When it was later decided that 2Fizzle would be taking on more of a drift role through our Need For Speed: Pro Street partnership (remember, you can still download this car from EA's Web site), we had to upgrade the open diff with a limited slip, so we opted for a mechanical NISMO 1.5-way LSD. Why is an LSD important for drifting? "Having an LSD is important because it enables you to have two wheels to propel the car forward as opposed to one wheel trying to propel you forward while the other one is being dragged around," says Benson Hsu, a bonafied Sileightymaniac (www.sileightymania.com), "It's like walking; you do much better with two working legs. If you were walking with one good leg and one dead leg you'd have to drag along, you'd run out of steam quickly. An LSD lets you walk with both legs, so to speak; you can drift and continue drifting as long as you're spinning the wheels. And if you have high grip tires, it will even let you accelerate as you speed. Not having an LSD will only let you break traction, but the length of your drift depends on how much inertia you have. Eventually it will die off." See, the pros know how an LSD benefits a drift setup and now you do, too.
The Real Ultimate Power
The last order of business for 2Fizzle was to pull some real power out of it. The only way to do that was to install the remaining HKS components, like the EVC EZ, A/F Knock Amp and Stage 2 valve train package (264 cams, valve springs and valves). A lot of people, including myself, were curious to see how much power my SR was going to produce, considering it was a full HKS build. Since this was a street car and the bottom end was going to be left stock, most guessed 300 hp on the conservative side; others felt 350 hp would be a piece of cake. Back at SR20Store, Marco Vargas tackled the job of installing the valve train pieces and right after was sent to Creative, where they custom-mounted the EVC EZ and A/F Knock Amp in the center armrest along with the HKS turbo timer in the center console. After these crucial electronics were installed, I decided to hit a Pro Dealer that had an in-house Dynojet and found comfort in trusting the people at SP Engineering, who graciously stepped in to offer its tuning expertise.
Tuning high-end Japanese sports cars and luxury exotics like the Lamborghini is SP's specialty; they thrive on big power and are not afraid to the push an engine's limitations. With my SR20 in the hands of a master tech, Hirofumi Kondo established a baseline of the untuned setup by pulling 312.4 hp with 254 lb-ft at 1.1-bar (16 psi), a HUGE jump over the last dyno session that resulted in 180 hp without any valvetrain mods and the GT-RS alone. But since the original base map was created at Dynamic Autosports, SP had to wipe the V-Pro clean (since pro dealers lock the V-Pro with a password to protect their maps) and start fresh. After creating a new base map, Hiro could finally turn the boost up to see what the SR could really do. With a fresh set of NGK V-Power A-8 spark plugs dropped in, the long process began-309 hp came first, not far off the original 312 hp from an untuned base map, then something bad happened: fuel leakage from the HKS fuel rail. Hiro traced the leak to the fuel injector grommets that had popped off from cylinders one and four, but the two dyno runs following showed that as the power hit 325, the grommets would pop back out again. Not only was this causing fuel to leak, but the boost level was also highly unstable, the likely result of a boost leak. This was because the fuel rail's aluminum spacers fit loosely even when tightened all the way. Hiro quickly came up with a solution on the fly: shave the spacers about 3 mm, which gave a nice, tight fit and stabilized the boost at 1.3 bar. With the SR finally holding steady, horsepower figures increased again to 337.8 hp with 294.9 lb-ft and in the end, after nine hours of dyno time, we called it quits when Hiro nailed 339.4 hp with 295.8 lb-ft! Patient tuning in our case worked out great and equaled great success!