2004 Pontiac GTO - Sports Car Solution

Pontiac's '04 GTO was sleeper material from the instant it hit the streets. Visually, it had the most demur look of the new-age Goats with a flat hood and dual exhaust exiting on one side in the rear. What it lacked in visual brawn it made up for in underhood grunt...to a point. With 350 hp on tap, the LS1 had a great battle cry and the aftermarket answered the call with plenty of performance goodies to extract serious power from the LS-series engines.

Knowing this all too well, the understated look of the '04 didn't prevent Ronnie Ferrell from purchasing this Pulse Red model in October of 2006. The 35-year-old manager for a medical device company from Winter Garden, Florida, had to replace his '00 Corvette with something that could fit his two sons, Dominic and Andrew. "Ultimately, it was the GTO's comfort, build quality, substance, and room for four that won me over," he says.

His limited-production W40-equipped Goat is special among '04s with paint code 129L and trim code 81I, which were only assigned to 512 manual transmission cars and 282 automatics that year. It was supposed to be the 40th Anniversary GTO package, but exterior and interior color changes were as far as it got. There were no performance enhancements or special badging.

He was used to Corvette performance, and the new GTO didn't deliver the sports-car feel Ronnie was looking for at first, so he tapped into the flourishing late-model Goat aftermarket to accommodate his need for more performance.

Power Plan
After he grenaded his engine on the chassis dyno, Ronnie decided he would take his GTO beyond the regular bolt-ons, and power it with an engine that would hold all the boost he could throw at it. Since the LS1 block was cracked, an LQ9 iron block was used. Its cast-iron construction is more suited to the increased cylinder pressure seen under boost, and is a cost-effective alternative to a comparable aluminum block of similar bore. Tom Tiberio of Tiberio Performance in Tampa is notorious for his late-model GTO projects, and was employed for the task of building the engine.

Forged Diamond pistons with a 13.7cc dish lower the compression to 9.0:1 and feature Total Seal rings. Callies Compstar H-beam rods are connected to the factory 3.622-inch stroke LS1 crankshaft. Combined with the LQ9's 4.00-inch bore, this former 5.7L GTO is now a full 6.0 liters and 364 cubic inches. A Comp Cams hydraulic camshaft rated at 234/232-degrees duration and 0.598/0.595-inch lift actuates the factory rocker arms to control the valves by way of a set of Manley 5/16x7.400 pushrods and Patriot Gold Dual springs. Jeremy Formato Tuning & Porting of Tampa ported a set of 243-casting LS6 cylinder heads for Ronnie's application, which feature larger Ferrea 2.04/1.57-inch stainless valves. Keeping things lubricated is an SLP high-flow oil pump operating from the stock oil pan and with a stock windage tray setup.

Factory exhaust manifolds were ported to keep up with the increased airflow and feed into 2.5-inch JBA catless mids and an STS 2.5-inch crossover pipe, which leads into a 3-inch I-pipe back to the Dynomax muffler and turbo. Yes, you read that correctly-turbo. The unconventional location of the STS rear-mounted turbo system provides lower air intake temps, underhood temps are reduced, and the kit is easier to install than with conventional turbo placement. Ronnie upgraded from the base T04E 60-1 Garrett Turbo to a Precision PT76GTS T4 flange ceramic ball-bearing unit. It uses a Tial 44mm wastegate with a Tial 50mm blow-off valve. Together, they deliver 20 psi and are regulated by a Turbosmart e-Boost2 boost controller. A single-row STS front-mount intercooler helps to lower the intake temperatures as it flows into a PTM 90mm throttle body and custom intake elbow mounted to an Edelbrock Victor Jr. manifold.