Got the 4.235 installed in my 2002 NSX T

[AJKS]

For all of you non believers out there here is the theory behind the .4 second improvement 0-60 and 1/4 mile. First this is not that big of a deal. A stock 2002 NSX R runs 0-60 in 4.4 seconds and 12.8 in the 1/4 mile. My 02 NSX with weight reduction (2940), IHE, Comptech Power Grip II (I only mention this item specifically because of its light weight advantage and benefit of mass flywheel weight reduction that the NSX R does not have) and some hard driving, with lots of runs has got to 12.8 1/4 and 4.4 0-60. Second, I go out and put 4.235 gears in and my NSX and best is 0-60 in 4.07 and 12.4 in the 1/4 mile. I bet if you do all the things I have done to my 02 NSX to the NSX R you would have a sub 4 second 0-60 and a 12.3 second 1/4 mile. The NSX R still has a 75 pound less weight advantage, after all my weight saving measures, with a full tank of gas over my NSX. So a combination of things got my NSX to the time it runs today. Third, can you just go out and get a 2002 NSX and throw some 4.235 gears in and run .4 second faster 0-60 and 1/4 mile. I would say no way in HELL. It took lots of work and right part combination to get my NSX as fast as it is and it was in no way cheap.
Now lets talk basic facts. R/P improvement is seen mostly in the 1st and 2nd gear range. Well 0-60 is first and second, THIS IS WHERE IT COUNTS....... You just so happen to get the benefits in the 1/4 because they were done early on. DRAG RACE secret number XXX BE at the end of the 1/4 right at the top of what ever gear your in. Works the same for 0-60. You end up at almost the top of 2nd 0-60 and at the top of 4th in the 1/4 after the gear swap. With stock gears the NSX still has about 1500 RPM to go in 2nd @ 60 and 2000-1500 rpm to go at the end of the 1/4. I bet if you took 2 NSX's with all things being equal, except the R/P and had both timed from the 2nd gear up shift to 3rd, through the rest of the 1/4 mile you would find that the 4.235 geared NSX isnot that that much faster than the one with stock gears. So the improvements are minimal in 3rd and 4th. I did not see much improvement in the MPH through the 1/4 mile just .8 MPH. Just a side note, I have seen .3 1/4 mile improvement on my 1990 LX 5.0 Coupe Mustang with a 3.55 to a 3.73 R/P swap and .6 from the 3.55 to a 4.10 R/P swap. Is there not one old school drag racer out there that can back me up here????? I have been racing for 17 years, mostly drag racing. I have a bit more experience than some of the Gents on PRIME when it comes to the 1/4 mile. I have had 4 NSX's and have made all of them run in the 12's in 1/4 with no nitrous. This one is the first in the 11's. I am surprised no one has given me grief about the 11.6 pass @ 120 with only a 100 shot of Nitrous. Hell, that pass was pre 4.235 gears. I cannot wait to see what it runs with some good tires (285-30-18 cup tires), 70 more pounds of weight reduction, and the 4.235 gears, on the Bottle.
Come on you guys we are not talking rocket science here just good old fashioned drag racing tricks that have been around for years.

 

[4AU4LIFE]

AJKS,

What would you assume a completely stock 2002/2003 NSX will do in the 0-60mph and 1/4th?

4.7-4.8 0-60 and 12.9-13.0 1/4 mile

Not quite true. Although there are differences from car to car of course.
According to the November issue of R&T
Acura NSX tested 3-02 0-60 5.0sec---1/4 [email protected].
And I'm sure they were 'driving like they stole it'. So you can draw what you want from these numbers.
AJKS,
How much weight does the audio system in your car add?

 

[NetViper]

Not quite true. Although there are differences from car to car of course.
According to the November issue of R&T
Acura NSX tested 3-02 0-60 5.0sec---1/4 [email protected].
And I'm sure they were 'driving like they stole it'. So you can draw what you want from these numbers.
AJKS,
How much weight does the audio system in your car add?

R&T also said those numbers may be a little off from their normal numbers because they were not testing at the same location as normal.

