Got the 4.235 installed in my 2002 NSX T

[1BADNSX]

So let me get this straight. Because a computer simulation that does not take into account any mods, a guy (SJS) who says it cant be because he broke out his slide ruler and it did not add up, and nsxtacy saying that my car just hooked better one night compared to the next, I have managed to inturpit that my NSX has done the imposible. WOW! I am glad I did the R/P now.
SJS, nsxtacy please tell me this, did my IHE and light other mods get me down to the 4.07 0-60 and 12.4 in the 1/4?

Your car obviously is very good in the ¼ mile, nobody is arguing that, but I think you are taking it personal that they are questioning how you achieved the result. To answer your question and give you an idea of how weight reduction and power addition affects 0-60 and ¼ mile, here are some results for stock 91 NSX. The net affect would be lower for your car because it is already faster.

- 100 pound weight reduction lowers 0-60 times by 0.16 sec and ¼ mile by 0.16 sec

- Adding 15 HP lowers 0-60 times by 0.31 sec and ¼ mile by 0.32 sec

- 4.23 R&P by itself lowers 0-60 times by 0.13 sec and ¼ mile by 0.10 sec

Attached is the graph I promised. This shows the shift points and how a lowered gear R&P doesn’t always improve acceleration.

Bob

 

[nsxtasy]

Just in case Bob's point is not clear...

Adding a 4.235 R&P to a stock '91 coupe reduces 1/4 mile times by 0.10 second. Adding a 4.235 R&P to a stock '97+ coupe reduces 1/4 mile times by 0.07 second.

Adding a 4.235 R&P to a modded car is going to improve 1/4 mile times by less than either of those two figures, not more.

There are lots of reasons why the 1/4 mile times for your various runs may have improved by 0.4 second - variations in driver inputs, variations in environmental conditions, etc. It is physically impossible for the additional acceleration provided by the 4.235 to account for more than 25 percent of that improvement.

You are quoting your best times here. Perhaps you were having a better day when your times went down to 12.4 seconds, and had one particularly good run. I am betting that your run-to-run differences are significant - that when you did 12.4 seconds, you also had some runs with 12.6 and 12.8 seconds. That's normal, because of differences in your inputs and response times, and in getting the tires to hook up. Your runs weren't all exactly 12.8 seconds and they didn't suddenly all become exactly 12.4 seconds when you changed the R&P, right? The same differences you experience from one run to another with either setup can happen with your tests from one setup to another. Just because you have a "best" on a particular day for a particular run, doesn't mean that that result is a precise measurement of the capability of your car.

 

[AJKS]

Just in case Bob's point is not clear...

Adding a 4.235 R&P to a stock '91 coupe reduces 1/4 mile times by 0.10 second. Adding a 4.235 R&P to a stock '97+ coupe reduces 1/4 mile times by 0.07 second.

Adding a 4.235 R&P to a modded car is going to improve 1/4 mile times by less than either of those two figures, not more.

There are lots of reasons why the 1/4 mile times for your various runs may have improved by 0.4 second - variations in driver inputs, variations in environmental conditions, etc. It is physically impossible for the additional acceleration provided by the 4.235 to account for more than 25 percent of that improvement.

You are quoting your best times here. Perhaps you were having a better day when your times went down to 12.4 seconds, and had one particularly good run. I am betting that your run-to-run differences are significant - that when you did 12.4 seconds, you also had some runs with 12.6 and 12.8 seconds. That's normal, because of differences in your inputs and response times, and in getting the tires to hook up. Your runs weren't all exactly 12.8 seconds and they didn't suddenly all become exactly 12.4 seconds when you changed the R&P, right? The same differences you experience from one run to another with either setup can happen with your tests from one setup to another. Just because you have a "best" on a particular day for a particular run, doesn't mean that that result is a precise measurement of the capability of your car.

I disagree. The NSX is very consistent 12.8's for over 25 runs before 4.235's. After 4.235's consistent 12.4, 12.5's a 12.6 because spun a bit and got a 2.xx 60 ft not a 1.8x-1.9x (my normal).
The 4.235 was the only change. Yes, that night the atmosphere was not exactly like it was 2 months earlier when I ran 12.8's. So do we all agree that from one night to the next my NSX ran a best 12.85 and 12.47 a difference of .38? I have the time slips to prove it so I am going with a yes. So lets for a minute say the R/P improved my 1/4 mile time by .1-.2 are you all going to say that my inconsistent driving netted me the other .18-.28 improvement? If you say yes, I will argue this point, I have been racing for 17+ years and I think I have it down. I know how to launch the car, I know how and when to shift the car. There is not much more to it than consistent driving. This is my 4 NSX I and I know how to drive them.
The only little difference is the outside air temp, about 10-15 degrees less from the 12.8's to the 12.4's. So you can go to the HP calculator and see how much more HP is produced with a 10 degree variance in air temp. I am sure it will not be more than 2-3HP. A 2-3hp difference is not enough to give a .10 difference in 1/4 mile times.

 

[sjs]

Well it's clear that we are all spinning our wheels here. AJKS firmly beleives what he is saying and we are equally positive that it simply is not possible. He feels his time slips are proof where as we insist that they are at best flawed evidence fraught with potential variables and prove only that his car is very fast and he knows how to drive the wheels off of it. Personally I don't really care other than to caution others against assuming that they will see similar improvements.

One last point since temperature has been mentioned several times. Ambient air temp is not necessarily the same as inlet temp when you sit in line waiting for your turn, especially on a sunny day. And of course there are other environmental factors, some of which are somewhat compensated for by the ECU but may still cause differences.