Six years ago I set out on a quest to build a car that was fast, could go unnoticed by most cops and, more importantly, was the complete opposite of anything I drove before it: rear-wheel drive. I found that when I picked up a '91 Nissan 240SX for roughly $5K-it had a SR20DET already. You've seen it in various stages of completion, from its humble beginnings of quality HKS bolt-ons and its conversion to five-lug suspension, leading all the way up to this, the grand finale where I show you the last of the parts, the initial stages of tuning and the big sendoff where the damn thing finally made power. It's a tech build-up long overdue, but it's DONE. Stick a freaking fork in it.
Baseline Tuning the GT-RS
At the point where we last left off, in a galaxy far, far away, we had just finished installing the HKS GT-RS turbo to our SR20DET with stock internals at SR20Store. From there, the car was moved down to Dynamic Autosports, where an HKS F-Con V-Pro engine management was installed. I picked a V-Pro because of its tuning flexibility and it's cool because it gives you lots of options, especially if you're the kind of person who wants to mix things up with tuning for drifting or Super Lap Battle-it's really up to you and your tuner. This standalone unit plugs in easily like an ECU through HKS' plug-and-play harness (custom wiring harnesses are available by request through HKS), which is great since you don't have to hack up your original wiring harness. It's equipped with a quick processor and is set to a 32x32 resolution for fuel and timing maps. Sounds complicated, but it's really tits.
The V-Pro is not for the faint of heart. It's a serious computer that only certified HKS Pro Dealers can tune, which is why I turned to Dynamic. Hooked up to their Mustang dyno, their tuner, Jeff, began a simple base map for the car to operate on safely since neither an EVC nor an A/F Knock Amp had been installed and both are a must for any tuning. With limited tuning options, he mirrored a near "stock"-like map, no increased boost to prevent damaging the engine; figures at that point were 180 hp and 173 lb-ft. Keep in mind, however, that a Mustang dyno tends to read anywhere from 10- to 20-percent lower than a Dynojet and Jeff explains it as "like driving on the road with a proper load." Factoring in those percentage losses, the car could've realistically been putting out power in the range of 198 to 216 hp. I took 2Fizzle home somewhat disappointed because I couldn't really go boost happy-well, I couldn't really boost at all. I figured that would be a good time to work on other parts of the car until the electronics were wired up.
Mynismo.Com Lends A Helping Hand
I've discovered that the key to making the 240 a lot of fun to drive is to have the right suspension in place. It takes more than just slamming it on a set of coilovers to do it justice, although it always looks like slamming it is the best way to go. You may recall last month's discussion on the 240 as one of the top tuner cars and what Eric Hsu had to say about setting up a 240 right: "The car benefits big time with a good coilover suspension along with good suspension components and alignment. To properly slam a 240, you must use roll center correction kits and bumpsteer correction kits, and physically mount the rear subframe higher up in the chassis with aluminum subframe bushings or heavy fabrication." That's a serious way to approach suspension on a 240. I didn't go as extreme, simply because it was going to be primarily street driven, but I looked to Andy Kim at MyNismo.com to help me out with a set of rear upper control arms from Battle Version and a NISMO Power Brace. The Battle Version arms are used to help adjust camber since it's usually thrown way out of line once the car's lowered; other options would've been to add forward and toe links to the mix. The NISMO Power Brace's function is to work with the Peak Performance front tension rods and minimizes movement of these rods while cornering, giving you much better handling.
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!
Safety First, Kids
No drift car would be complete without one of the most important pieces of safety equipment: a rollcage. For those aiming to compete at a more professional or competitive level, we'd suggest finding a fabricator who can weld you a cage according to whichever sanctioning body's rules you decide to enter under, but for the amateur or beginning drifter, a bolt-in cage is a good start. With this in mind, we contacted Cusco USA for a six-point rollcage, although due to spacing issues, left the front two point bars out to prevent obstruction of the front seats. Also, this particular cage is meant for a RHD car as you'll see the cross bar going the opposite direction, but Cusco does offer LHD applications. Since 2Fizzle will most likely NOT see a lot of competitive drifting, we'll leave it as is until it must be upgraded to a legal spec cage.