 

[4AU4LIFE]

R&T also said those numbers may be a little off from their normal numbers because they were not testing at the same location as normal

I didn't see that in the magazine?
The listing has a footnote that states
'also in 2003 annual'.

 

[nsxtasy]

R/P improvement is seen mostly in the 1st and 2nd gear range.

Actually, changing the R&P results in an improvement in every gear, but also results in a degradation at certain speeds - namely, those where the R&P requires that you're in a higher gear. This negates some of the advantage of the R&P. In general, you can expect an overall improvement in 0-60 but an overall degradation at speeds over 60 mph.

Here are figures that Bob Butler has calculated for a bone stock '97+ in various configurations:

'97+ six-speed NSX Coupe with stock R&P
0-60: 4.79 seconds
60-150: 27.45 seconds
1/4 mile: 13.24 seconds

'97+ six-speed NSX Coupe with 4.55 R&P
0-60: 4.47 seconds
60-150: 28.87 seconds
1/4 mile: 13.06 seconds

'97+ six-speed NSX-T with stock R&P
0-60: 4.93 seconds
60-150: 28.28 seconds
1/4 mile: 13.39 seconds

'97+ six-speed NSX-T with 4.55 R&P
0-60: 4.60 seconds
60-150: 29.74 seconds
1/4 mile: 13.20 seconds

I would expect the figures for the 4.235 R&P to be somewhere in between those of the stock R&P and the 4.55. Based on these calculations, it is simply unrealistic to expect gain of 0.4 seconds in 1/4 mile times due solely to a 4.235 R&P, and any differences of this magnitude are likely due to other sources (variances in driver technique from run to run being one likely culprit). Perhaps Bob can run the 4.235 through his model to calculate the figures for this R&P on a '97+ six-speed.

For those with the older five-speeds, here are some more figures to show the impact of changing the R&P on an otherwise bone stock car:

'91-94 five-speed NSX Coupe with stock R&P
0-60: 5.31 seconds
60-150: 32.47 seconds
1/4 mile: 13.67 seconds

'91-94 five-speed NSX Coupe with 4.235 R&P
0-60: 5.18 seconds
60-150: 33.08 seconds
1/4 mile: 13.57 seconds

'91-94 five-speed NSX Coupe with 4.55 R&P
0-60: 4.98 seconds
60-150: 32.04 seconds
1/4 mile: 13.43 seconds

 

[AJKS]

AJKS,
How much weight does the audio system in your car add? [/B][/QUOTE]

ZERO. I have a Panasonic DVD/CD/TV/AM,FM all in one, in dash unit with a small brain under the pax seat. I have used all the factory speakers. Good enough sound for me. I have also taken out the factory CD changer with cradle. If you add the new stuff and minus the old I think I saved 1 pound or so.

 

[4AU4LIFE]

AJKS,
How much weight does the audio system in your car add?

ZERO. I have a Panasonic DVD/CD/TV/AM,FM all in one, in dash unit with a small brain under the pax seat. I have used all the factory speakers. Good enough sound for me. I have also taken out the factory CD changer with cradle. If you add the new stuff and minus the old I think I saved 1 pound or so. [/B][/QUOTE]
Smart ideas. Just listen to the engine's music anyway right.

 

[sjs]

nsxtasy has already hit most of the points but I really must add to it.

Your key "facts" are anything but that. For example, as nsxtasy said an R&P is obviously across all gears. In terms of your 1/4 mile time it is also probably more important above 60 mph than below it. Why? Because if you really are doing 0-60 in 4.0 then you are spending more than twice that much time accelerating the rest of the way down the ¼ and the lower ratio is working for you all the way. Sure, you may benefit out of the hole if your car doesn't have guts to spin the tires though 1st gear, but then it's just numbers from there on up. So if changing the R&P gains you .4 seconds 0-60 but nothing more through the 1/4, despite the same number of shifts in each range, then either you aren't driving it properly or something else is very wrong.

