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Chevrolet Camaro STI Killer - A Killer On The LooseThe STI Killer Hits The Dragstrip, Road Course, Skidpad, And Dyno For The First Time Ever And We Get Our Baseline Numbers For Each From the January, 2011 issue of GM High-Tech Performance By Justin Cesler Photography by Justin Cesler, Scott Parker
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There are few moments in life quite like the first time you actually get to drive a new project, whether it was just a simple engine modification or an entire rebuild. For me, the moment came right before lunch on a Monday, after three all-nighters in the shop trying to get the STi Killer ready for battle. After grabbing the last of the supplies from the parts store and filling the radiator with water, I nervously climbed into the driver's seat and turned the key. After just a second on the starter, the STi Killer fired to life and the GMPP LS6 sounded amazing. After verifying that nothing was spewing from the engine bay, I slowly pushed in on the clutch, slid the shifter into reverse and began to back up. "We're taking this car to lunch!" I proclaimed-just moments before the Camaro ground to a halt and the clutch pedal dropped to the floor. OK, I was prepared for this, I figured something would happen, but this seemed like a much bigger deal. Defeated, I pushed the car back onto the lift and rode to lunch, again, in a car other than the Camaro. There is no feeling quite... There is no feeling quite like the first time you fire up your new project. For us, the initial testdrive was short lived (about 6 feet), but with a couple of easy fixes, we were back on the road and feeling good! When we returned, I started digging and luckily found that our clutch problem was a simple fix. Turns out, you do in fact need that little clip on the clutch pedal to hold the master cylinder rod to the pedal (PN 3817880). After a quick trip to the dealership, we were back in business (thanks to Marc "tiny hands" Christ, of Muscle Mustangs and Fast Fords fame) and I was finally able to take the Camaro on its maiden voyage, a trip around the parking lot, over the main street in front of our world headquarters and over to the gas station, to fill the Camaro with 13 gallons of 93 octane. Upon return, I deemed the STi Killer "ready for war" and after a cool down and double-check, it was time to see what the STi Killer was really made of. Dyno Results
Before we could hit the track with our new setup, we had to verify that the entire drivetrain was in good working order and that our tune-up was spot on. For this, we loaded the STi Killer on our in-house DynoJet 224xLC, brought it up to temperature and made some baseline dyno runs. Using a combination of tools, including the built-in DynoJet wideband, our own Innovate LM-1 wideband, and a copy of HP Tuners, we were able to monitor everything our project was doing and change any parameters of the tune that needed tweaking. With just under 20 miles on the odometer, we laid the hammer down for the first time, recording 394.4 rwhp and 378.6 lb-ft of torque! Trust me, we were as surprised as you are, 394.4 from a GMPP LS6 with bolt-ons did seem optimistic, but we backed it up with another pull and everything checked out. It seems that the combination of our traditional bolt-ons, along with the small horsepower freeing modifications we have made along the way all worked together to belt out some serious power. In comparison, our Subaru STi made 230 awhp and 260 lb-ft of torque, which means in the horsepower wars, the Camaro clearly reigns supreme.  After a quick spin around...  After a quick spin around the block and a couple of heat cycles, we loaded the STi Killer up on our in-house DynoJet 224xLC and made a couple of baseline pulls. The GMPP LS6, D&D Performance T56, and AntiVenom 10-bolt had roughly 20 miles on them before this point.  Yes, you are reading that...  Yes, you are reading that correctly: 394.4 rwhp and 378.6 lb-ft of torque. For a stock GMPP LS6 with a couple of bolt-on parts, we were incredibly impressed. Chalk it up to a good combination, a strong factory engine, and some beginner's luck.  Happy with our base tune and...  Happy with our base tune and numbers, we loaded up the STi Killer and drove up to Gainesville Raceway to baseline our Camaro on track. That's me in the driver's seat, making some last minute changes to the tune and starting the datalogger.  For consistent and reliable...  For consistent and reliable testing, we are going to rely on a plethora of high-tech goodies. What you see here is our HP Tuners equipped laptop, an Innovate LM-1 wideband controller and a Racepak G2X GPS data acquisition unit.  One year, two months, and...  One year, two months, and ten days later, our project Camaro finally made its first dragstrip pass. Right off the trailer (it's not insured or registered yet), the STi Killer ran a 13.14 at 112.07 mph, using a set of Nitto NT05 tires and the stock, untouched springs and shocks.  Back in the staging lanes,...  Back in the staging lanes, we reviewed our datalogs and found some interesting issues. First and foremost, our stock LS6 injectors were recording abnormally high injector duty cycles (118 percent at 116 mph), a problem that would later come back to haunt us.  We also found a pair of incredibly...  We also found a pair of incredibly high temperatures within our datalogs. The most troubling, however, was the Intake Air Temps (IATs), which were over 150 degrees in the staging lanes and over 130 degrees at 116 mph. We told you it was hot at Gainesville during our testing!  After a couple of changes...  After a couple of changes to the tune, using HP Tuners, we managed to click off our first 12-second pass, running a 12.996 at 110.02 mph. You can see how poorly the car transferred weight, a problem that would only get worse throughout the day.  We tried to add some fuel...  We tried to add some fuel to the tune, to help richen up our Camaro's air/fuel ratio, but even with massive changes we couldn't get out of the low 13s (AFR). A quick check with the fuel pressure gauge confirmed our suspicions, our stock fuel pump was going bad, only able to hold 40 pounds of pressure at 5,000 rpm.
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