Ilya, 4.55
- Thread starter JChoice
- Start date
I think as a general rule that it's best to finish near the top of fourth for the best 1/4 mile times.
The following is based on estimates.
The scenario I'm using (6 speed trapping at 7600 rpms in fourth gear) looks like:
124mph - 4.026 (stock) -> estimated 490HP
118mph - 4.235 -> estimated 420HP
110mph - 4.55 -> estimated 325HP
The above means that as one neared 420HP, they would be quicker with a 4.235 ring and pinion than with a 4.55.
There can also be an issue with too much torque and too little traction in first gear.
W
Very informative, thank you.
What about a 5 speed and does that mean that the 4.55 will work better for a lower HP car in quarter mile acceleration?
Is finishing at the top of 4th the best because you save the additional time it takes to shift to fifth?
What about a 5 speed and does that mean that the 4.55 will work better for a lower HP car in quarter mile acceleration?
Is finishing at the top of 4th the best because you save the additional time it takes to shift to fifth?
Here (courtesy of Bob Butler) are the 1/4 mile times for various configurations, holding horsepower constant, assuming a '91 with stock engine and exhaust, and a total weight including the driver of 3200 pounds:
stock 5-speed and stock R&P: 13.67 seconds
stock 5-speed and 4.235 R&P: 13.57 seconds
stock 5-speed and 4.550 R&P: 13.43 seconds
short 5-speed and stock R&P: 13.56 seconds
short 5-speed and 4.235 R&P: 13.48 seconds
short 5-speed and 4.550 R&P: 13.38 seconds
stock 6-speed and stock R&P: 13.56 seconds
stock 6-speed and 4.550 R&P: 13.36 seconds
As you can see, changes in gearing don't make a whole lot of difference in overall acceleration.
[This message has been edited by nsxtasy (edited 03 January 2002).]
stock 5-speed and stock R&P: 13.67 seconds
stock 5-speed and 4.235 R&P: 13.57 seconds
stock 5-speed and 4.550 R&P: 13.43 seconds
short 5-speed and stock R&P: 13.56 seconds
short 5-speed and 4.235 R&P: 13.48 seconds
short 5-speed and 4.550 R&P: 13.38 seconds
stock 6-speed and stock R&P: 13.56 seconds
stock 6-speed and 4.550 R&P: 13.36 seconds
As you can see, changes in gearing don't make a whole lot of difference in overall acceleration.
[This message has been edited by nsxtasy (edited 03 January 2002).]
It seems that the 4.55 should really help quarter mile times - anyone know why it might hurt quarter mile times?
It could hurt quarter mile times if it causes an additional upshift that wouldn't be needed with a lower numerical value R&P. This was not true for the 270 hp car used in the example above, but it could be true for a car with more horsepower than that.
It could hurt quarter mile times if it causes an additional upshift that wouldn't be needed with a lower numerical value R&P. This was not true for the 270 hp car used in the example above, but it could be true for a car with more horsepower than that.
With a 5-speed on a mostly stock engine, 3rd gear, which tops at 114, should get you through the quarter. However, if you got the 4.55, 3rd gear would run out at 101mph, and you'd probably have to hit 4th to finish the quarter, and that extra shift might offset the extra accelleration gains.
-Mike
Ken,
I believe those figures and I suspect that with 0-100 MPH times the differences would be even less.
But I think that for "most" people the appeal of lower gears is for faster acceleration in any single gear, like 1st or 2nd, on the street.
It may be that the true measurement of lower gears like the 4.55s isn't a 0-60 time (which might involve a shift) or a 1/4 mile time (which will involve several shifts) but perhaps the time it takes to reach redline after a standing start or from a roll.
In this test I think you would see a more significant difference and also an explanation why "the 4.55 gears feel faster" on the street.
-Jim
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1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords
I believe those figures and I suspect that with 0-100 MPH times the differences would be even less.
But I think that for "most" people the appeal of lower gears is for faster acceleration in any single gear, like 1st or 2nd, on the street.
It may be that the true measurement of lower gears like the 4.55s isn't a 0-60 time (which might involve a shift) or a 1/4 mile time (which will involve several shifts) but perhaps the time it takes to reach redline after a standing start or from a roll.
In this test I think you would see a more significant difference and also an explanation why "the 4.55 gears feel faster" on the street.
-Jim
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1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords
I think that for "most" people the appeal of lower gears is for faster acceleration in any single gear, like 1st or 2nd, on the street.
But they don't get any significantly faster acceleration - and I thought that's what the question here was about, real acceleration, not perceived acceleration.
In this test I think you would see a more significant difference and also an explanation why "the 4.55 gears feel faster" on the street.
Of course. Let's say that the 4.55 R&P accelerates exactly as fast as the stock R&P. So the stock R&P takes x seconds to get from 0 to 30 mph, where it's at 6000 rpm. But it still takes more time to get to redline. The 4.55 R&P also takes x seconds to get from 0 to 30 mph, where it hits redline. So someone might imagine that they're going faster because they hit redline faster - even though the actual rate of acceleration is exactly the same. This can create the perception of faster acceleration, even though the acceleration is exactly the same.
This is a slight oversimplification; in fact, the 4.55 R&P will accelerate faster in first up to redline, but above that speed, the stock R&P accelerates faster, since it's still in first gear. Since the overall differences are minor, it illustrates the point.
This is like different aftermarket exhausts, where people will swear that the loudest exhaust is the fastest. (I'm not saying that the acceleration with different exhausts is equal - it's not - but only pointing out that sometimes perceived acceleration doesn't correlate with real acceleration.)