But the bottom line that I tried to be tactful about previously is that .4 improvement in the 1/4 from just the R&P is improbable at best, and .4 off your 0-60 from just that mod is quite simply impossible. You can scream "facts" in upper case all you want, but your credibility is dwindling rapidly.

 

[AJKS]

nsxtasy has already hit most of the points but I really must add to it.

Your key "facts" are anything but that. For example, as nsxtasy said an R&P is obviously across all gears. In terms of your 1/4 mile time it is also probably more important above 60 mph than below it. Why? Because if you really are doing 0-60 in 4.0 then you are spending more than twice that much time accelerating the rest of the way down the ¼ and the lower ratio is working for you all the way. Sure, you may benefit out of the hole if your car doesn't have guts to spin the tires though 1st gear, but then it's just numbers from there on up. So if changing the R&P gains you .4 seconds 0-60 but nothing more through the 1/4, despite the same number of shifts in each range, then either you aren't driving it properly or something else is very wrong.

But the bottom line that I tried to be tactful about previously is that .4 improvement in the 1/4 from just the R&P is improbable at best, and .4 off your 0-60 from just that mod is quite simply impossible. You can scream "facts" in upper case all you want, but your credibility is dwindling rapidly.

SJS- Please...... My creditbility come on, you have got to be kidding. I am not some punk kid out there trying to build hype to get a race going. If you don't believe me bring your happy self to Nashville and I will show you. Hell, if my NSX is not doing what I say, I will pay your travel expenses. If you give me the BS excuse that you cant, how about Barnman's word. I will drag him to the track and show him in person. I guess to prove the point we will have to pull the gears out, run the car, get times, then pit the NSX for 10-12 hours, change gears and run again.

Deal with this fact, I have run the car over 30 times down the official 1/4 mile. I have done a best without 4.235 R/P 12.8 and best with the new R/P 12.4, all NA. I have 10 slips in the 11.6-11.8 range all pre 4.235 with Nitrous. So I ask what is the big deal? How are you going to argue with the time slips. I have 6 runs from one night 12.8-12.9 pre R/P and 3 runs from post R/P 12.4-12.5. It was not a fluke. They are consistent within one too two-tenths.

I did a R/P on my car, I share the info with fellow NSXers and here you are acting like a 10 year old saying "no way you did that" because you did not do it yourself.
Now you are all but calling me a liar. Real nice way to act. Are you Jealous or just a jackass? Why don't you go over to one of the kiddy boards and pull this crap!

 

[NSX/MR2]

AJKS,

I believed you! I personally have ran my NSX and found it quite satisfying with just some minor mods, so 12.9 stock for the improved NSX is definitely not out of the question one bit.

I drove all my cars pretty hard and have went through three set of clutches already in a year-and-a-half.

 

[AJKS]

Actually, changing the R&P results in an improvement in every gear, but also results in a degradation at certain speeds - namely, those where the R&P requires that you're in a higher gear. This negates some of the advantage of the R&P. In general, you can expect an overall improvement in 0-60 but an overall degradation at speeds over 60 mph.



SJS- If you are going to quote someone make sure you do it with some degree of accuracy........See the above it says "In general, you can expect an overall improvement in 0-60 but an overall degradation at speeds over 60 mph."

Look at the 0-60 and 1/4 mile # again on the post by nsxtacy.
You will see an NSX T with the 4.55 improve 0-60 by .33 and 1/4 by only .19 so what is your answer for this case? This proves what I am saying 4.235 is better gear choice in the 1/4 over stock and 4.55. You get the .4 improvement (in my case) 0-60 but keep it in the 1/4. So the 4.55 lost some of its 0-60 gain at the end of the 1/4. Why do you think the NSX R came with the 4.235???? Because they did make a large difference in the 0-60 and 1/mile.

 

[nsxtasy]

Deal with this fact, I have run the car over 30 times down the official 1/4 mile. I have done a best without 4.235 R/P 12.8 and best with the new R/P 12.4, all NA. I have 10 slips in the 11.6-11.8 range all pre 4.235 with Nitrous. So I ask what is the big deal?

