On Cartek's Dynojet, the turbocharged LS1 put 671.9 hp (at 6,000 rpm) and 676 lb-ft of torque (at 5,200 rpm) to the rear wheels. |
Not far from the mufflerless tailpipe, you'll find the STS turbo using spent exhaust fumes to power a turbine shaft. Fresh air is pulled into the compressor housing and sent out of the side of the turbo to be fed into the intake tubing, the intercooler, and into the motor at the tune of 14 pounds of boost. |
That cage you see is actually custom-made from 13/4-inch-diameter (painted) chrome-moly by Neverlift Racecraft, Spotswood, New Jersey. Aside from it, the shifter, and some added instrumentation, the interior remains surprisingly stock. |
Auto Meter gauges keep tabs on underhood vitals, and the shifter is a Hurst pistol grip Quarter Stick. |
For those unfamiliar with the Squires Turbo System design, it's a rear-mounted turbocharger that relies on spent gases to produce power with no parasitic effect on the engine. Kooks stainless steel 13/4-inch headers with 3-inch collectors expel exhaust gases through 3-inch exhaust pipes to the Squires Turbo Systems turbocharger, which is mounted in place of the muffler. The high-velocity exhaust pressure spins the turbocharger's turbine shaft, and after fresh air is drawn into the compressor and boosted, it is delivered to the engine through a 28x10x4-inch air-to-air intercooler at 14 pounds of boost.
Of course, without some engine management, everything would go haywire. For this, a Big Stuff 3 computer system allows the boost to be increased or decreased without changing the custom programming, while an Auto Meter gauge pod near the dash monitors boost, trans temp, oil pressure, water temp, and fuel pressure.
With the engine ironed out, the transmission was next. A built-to-the-hilt Turbo 350 with a manual valvebody and transbrake was put in place of the stock overdrive automatic. Torque is delivered via a Vigilante converter with a stall speed of 3,600 rpm and a B&M trans cooler improves durability.
To fit all this in, a couple of modifications had to be made. For the underbelly, Cartek built a custom, one-piece steel crossmember, and a one-piece BMR driveshaft connects the entire mass to the mostly stock--yes, we said stock--limited-slip independent rear and its 3.46 gearing. Thankfully, stronger BMR stub shafts were installed.
Keeping the ride steady, adjustable QA1 shocks can be found on the rear set to 6, with 0 being the softest and 12 being the hardest. Up front, the suspension was left stock. Custom 1x2-inch-diameter subframe connectors were installed to tie the front and rear of the car together, thereby stiffening the structure. Polyurethane bushings reduce deflection in the rear suspension to improve launches on the dragstrip. Made from 13/4-inch diameter tubing, the custom chrome-moly six-point rollcage with swingouts keeps the driver protected and further stiffens the overall structure.
Once finished, Ken took his car to the track, and with a 4,020 pound race weight (3,770 without the driver) ran that all-time-low 9.77 e.t. and produced a 60-foot time of 1.401 on essentially stock suspension. His secret? "For my launch technique, I use the transbrake, leaving at 5-7 pounds of boost, depending upon track conditions, and shift at 6,500. The GTO goes through the traps at 6,400 rpm."
This seems to be the trick needed to get those 15x9 Bogarts rolling, without toasting the Mickey Thompson 275/50-15 ET Street Radials out back. In front, 15x4 Bogarts and M/T Sports-man 27x7.5x15 tires cut down rolling resistance. To fit the larger rubber under the rear of the Goat, the inner wheelhouse had to be clearanced in a few spots, and the outer wheelwell lip was rolled.
The performance of this package is quite impressive when you hear the numbers and even more so when you realize that the car is street driven. Note we said street driven, not street legal. Since Ken's '04 GTO is so new, it has a year before being emissions tested. So, until then, he's still able to get to the track under his own power. Regardless of how he gets there, the choices made in upgrading his Pontiac project have made this 9-second Poncho quite a drag--literally.