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2004 Pontiac GTO - Hybrid Hot Rod

A GTO With 434 Cubic Inches Of Environmentally Friendly Horsepower

Justin Cesler Aug 1, 2009
0908gmhtp_01_z 2004_pontiac_gto On_the_road 2/9

Car Feature 2004 Pontiac GTOFor many people, the word hybrid conjures up images of boring, silent, egg-shaped automobiles driven by environmentalists set on ruining everyone's fun. Some see them as a means to an end, a slightly boring car that gets them from point "A" to point "B" as efficiently as possible. Then, there are people like Roy and Laura Vincent. People who think a hybrid means a solid roller, 434-cubic-inch monster that drinks E85 through its gigantic 255cc ET Performance, six-bolt heads and expels all the noise through a set of 3.5-inch cutouts. Yes, these are our kind of people.

Roy and Laura bought this 2004 GTO brand new in January 2005. As time progressed, they both grew tired of the stock LS1 and decided it was time to build a car that was fast, driveable, and rock-solid reliable. If you are going to build something of this scale, you better start with good parts and even better people. For this, Roy and Laura turned to Vals Automotive of Round Lake Beach, Illinois, to design one of the most solid all-motor setups in the country. Starting with a new GMPP LSX block, Vals had Westech Automotive machine a 4.155 bore and stuff it with a set of -3cc Keith Black forged pistons wrapped in Total Seal rings. Callies was called upon to provide the forged connecting rods and Dragon Slayer forged crankshaft, complete with 4-inches of stroke. The entire motor is bolted together using only the finest ARP hardware and Cometic six-bolt head gaskets. A Moroso high-volume oil pump is in charge of keeping the Clevite bearings and rotating assembly lubricated, while a Meziere electric water pump and Ron Davis radiator keeps the coolant temperature under control.

Of course, all of these cubic inches mean nothing without airflow and again, for this, Roy and Laura turned to some of the best in the business. Starting with the conductor of this symphony, Roy had Comp Cams grind a humongous solid roller camshaft with over 0.700-inch lift (0.740 and 0.736-inches to be exact). Riding high atop these lobes are a set of Morel lifters and custom 3/8-inch pushrods. Together, these move a set of T&D 1.75:1 roller rockers, which are responsible for opening the massive valves housed inside the 255cc ETP aluminum cylinder heads. Sitting at 13:1 compression, Roy knew that the delivery of both air and fuel would be important, and like the rest of his build, he didn't skimp here either.

0908gmhtp_08_z 2004_pontiac_gto Front_grill 3/9

Starting under the front bumper, Vals Automotive built a huge `ram air' style scoop to pick up cold, fresh air. This air is then routed up a 4-inch tube to a custom filter box, which houses a K&N air filter. After getting cleaned, the air travels past a giant 100mm Nick Williams throttle body and into a custom-built Beck sheetmetal intake manifold. Knowing that he wanted to run E85, Roy uses eight 85-pound injectors, which are fed by twin, in-tank Walbro 255-lph fuel pumps. An adjustable Magnafuel regulator keeps everything in check on the pressure side, while an AEM low-impedance injector driver handles the stock computer. Tuning is done by Lance at Vals Automotive who has already made 590 rear-wheel horsepower with this GTO. Once compressed, the resulting mix of clean-burning E85 and hydrocarbon is routed through a set of port-matched Kooks 1 7/8-inch long-tube headers and into a custom, 3-inch mandrel bent exhaust system. Of course, if Roy is feeling extra obnoxious, he can open a set of 3.5-inch Quick Time Performance electric cutouts and let all of this noise come straight off the headers. With 13:1 compression and 434 cid, you better believe it wakes up the neighborhood.

With all this commotion, you need to make sure you're going somewhere and for this, Roy and Laura have surprisingly left most of the stock drivetrain in place. A stock rearend with 3.46 gears turns a set of BMR 300M 1 3/8-inch diameter rear axles and a pair of 275/40/17 Mickey Thompson drag radials wrapped over stock 17x8-inch GTO rear wheels. Meanwhile, the stock front wheel and tire combo helps the car corner and handle well on the street. Power comes from a Finish Line Transmission Level V 4L65E and Precision Industries 4,000-stall converter. A B&M cooler keeps the fluid temperature down but other than that, the GTO drivetrain is left untouched.

Inside, as well as outside, Roy and Laura stuck with a sleeper theme and added only what they thought helped take the GTO to the next level. With the much sought after SAP spoiler and grille package (along with an '05-06 hood), this GTO can stand out from the crowd but can also blend in just enough to sneak up on an unsuspecting Mustang. Moving to the cockpit, Aeroforce gauges are the only clue that anything is done, which really is a testament to how well-built the engine and drivetrain are. According to Roy "I have always wanted a car that took advantage of the modifications and speed capabilities of today's modern, computerized engines." When you don't have to constantly monitor every tiny piece of equipment and can relax while you drive, you really start to have some fun. In our eyes, this is what separates the old muscle cars from the new and is exactly the way Roy and Laura wanted it.



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Data File 2004 Pontiac GTO
Owner: Roy and Laura Vincent
Block: GMPP LSX, 434 cid
Compression ratio: 13.0:1
Heads: ET Performance 255cc, 2.10 intake, 1.57 exhaust valves
Cam: Comp Cams solid roller, 0.740/ 0.736-inch lift, 256/262 duration, 114 LSA
Pushrods: Custom 3/8-inch
Rocker arms: T&D, 1.75 ratio
Pistons: Keith Black, Forged
Rings: Total Seal
Crankshaft: Callies Dragon Slayer, forged
Rods: Callies, forged
Throttle body: Nick Williams 100mm
Fuel injectors: 85 lb/hr
Fuel pump: Twin Walbro 255-lph pumps
Ignition: Stock coil-on-plug
Engine management: Stock ECU, tuned by Lance of Vals Automotive
Exhaust system: Kooks 1 7/8-inch long-tube headers, QTP cutouts, 3-inch catback
Transmission: 4L65E, built by FLT
Torque converter: Precision Industries 4,000-stall
Driveshaft: Stock
Front suspension: Stock
Rear suspension: Stock
Rearend: Stock IRS, 3.46 gear, posi, BMR Fabrication axles
Brakes: Stock
Wheels: Stock 17x8
Front tires: BFG 245/45/17
Rear tires: M/T Drag Radial 275/40/17
Fuel octane: 100-105 (E85)
Current mileage: 22,000