In the same manner as my post reviewing the GT2 cars, earlier today I was tuning all of the Japanese GT500 class cars to 875 PI for a friend and decided to write my opinion on each (and driving them all back to back actually produced some surprising opinions about certain ones). Unlike the GT2 cars, my opinions on these cars were formulated from their tuned form (at R2 875 class) using max tire width, race brakes, and stage 1 restrictor removal for all of them.
If you had asked me my personal favorite GT500 car to drive prior to today’s adventure, this would have been my selection. I have the most time spent driving/tuning this one and it’s the one I previously held most of my fast laps with. That said, it was ironically the slowest of the group (save for the new model GT-R but read the review on it below to understand why). Despite the mid-engine layout’s benefits, the one thing I really disliked about the NSX was the engine’s peaky powerband combined with twin turbos. It made for an often unpredictable as unstable car coming out of corners; no matter how easily I rolled into the throttle, if it was over 6500rpm and the turbos spooked up it had better be pointed straight or it wanted to do donuts (extensive LSD accel tuning got it to a minimum but did not entirely alleviate the issue and it was still prone to sudden snap-oversteer when the turbos started feeding positive pressure back to the intake). I like the car overall, of the road cars the NSX is tied with the R34 Skyline GT-R as my favorite in real life, it was just never quite as good as the others once I got them dialed in. Don’t let that take away from the NSX, though. All of the cars had fast laps within 1 second of each other on Laguna Seca where I was tuning them.
The stock gearing was atrocious at best. I opted for the 1st-5th from the stock '97+ NSX 6-speed (3.07/1.96/1.43/1.12/0.91) and shortened the 0.72 6th to 0.77 with either a 4.44 or 4.62 final depending on track. It was effective at keeping the car from dropping below it’s defined powerband. The turbos help keep the peaky nature of this motor from becoming too apparent, but the NSX V6 still lives up to its reputation and frantic shifting to keeping it screaming towards the redline is necessary.
The fastest overall lap times belong to the Supra. I have few complaints about this car beyond it being a bit more prone to understeer than the others, nothing a little tuning can’t fix but worth mentioning nonetheless. The overall feel of the car is very different from the road-going MKIV Supra due primarily to the 2JZ 3.0L twin turbo inline-6 being replaced with a 4.5L DOHC V8 that the Super GT500 class eventually began to require in all cars. Compared to the other cars it has a torquey nature and the powerband feels a bit lower in the rev range than the others.
The car responded well to numerous gearing setups, although I highly recommend setting them quite a bit closer than the stock spacing for best performance. I personally opted for a Quaife 2.72/1.99/1.52/1.21/1.00/0.86 setup with a 3.77 final (I tried a 4.08 at times but even on shorter tracks the car seemed happier with the longer 3.77 rear gear).
I race in cockpit and this car had me wishing for the Panoz Abruzzi back! The visibility is such a joke I went off nearly every corner on my first lap of Laguna Seca and sent it back to my friend stock saying he can tune the stupid thing himself. You want an unbiased review of this car? Write it yourself. The dash display needs to include a sonar display so I know where other cars are.
Nissan R34 Skyline:
Possibly the greatest of the iconic Skyline dynasty that Nissan (and formerly Prince) have established as nothing short of a legend in Japanese GT racing. From the army of 4-door sedans in the '60s that tailgates a Porsche prototype in the 2nd annual Japanese Grand Prix (after many hours of hard racing the Porsche limped across in 1st place with Skylines sweeping 2nd-6th places all less than 30 seconds behind that German prototype racer) to the famed 50 wins to the warning the nickname of “Godzilla” through its dominance, the Skyline has long been one of the lost formidable GT cars Japan has ever seen.
The twin turbo 6-cylinder lacks the snap-oversteer of the NSX and has a broader low-end torque curve that helps it rocket out of corners. This car’a lap times were second only to that V8 Supra and the JGTC-era R34 Skyline should be considered one of the most serious contenders in this class when tuned correctly.
The gearing setup is actually the stock production R34 6-speed which is clearly not going to get the job done in a racecar of this caliber. I used a PPG 3.20/2.19/1.56/1.20/1.00/0.83 gear set with the factory road car’s 3.55 final drive ratio for the best results. One thing worth noting is the JGTC R34 has by far some of the largest instrument displays of any racecar and even though it lacks some features (lap count, position, etc) I find its very large displays to be some of my favorite.
At 8500rpm the Lexus V8 had the highest-revving engine of the bunch and was notably more peaky than the Supra and R34 Skyline, though that’s not necessarily a bad thing once you get the gears set correctly. In fact, the Lexus was the most surprising to me because once it was tuned right it was by far the most neutrally balanced of all the Super GT500 cars I drove. I wouldn’t hesitate to call it my favorite to drive (best lap time was less than 0.050 seconds behind the Skyline and the SC430 was the most consistent of all). It was the one it had driven the least and now I very much regret that decision as it quickly proved to me that it should have been my favorite over the NSX all along. I feel like the fact that it is a Lexus SC430 hurts the overall appeal as it is not a name generally thought to be a great performer. Concerning the road car, calling the performance lackluster would be generous (this is coming from someone who formerly worked for Lexus and logged many hours behind the wheel of an SC430 not merely someone who has never driven it echoing Top Gear’s opinion as it being one of the worst “performance” 2-sweaters ever made); it truly is that bad in road-going form. However, it undergoes a total Dr Jekyll and Mr Hyde transformation in GT500 racing form; it should not be overlooked and if I were to spend my credits on any Super GT500 car I’d but the SC430 first every time.
The gearing is a bit of a departure from what I’ve used with the other cars, the SC430 ended up with a more high-winding final and a double overdrive (something I normally will only use on large-displacement low-revving racecars like a Corvette or Aston Martin DBR9). I used a 2.40/1.66/1.24/1.00/0.87/0.77 set with the default 4.45 final and found that worked best of the dozen or so different setups I experimented with.