The "big deal" is that the variation in your driving inputs, tire grip, and other factors from one run to another to another are the likely cause of the difference in times, not the change in R&P. The physics calculations say that you won't get a 0.4 second improvement by changing the R&P. Is your car immune to the laws of physics?

P.S. The NSX with the 4.55 R&P will accelerate faster in each gear than the 4.235 R&P. And I don't think you can say that any R&P is the best, since each has its pluses and minuses.

 

[nsx1]

Empirical data overrules hypothesis.

 

[sjs]

Once again I'll echo nsxtasy, which is really all that needs to be said. But that never stopped me before.

If you look back you will find that I'm not the one acting like a kid. I'm questioning your claims based on sound and simple physics backed up by the real-world experiences of countless NSX owners before you. In my book those combined carry much more weight in this discussion than your time slips which are subject to many[/]b variables from day to day. My comment about credibility is meant to say that if your claims, and most emphatic claims at that, don’t stand up to scrutiny for whatever reason, and you refuse to acknowledge even the possibility that you are mistaken, then it is natural to question any and all claims. That’s what credibility is, but it’s not necessarily about honesty.

I've never questioned the times you ran, just the reasons for the differences. And I certainly won't be the least jealous of anything you can do on a drag strip until you do in fact break the laws of physics, which would make you special indeed. You seem to agree with nsxtasy's numbers that show only .33 from a 4.55. How then do you gain .40 from just a 4.235? As for the apparent loss in his example from there to the 1/4, might there be an extra shift involved? If not then I question those numbers as well, but I think you’ll find that there is.

I may be dense at this late hour, but I still don't understand this:

"SJS- If you are going to quote someone make sure you do it with some degree of accuracy........See the above it says "In general, you can expect an overall improvement in 0-60 but an overall degradation at speeds over 60 mph."

So long as you don’t require an extra shift by the end of the run (which you don’t in your case) then please explain how a lower (higher numeric) R&P can degrade acceleration in higher gears? As so often discussed here, it will be slower in very narrow bands of MPH, defined by the new shift point and the old shift point where you are briefly in a higher gear than you were at the same MPH with the old R&P. But outside those small ranges it will pull harder, and if at the end of a fixed distance run you are in the same gear as with the old setup then you will see a net improvement in each gear if driven correctly.

The problem here is that not all of us are will to take time slips from different days or seat of the pants testimony over simple math and years of similar runs by people before you. I’m sorry that it got so ugly, but I’d be even more sorry if the next guy dropped $2500 bucks to get .4 seconds 0-6 and got .2 instead. That's the big deal.

 

[sjs]

Empirical data overrules hypothesis.

Only if collected scientifically and with witnesses, but we're not talking hypothesis here.

hy·poth·e·sis ( P ) Pronunciation Key (h-pth-ss)
n. pl. hy·poth·e·ses (-sz)
A tentative explanation for an observation, phenomenon, or scientific problem that can be tested by further investigation.
Something taken to be true for the purpose of argument or investigation; an assumption.
The antecedent of a conditional statement.

At least I wouldn't consider mathematical calculations or gobs of prior experience to fit that definition, but I'm no scholar. Point is, I can't leap tall buildings and no amount of saying I can will change that.

 

[1BADNSX]

Perhaps Bob can run the 4.235 through his model to calculate the figures for this R&P on a '97+ six-speed.

When I originally performed the computations, the 4.23 wasn’t an option for the 6-speed, therefore I didn’t include that permutation in the article. But now that AJKS has broken that barrier, here are the numbers compared to a stock 97+ coupe and the 4.55 R&P.

Speed Stock 4.23R&P 4.55R&P
0-30 | 2.03 | 1.94 | 1.80
0-40 | 2.67 | 2.56 | 2.38
0-50 | 3.77 | 3.68 | 3.54
0-60 | 4.79 | 4.67 | 4.47
0-70 | 5.89 | 5.76 | 5.92
0-80 | 7.61 | 7.49 | 7.28
0-90 | 9.20 | 9.05 | 9.12
0-100 | 11.04 | 11.26 | 11.06
0-110 | 13.71 | 13.55 | 13.27
0-120 | 16.44 | 16.26 | 16.41
0-130 | 20.30 | 20.22 | 19.90

1/4mile 13.24 | 13.17 | 13.06

Some general comments:

1) Computations like this are more precise at determining the difference between gear-sets because of the inevitable variations between experimental runs. They are not more accurate.

