Originally posted by SNDSOUL:
There is an NSX owner in our area that has the gears and 4:55's. His car makes a very annoying sound from the gearbox and the combo of the gears and the r/p combined with the Comptech SC on his car causes the car to hit redline too quickly in my opinion. Shifting gears is slowing down. He also claims to only be able to reach about 150 mph. That is a definent disadvantage IMO. I have driven his car several times, back to back with my own(with the same mods,but 4:23 and nitrous instead of SC)and my set up seems much more natural and linear. Not to mention I outrun him in the 1/4 easily. We have never raced on the interstate, but I can tell you that I have done 170 many times and if he cant break 150, then there's no chance there either. I believe Dave was looking for the most streetable set up without compromising top end or drivability. Having to shift 4 times before 85 mph would get on my nerves in a hurry.
I have heard people say that there was a problem with noise with the 4.55 R&P at one point, but that this has since been corrected.
With a stock '91-96 NSX, if you could redline it in fifth gear, it would be going 186 mph. You can't, because it's drag limited; the stock power is only able to overcome drag enough to accelerate up to 168 mph, which is short of redline.
If you can redline an NSX with a 4.55 R&P in fifth, it should be going 166 mph. It's possible that it might not have enough torque to go that fast because the torque curve drops somewhat above its peak around 6500 RPM. However, with a supercharger, I would be rather surprised if it couldn't get up to the 166 mph redline, given a long enough stretch of road.
With the short gears and 4.55 R&P, third gear is good up to 90 mph, so it's at 90 mph that you would be making your third shift, not your fourth shift. With the stock gears, this happens at 114 mph.
According to Bob Butler's figures, a car with the 4.55 R&P should be about 0.1 second
quicker in the 1/4 mile than with the 4.235 R&P, with short gears or with stock gears. Those figures assume stock power, but I would think the advantage of the 4.55 would still hold with modded cars if the performance improvement ("area under the curve") was equivalent on both cars.
There are other disadvantages to the 4.55 R&P, such as poorer mileage and higher revs on the highway in top gear, but most of the differences are relatively minor. The biggest downside to the gearing mods is that the actual measurable performance improvement is relatively minor in relationship to the amount of money spent. The upside, of course, is that they
are quicker nonetheless, and they also add a perception of greater acceleration because you reach redline faster, even though the difference in reaching a given road speed is not that dramatic.
[This message has been edited by nsxtasy (edited 06 January 2003).]
