for that woodshed you've been meaning to build in the backyard, and you're gonna come home with little more than a couple cinderblocks and some screws. Surely this comes as no revelation to you, so there's a pretty good chance there sits a GM truck in the driveway to take care of such dirty work while your prized muscle machine gets its beauty sleep in the garage. If this truck happens to be a Chevy or GMC packing an LS engine, you've struck gold--it's ripe for many of the same mods you probably have already done to your muscle car!

For everything that is amazing about the new ZL1, there is one major problem. It's called the GT500, and as far as stock for stock horsepower is concerned, it's not even close. While the ZL1 rolls from the factory with an amazing 580 hp, the GT500 slays it with a conservatively rated 662. On paper, that's 82 hp, but in the real world we've seen as much as a 100hp difference to the tires. It sucks, but there isn't anything we can do about it. Actually, that's not true, there is a lot we can do about it thanks to the awesome aftermarket support pouring out from speed shops across the country. And, when you really think about it, who cares what it belts out stock? We never leave anything stock around here and neither do you…

There is a section near the end of the Texas Mile rule book entitled Automobile-Required Safety Equipment (At or Over 215 mph) and it's where things start to get real if you're building a car of this caliber. Fire extinguisher, helmet, safety belts--that's all the easy stuff. The cage rules are where it gets exciting. "All cars that are attempting speed at or over 215 mph are required to have an eight-point rollbar at minimum. The materials and minimums are as follows..." Under 3,000 pounds, the cage rules are fairly similar to a drag race setup; over 3,000 and you are required to run large 1.75-inch round DOM with thick .120-inch walls, and, as stated above, it's got to be a minimum of 8 points to pass tech. If you're thinking that's relatively "small" for a car going 215, try to keep in mind that there are no walls to hit on the runway (well, hopefully anyway) and there isn't another car to get tangled up with. Really, for an impact, you're going to have to end up in a rollover situation, which is why door bars combined with a solid main hoop (and rear X-brace) is a good idea. Now, where can one even get a large 1.75-inch 8-point cage these days?

The Purp's saga continues this month as Pro Fab Performance secures our freshly painted VFN hood, and makes room for a taller intake. Rewinding for a second, last month we made a trip up to North Deland Auto Body to smooth out the body and receive a few coats of Matrix's version of GM Spice Red Metallic (from the '05 GTO). Before we did, though, we had to figure out how we would be securing the VFN Sunoco hood. While at first we were inclined to go the full lift-off, pin-on route, having hood struts is particularly nice for those of us that don't travel with a full race team. Several of Pro Fab's X275 builds have used Aerocatch fasteners, and we've always been a big fan, so this was an easy solution for a sleek set of hood pins that would save weight. Prior to paint, Matt Larue made the careful cuts in the hood, and once back in our possession Matt would have to screw the top piece to the hood and install the pins onto the radiator support.

Without question, it's fun to buy, build, or drive a street sleeper--a car that is much faster than it looks. General Motors hit the nail on the head when it unveiled the Pontiac G8 GT, as it has all sorts of awesome features to make for a very fast car, while the sedan body style certainly throws people off course. Regardless of the car's sleeper status from the factory, we wanted to pep it up a bit, without giving away too much of the car's quiet and non-descript attitude.

You love late-model muscle cars, but do you understand what makes them tick? Do you know why your '10 Camaro SS not only has more power than equivalent cars of the '60s, but also with vastly better drivability and fuel economy? Why the 1980 Turbo Trans Am was a lackluster machine, but the 1989 model was such a killer? There are a lot of reasons that engines experienced such improvement, and so many of them boil down to Electronic Fuel Injection. EFI so revolutionized hot-rodding that the original High-Tech Performance magazine was born (and became GM-only in 1998). Back then, GMHTP readers were a distinct minority compared to those who thought carburetors would forever reign supreme, but today even the most diehard old-school aficionados have been converted after seeing the incredible combination of power levels and drivability EFI makes possible. These days, you probably take EFI as a given, but it wasn't like this 15 years ago. Back then, many saw it as a hindrance to backyard mechanics fixing or modifying their own vehicles. To love EFI requires knowing the ins-and-outs of how it functions, so we figured a "get to know your EFI" article was in order. After all, there's a lot of unseen business that goes on between the time gas is pumped into your tank and it ends up as motion down the road; this article should be a good first step at figuring it all out.

In our last episode (April 2012), we strip-tested our buddy Tim Cairone's Turbo Buick in its latest state of tune (365 rwhp, 554 lb-ft at 18 psi). With all that torque, we knew it needed help getting the power to the pavement. So we ordered Air Lift airbags from G Body Parts and a Lift Bar Set-Up (lower control arms with relocation brackets) from UMI Performance. Each component was installed and individually tested at Atco Dragway on different track days.

It's often said that some of the most innovative stuff going on in the world happens in the most unassuming places. You know the clandestine shop in the middle of nowhere churning out killer work and trying to compete with the big dogs. Take, for example, Nate Shaw of One Guys Garage and his plan to build a budget corn-fed 5.3L LS motor that pumps out some serious steam with a fab'd single turbo kit. We really perked up when we heard his budget: less than $6,000. For Nate, though, the key was building a combo that would last, and not just a two-pull dyno queen, since he'll actually be dropping this motor into a car.