2) Other mods to any NSX would make the results different, but usually as the car gets faster, gaining .xx seconds gets harder.

3) Lowering the ring & pinion gearing and claiming continuous acceleration improvement is the biggest myth in motorsports. Yes it helps up to the first engine torque peak in first gear, but it hurts you as often as it helps after this speed.

3) It is much easier to improve zero-to-speed (0-60 mph) times than it is zero-to-distance. Let me explain by using an example. According to Road & Track numbers a 1998 NSX takes 4.9 seconds to go zero-to-sixty and 13.3 seconds to cover the quarter mile. A Ford Focus takes 9.3 seconds zero-to-sixty and 16.9 seconds for the quarter mile. As you can see, the Ford Focus takes 90% more time to reach a certain speed, but it only takes 27% more time to cover the same distance. Technically this is the case because time-to-speed is inversely proportional to acceleration, while time-to-distance is inversely proportional to the square root of acceleration. If you doubled the acceleration of a vehicle, you would decrease the zero-to-speed time by 50% (1/2), but would only reduce the zero-to-distance time by 29% (1/squareroot2).

Hope this helps,
Bob

 

[Ponyboy]

Bob, my head hurts.

Good read so far. Take out the personal attacks and it's even better.

 

[Larry Bastanza]

4.235s are u had it up to 170??? Do you have to recalibrate the speedometer gear on the 02+'s??? If you didn't and need to, then it may be an inaccurate reading.

This is only an issue if you change tire size. Gearing does not effect the speedo, since the speedo gear is part of the ring gear/diff, which is connected directly to the wheels.

HTH,
LarryB

 

[sjs]

Bob,

Thanks for chiming in!

As you say, there is a difference between “precise” and “accurate”, or stated more simply (at least as I interpret it), between relative and absolute. We are not really concerned with the absolute values here in terms of time slips, but rather the before vs after difference and the possible explanations for that difference. As your calculations clearly suggest, the stated improvements are not just slightly optimistic, but are more than triple what is expected 0-60 and even further off in the ¼ (more on that in a minute). I gather that you credit your methods with being closer than +/- 300% when comparing the difference expected from such mods, so they would seem to strongly support the notion that such gains from the R&P alone can and should be questioned. I have a pretty good simulator at home and will repeat the calculation with that and see how they compare. Something that bother me about the ¼ mile number is that it appears that may include an extra shift even for the 4.235 R&P, which doesn’t sound right but I haven’t done the math.

Your 3rd point does bother me a bit. Not because it is wrong, in fact for the most part it is consistent with what we have said here in similar debates all along. But because it does not clearly cover the specifics it can easily be misconstrued. It all revolves around keeping in mind the difference between acceleration at a given MPH vs. at a given RPM point. The nature of the “test” determines whether it helps ort hurts, where, when and how much. Obviously what works best on a road course is far more complex than the drag strip. But if you isolate a finite run like the ¼ mile, and you R&P change slightly increases the max RPM achieved in the final gear before the finish, then within that gear your acceleration should be better than before the change with the exception of the few MPH between the old shift point and the new one. During that brief time you are already in a higher gear than you were at the same speed with the original R&P and therefore at a gearing disadvantage. But narrow since the gearing change was only 4% that range is very brief and hardly constitutes as hurting as often as it helps. Of course if the shift takes place just before the end of the run then you can’t make up that lost time, but since in this case it will use nearly all of that gear, for the last half of the run you have the 4% working for you. My expectation is that it will yield a net gain for that gear. Applying the same logic (or lack of if I’m all wet) I would expect a net gain in each gear before the final one.

