Thanks to the noise-attenuation properties of the turbochargers, the STS kit obviates the need to run mufflers. It does, however, include this rear-section exhaust system, which eructed a deliciously nasty snarl through its 4-inch polished tips.
Shortly after this picture was taken, that nifty carbon-fiber air bridge blew apart during a dyno pull-the second such failure to occur in as many days. (The plastic stocker was the first victim.) Lovell plans to install an aluminum BBK bridge to prevent similar pyrotechnics in the future.
With all the turbo hardware socked away out back, the C5's engine bay stays cool and remarkably tidy. And aside from some minor trimming of the fenderwell liners, the factory bodywork escapes the installation process unscathed. Lovell needed around 12 hours to complete the job-it was one of the first production kits in the United States, after all-but feels confident he can slash that time by a few hours next time around.
Thomas' system also included this progressive methanol-injection kit, which came with a C5-specific harness and commanded an extra $499. With the kit in place, Lovell was able to dial in more boost without fear of detonation.
Low-Boost Setting:
With the twin Garretts puffing out a pump-gas-safe 6.5 psi, the otherwise-stock LS6 cooked up 525.8 hp and 458.8 lb-ft of torque on the Anti-Venom chassis dyno. That's comparable to what we'd expect from an intercooled supercharger system at the same boost level, and more than enough to propel the car into the low-11s with adequate traction. Factor in that impossible-to-quantify "twin-turbo" cachet, and the STS setup makes a compelling new addition to the C5 forced-induction market.
High-Boost Setting with Methanol Injection:
With the kit having already eclipsed the 525-rwhp mark, Lovell decided to nudge the absurdity meter even higher with the optional progressive methanol-injection kit. With the turbos now safely spooling out 9.6 psi of meth-chilled boost, output shot to an unconscionable 600.4 hp and 543 lb-ft at the rear wheels. With a little more tuning work, Lovell thinks the 650-rwhp mark is well within reach. Still need more? STS offers multiple turbo upgrades capable of supporting up to 1,500 hp.