If you read the wrong magazines, peruse the wrong forums, or spend too much time looking through parts catalogs, you may come away with the general consensus that every single piece of your car, whether modified or stock, is a horrible piece of junk that's seconds away from exploding. We've all been there, researching the next high-tech part to buy when someone with a closet full of go-fast goodies, a drained bank account, and a car with enough parts to run 8's that actually runs 12's chimes in with, "That will never work! Those are junk and you can't ever go fast with them. My boy said..." This happens, all day, every day to every type of enthusiast. Sometimes, this terrible advice leads to spending thousands upon thousands of dollars for a new engine only to find out it goes just a little faster than the "stock junk" and has oiling issues. For others, it can lead to part paralysis, a condition in which too many choices and too many opinions leads to never making a decision and instead deciding to just remain unhappy with your car, since everyone says it must be terrible.
Then, there are people like Chris Johnson--the most rare breed--racers who believe in steadily tweaking a combination based on actual track data, empirical evidence, and time spent under the hood. Guys like Chris don't usually waste energy arguing with people on the internet or working two jobs just to pay for the newest part to come out in stores. Oh no, racers like Chris spend way too much time wrenching, tweaking, tuning, and studying to do that. And it's that difference that allows Chris to run as fast as 10.08 at 131 mph on a 1.291 sixty-foot with a 346-cube LS1...with a stock rotating assembly...on motoràwith a 4L60E...at 520-rwhp!
Yeah, Chris' car may look like a radical beast and it is certainly fast, but what makes this a GMHTP feature car and one of the most impressive LS1's in the country isn't what he has done to it, but rather what he hasn't. "Ever since I bought the Z28, it has always been a strong runner. Even in the early stock internal days running mid-11's, it has always responded well to modifications. It has slowly evolved from a stock internal daily driver to a heads/cam weekend warrior. The main goal of the car was not to ever trailer it to the track, round trip is 160 miles and it doesn't miss a beat." Oh, yeah, he drives it to the track, puts it on the back bumper, runs bottom 10's and drives it back home.
"I have done all the wrenching on my car from day one. Some call it a trust issue, I just have to know what is going on inside my car so the only one to blame is me." Luckily, Chris doesn't have to blame himself too often, as his Z28 practically runs like a stock LS1. In fact, 70 percent of the engine is still factory stock, with the stock LS1 engine still nestled between the shock towers, topped with only a pair of 215cc Trick Flow Specialties cylinder heads and a relatively tame 239/243-duration, .624/.624-inch lift camshaft cut on a 111+4 LSA. Now, those heads do have some trick parts inside, including a set of LS3 hollow stem intake valves that Chris had turned down from 2.16-inches to 2.04-inches by Total Engine Airflow, a move that saved "27 grams of weight in the valvetrain" and helped Chris pick up a significant amount of power on both the dyno and track.
Above the heads, Chris runs a FAST LSXR 102mm intake manifold, which he hand ported to maximize its efficiency and flow. According to many, the 102mm is simply "too big" for a 346, although this is just another example of testing for your specific combination and tweaking a piece to work for a specific goal. Bolted to the front of the intake is a PTM 102mm throttle body, which pulls air through a custom ram air system that Chris designed himself. "I designed and built the custom ram air system for my car four or five years ago on the quest for more horsepower. I like it because many people overlook this modification and it is kind of a sleeper. But the 2.5 mph (25 rwhp) at the track says different. The whole reason I made it is that there is nothing on the market that allowed minimal modification to the car but had max effort results produced. It was one or the other." That was, until the crew at Speed Inc. caught wind of Chris' new system and contracted him to build and stock the "Chris1313 Ram Air system," a modification you can go out and buy today if you're looking for similar results.
Behind the motor, Chris runs a set of American Racing 1-7/8-inch long-tube headers which flow into a--you guessed it--custom-built off-road Y-pipe and, depending on where he is at, a stock Camaro cat-back or straight into the atmosphere through the open merge. In another "impossible" move, Chris puts all of this power down through a 4L60E, which he had upgraded by Finish Line Transmission to Level 6 specifications. A Yank 4000-stall gets everything spinning and, as you would expect, a stock shifter makes it all work. Hey, if it ain't broke, don't fix it! Speaking of broke, the stock 10-bolt is obviously out of this equation, replaced by a Strange 12-bolt that has been shortened 2-inches per side and stuffed with a 4.10:1 ring-and-pinion, 33-spline axles, and a steel spool. "The car has always handled like an arrow. It launches straight every time and is very consistent with the automatic. Those 1.29-second sixty-foot times sure throw you back in the seat and you see sky for a good second or two."
"My new goal is to hit a 9-second time slip with the heads and cam setup. It has gone a best already of 10.08 at 131 mph. The time was done in the heat of summer on an 85-degree day." Last fall, while still running a 92mm FAST intake and the stock Trick Flow valves, Chris had the ride of his life when "it went on the back bumper for a 175-foot wheelstand. For one moment, the car had all four tires off the ground. When the back two tires regained contact with the track, it threw me aiming at the wall, so I had to let out 100-percent from the throttle and let it come down hard. It crunched my headers and almost took out my oil pan." His only regret? "I only wish there was a video of it."
So, there you have it. An oh-so-close to 9-second street-driven F-body with a stock bottom end, no power adder, a 4L60E transmission, and one incredible builder. Proof positive that too much e-arguing and spending money on expensive parts is not only bad for your wallet, it's bad for your car. If you can sit back, make a game plan, and tweak a solid combination over time, you too can go wheels up with Chris and drive back and forth to the track, a feat only made more fun and rewarding when you get to beat racers with hopped up engines, twin turbos, six-figure fuel systems, and nothing but excuses.
|2002 Camaro SS|
|Heads:||Trick Flow Specialties 215cc, 2.04 intake, 1.575 exhaust valves|
|Cam:||Custom hydraulic roller, 239/243 duration at .050, .624/.624-inch lift, 111+4 LSA|
|Rocker arms:||Yella Terra, 1.7-ratio|
|Crankshaft:||Stock, nodular iron|
|Rods:||Stock, powdered metal|
|Throttle body:||PTM 102mm|
|Fuel injectors:||38 lb/hr|
|Ignition:||Stock coil-near-plug, NGK TR6|
|Engine management:||Stock, tuned by Jim Moran at Speed Inc.|
|Exhaust system:||American Racing 1 7/8-inch long-tube headers, custom 3-to-4-inch Y-pipe, open (track), stock exhaust (street)|
|Transmission:||4L60E, built by Finish Line Transmission|
|Driveshaft:||PST 3.5-inch, aluminum|
|Front suspension:||QA1-R shocks, 275-lb springs, removed sway bar, UMI tubular K-member, Madman travel limiters|
|Rear suspension:||Stock shocks, stock springs, BMR subframe connectors, Midwest Chassis adjustable torque arm, UMI lower control arms and anti-roll bar, UMI Panhard, Spohn drag bar|
|Rear end:||Strange 12-bolt, 4.10 gear, 33-spline axles, steel spool|
|Brakes:||Strange, front and rear|
|Wheels:||Billet Specialties Street Lite 15x3.5 front, 15x10 rear|
|Front tires:||Moroso DS2 165/80/15|
|Rear tires:||M/T ET drag radials 275/60/15|