I am not an engineer, nor an expert on this topic, so I welcome a genuinely knowledgeable and factual rebuttal of anything I’ve said. However, the core subject here is not the fine technical details behind the numbers, but rather the voracity of the claimed end result. Specifically, can one achieve an improvement of 0.4 seconds in both 0-60 and ¼ times in a largely stock NSX merely by installing a 4.235 R&P? I have still seen absolutely nothing to suggest that my assertions on that point are incorrect, and everything to support them. If I am to be flamed for pointing out what appears to be significantly flawed claims on a subject of interest to many, then by all means flame away.

Bob, if your calculations could also yield a series of speed to distance points en route to the ¼ mile as well as shift points in MPH it would greatly aid interpretation.

 

[1BADNSX]

Something that bother me about the ¼ mile number is that it appears that may include an extra shift even for the 4.235 R&P, which doesn’t sound right but I haven’t done the math.

Your 3rd point does bother me a bit. Not because it is wrong, in fact for the most part it is consistent with what we have said here in similar debates all along. But because it does not clearly cover the specifics it can easily be misconstrued. It all revolves around keeping in mind the difference between acceleration at a given MPH vs. at a given RPM point.

Bob, if your calculations could also yield a series of speed to distance points en route to the ¼ mile as well as shift points in MPH it would greatly aid interpretation.

1) No, all three cases require a shift to 4th gear for the 1/4 mile.

2) I think you understand my comment and I agree that it can be misconstrued. When I say it will help or hurt, I mean at any fixed mph. Who cares the RPM. To do a 1/4 mile run or on a road course, you must start at one speed (mph) and accelerate as much as possible, therefore you cross through all of the speeds (mph) in question.

3) Yes, a graph would be helpful. Will post if I get around to it before heading to Atlanta for business on Sunday.

Bob

 

[nsx1]

In short, "accuracy" is how close you are to the true value. "Precision" is the resolution of the measurement. The two are not related in the sense that 1) two rulers which have tenth inch increments have the same precision... yet one of the rulers has a 10% greater error in accuracy (i.e its inch increment is 10% longer or shorter), or 2) two rulers can have the same accuracy (i.e. their inch increments are the same) but one has tenths increment (less precise) and the other has 16ths increments (more precise).

Just thought I'd throw that in.

 

[sjs]

In short, "accuracy" is how close you are to the true value. "Precision" is the resolution of the measurement...
Just thought I'd throw that in.

Yep, that works for me. Thanks!

 

[AJKS]

The "big deal" is that the variation in your driving inputs, tire grip, and other factors from one run to another to another are the likely cause of the difference in times, not the change in R&P. The physics calculations say that you won't get a 0.4 second improvement by changing the R&P. Is your car immune to the laws of physics?

P.S. The NSX with the 4.55 R&P will accelerate faster in each gear than the 4.235 R&P. And I don't think you can say that any R&P is the best, since each has its pluses and minuses.

First off, how many 1997-2002 NSX's out there have the same mods done as me, many right? How many with the gear swap one maybe two others?The only thing that is just like my NSX is an NSX R that has all but the IHE and Comptech PG II set up done and is a bit less weight. So lets see here, the NSX R is a 12.8/4.4 0-60, right? So take an NSX R and do what I have done to my NSX... Do you think it would go from a 4.4 0-60 down to a 4.07 and a 12.8 down to a 12.4 1/4 mile? I think the R would be a bit faster. So explain this to me SJS, nsxtacy, how does an NSX R have a 4.4 0-60 with only weight savings and 4.235's compared to 4.9 or 5.0 Road and track #'s 0-60 for the same year model?

 

[AJKS]

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? Because I am here to tell you my NSX was not ever going to see better than a 4.4 0-60, 12.8 1/4 without a gear swap or slick. I did the gear swap and then the 12.4 magically appeared at the track. The 60 ft by the way was almost the same as the 12.8 runs before the swap, the tires hooked the same from one night to the next. I guess because it was 60 degrees out and not 70 my NSX was .4 faster in the 0-60 and 1/4 mile.

 

[NSX/MR2]

The time sounds right given that the stock 2002/2003 are already clocking around 12.9s - 13.9s. So with the short gear, 12.4 is manageable.