Tuned Twin-Turbo Pontiac GTO Throws Down on Dyno
A couple of simple tweaks are all this boosted Pontiac GTO needs to achieve some pretty impressive (and reliable) numbers!
Tuning is a magical art, one that only a select few have mastered. One of those wizards of unlocking horsepower is most certainly YouTuber Sloppy Mechanics and resident LS1 Tech admin denmah. And while he’s admittedly not a huge fan of working on the much-beloved Pontiac GTO, he makes an exception here for a friend of a friend. This particular car has been twin-turbo’d almost since day one, receiving an infusion of boost with a mere 2,000 miles on the odometer.
Unlike many twin-turbo’d LS-powered cars, the goal here isn’t to make maximum power at all costs. The owner routinely drives his car on trips, including Hot Rod’s Power Tour. So he understandably wants something powerful yet reliable. But it doesn’t take much to overwhelm the rear tires, which quickly become the weak link in this setup.
In addition to the APS twin-turbo kit, this ’04 Pontiac GTO sports a few additional goodies. They include a Walbro 450 fuel pump, 80 lb injectors, a Lil’ Johns Motor Sports cam, a twin-disc clutch, and BTR springs. And thankfully, the older ECU that our resident tuner is much more comfortable working with. Unfortunately, 40 degree weather and hard-as-glass tires cause some issues, but not enough to keep this GTO from hitting some solid numbers.
With a couple of adjustments, the boosted GTO hits 526 hp at the wheels with no problem. And that’s with a mere 6 lbs of boost, with conservative fuel and timing! And as our host notes, “you could beat the living trash out of it” with this kind of tune. Plus, when things get cranked up higher, it just spins the wheels endlessly. Even with the small turbos, he predicts this thing is capable of 700-800 hp. Now it just needs a good set of sticky drag radials!
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