Strike every book, magazine and parking-lot bench racing session in the world -- probably no innovation in the history of man has taught America's youth more about the intricacies and art of tuning a car than the Gran Turismo game series. In fact, to some people, the racing itself is secondary to the tuning aspect and game physics, which have gotten better and more intricate with every iteration. Can you learn to tune a real Acura RSX -- or any other car -- for drag racing by playing with the JDM Integra Type R in Gran Turismo 5? Maybe, maybe not -- but you can certainly learn a lot about the physics of race tuning, either way.
In the Gran Turismo 5 video game, upgrading the engine is just a matter of throwing every staged upgrade at it. In the game, that will get you up to about 398 to 400 horsepower at about 9,700 rpm, which is achievable with the RSX -- aka Integra -- K20 engine. That 400 horsepower has been achieved on a regular basis without a turbo. But the stock bottom end and rods won't go near that rpm. You're going to need to replace the entire bottom end with forged internals, and the head and main bolts are notoriously weak. These should be the first thing you replace on any serious build, and spend about $15,000 on the engine total. Without spending about $15,000 on the engine, the bottom end is good to about 250 to 300 naturally aspirated horsepower. That's about the limit you'll want to go for an all-motor car engine; any more than 300 horses on this engine will make it a nightmare to drive on the street.
Honda as a company has an enduring hatred for turbocharged road cars, preferring the all-motor route whenever possible. That may be why turbochargers aren't even an option for this car in GT5. In the real world, though, a turbo is going to get you where you want to go a lot cheaper and more reliably, and will get you to the game's 400-horsepower mark without making your car an intolerable, bucking monster on the street. The K20 has the potential for as much power as any front-wheel-drive car can handle. Import Tuner Magazine once built one with Skunk2 racing, and it made over 700 horsepower at the crank. A 400-horse turbo engine will not only be more civil on the street, but using an electronic boost controller, you can custom-tune your setup to deliver the maximum amount of power to the wheels in the appropriate gears. Speaking of gears, the hot drag setup for an NA car in GT5 is 4.79-first, 3.955- second, 3.214- third, 2.62- fourth, 2.155- fifth, 1.837- sixth and 3.0-to-1 final drive.
Gran Turismo has probably done more to advance the understanding of chassis tuning and physics than anything in history, and chassis tuning the Integra in this game is an object lesson in that. For a front-drive drag car, chassis tuning is all about putting weight on the front tires. In the game, start by adjust ride height with a negative 25 setting on the front and a plus 40 setting on the rear. This "rake" is exactly what you want in the real world, since it gives you an advantage by putting weight over the front tires. Set the front shocks with a "1" extension and a "10" compression, and do the opposite for the rear shocks. You want a very stiff, 15.5 rear spring rate, and a much softer 2.5 front spring rate. Just as in the real world, this will keep the nose of the car down, and keep weight from excessively transferring to the rear under power. You'll want the biggest and softest-compound front tires, and the hardest and narrowest rear tires available.
In the real world, you'll want the front tires as straight-up and straight-ahead as possible; the game's 0 degrees front camber and mild 0.4 degrees positive toe reflect that. For front-drive cars, the rear axle's only job is to keep the car pointed straight; the game's 4 degrees of camber and negative 1 degree of rear toe will keep the rear from stepping out and unloading one of the front tires. For drag racing, you'll want a true locking differential. In the real world, that means an air locker or spool to split power evenly at all times. In the game, that's a two-way limited slip set to lock at 10 initial, 40 acceleration sensitivity and 20 deceleration sensitivity. Brake balance in the game and in the real world should be about even, 5 and 5 front and rear. The extreme difference in tire size and suspension settings will already bias braking toward the front, so an even bias setting will restore something close to the front-biased braking dynamic you'd normally experience.
In the game, a Stage 3 weight reduction will get you down to about 1,130 kg, or about 2,500 pounds. Technically, stripping the real car's interior out and taking other basic weight-saving measures could easily get you down that far, since a manual transmission car only weighs about 2,720 pounds. However, the game's Stage 3 weight program does accurately reflect reality for a hardcore race car, since in the real world you'll need a full roll cage and plenty of subframe and strut tower reinforcement to meet NHRA E.T. safety requirements, and keep this unibody chassis from twisting in half. In the game, you'll want to add about 130 kg -- 286 pounds -- of ballast to front for a 65-35 front-rear weight distribution. That's approximately true in the real world, too, with one caveat: Since the entire car aft of the front wheels acts essentially like a giant wheelie bar, you'll want to put your ballast as far to the front as possible -- and lower than the axle centerline -- to keep its weight from transferring to the rear under acceleration. If you're thinking of a lead-shot-filled steel pipe behind the lower-lip of the front bumper, then you're thinking in the right direction.