However, I think most people are looking for real gains in acceleration, not perceived gains - as is reflected in the original question here, about 1/4 mile times.
But they don't get any significantly faster acceleration - and I thought that's what the question here was about, real acceleration, not perceived acceleration.
In this test I think you would see a more significant difference and also an explanation why "the 4.55 gears feel faster" on the street.
Of course. Let's say that the 4.55 R&P accelerates exactly as fast as the stock R&P. So the stock R&P takes x seconds to get from 0 to 30 mph, where it's at 6000 rpm. But it still takes more time to get to redline. The 4.55 R&P also takes x seconds to get from 0 to 30 mph, where it hits redline. So someone might imagine that they're going faster because they hit redline faster - even though the actual rate of acceleration is exactly the same. This can create the perception of faster acceleration, even though the acceleration is exactly the same.
This is a slight oversimplification; in fact, the 4.55 R&P will accelerate faster in first up to redline, but above that speed, the stock R&P accelerates faster, since it's still in first gear. Since the overall differences are minor, it illustrates the point.
This is like different aftermarket exhausts, where people will swear that the loudest exhaust is the fastest. (I'm not saying that the acceleration with different exhausts is equal - it's not - but only pointing out that sometimes perceived acceleration doesn't correlate with real acceleration.)
However, I think most people are looking for real gains in acceleration, not perceived gains - as is reflected in the original question here, about 1/4 mile times.
With a 5-speed on a mostly stock engine, 3rd gear, which tops at 114, should get you through the quarter. However, if you got the 4.55, 3rd gear would run out at 101mph, and you'd probably have to hit 4th to finish the quarter, and that extra shift might offset the extra accelleration gains.
The extra shift is partly responsible for offsetting acceleration gains. The other part is that acceleration is lower if the overall gearing is higher. There are speeds (e.g. 101-115 mph) where the overall gearing with the 4.55 R&P is higher (and acceleration slower) because you have to be in fourth gear, whereas with the stock R&P the gearing is lower and the acceleration faster because you can stay in third gear.
The extra shift is partly responsible for offsetting acceleration gains. The other part is that acceleration is lower if the overall gearing is higher. There are speeds (e.g. 101-115 mph) where the overall gearing with the 4.55 R&P is higher (and acceleration slower) because you have to be in fourth gear, whereas with the stock R&P the gearing is lower and the acceleration faster because you can stay in third gear.
Ken,
I think you misunderstood me. I understand the issue of "perception" of speed. That's not what I was discussing. I was talking about actual and real gains in acceleration.
Let me try it again...
My point was that the longer the run (i.e. 1/4 mile) the less the actual difference in acceleration from the 4.55 gears will matter. The extra shifts and the hitting the redline sooner take their toll.
I don't believe it's true when you say that the 4.55 R&P takes the same amount of time to get from 0-30 as does the stock R&P. In fact, I think that's where you're going to see the most improvement on a percentage basis.
Since you're starting off from a dead stop, the added mechanical advantage of the 4.55 will make more of a percentage difference in the early goings than in the 1/4 mile and certainly on the race course where you never really start from a dead stop.
I believe it's the stop-and-go nature of street driving and the acceleration from a dead stop or a roll that makes the 4.55 gears faster. It all depends on the interval that you're examining.
I also think this explains the "perception" issue. What they're perceiving is the actual faster acceleration on that initial start-up and that feels good.
-Jim
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1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords
I think you misunderstood me. I understand the issue of "perception" of speed. That's not what I was discussing. I was talking about actual and real gains in acceleration.
Let me try it again...
My point was that the longer the run (i.e. 1/4 mile) the less the actual difference in acceleration from the 4.55 gears will matter. The extra shifts and the hitting the redline sooner take their toll.
I don't believe it's true when you say that the 4.55 R&P takes the same amount of time to get from 0-30 as does the stock R&P. In fact, I think that's where you're going to see the most improvement on a percentage basis.
Since you're starting off from a dead stop, the added mechanical advantage of the 4.55 will make more of a percentage difference in the early goings than in the 1/4 mile and certainly on the race course where you never really start from a dead stop.
I believe it's the stop-and-go nature of street driving and the acceleration from a dead stop or a roll that makes the 4.55 gears faster. It all depends on the interval that you're examining.
I also think this explains the "perception" issue. What they're perceiving is the actual faster acceleration on that initial start-up and that feels good.
-Jim
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1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords
My point was that the longer the run (i.e. 1/4 mile) the less the actual difference in acceleration from the 4.55 gears will matter. The extra shifts and the hitting the redline sooner take their toll.
That's true. You also have the alternating "speed bands" in which the 4.55 R&P accelerates slower. The 4.55 accelerates faster while both gearing setups are in first gear. But when you upshift to second with the 4.55 R&P, it accelerates WORSE than with the stock R&P, which is still in first gear. See my note above in response to Mike's note.
I don't believe it's true when you say that the 4.55 R&P takes the same amount of time to get from 0-30 as does the stock R&P.
I was using that as a hypothetical example; the words "Let's say" were the tip-off. I then followed it in the next paragraph with the statement, "This is a slight oversimplification; in fact, the 4.55 R&P will accelerate faster in first up to redline". Perhaps you missed that part?
I believe it's the stop-and-go nature of street driving and the acceleration from a dead stop or a roll that makes the 4.55 gears faster. It all depends on the interval that you're examining.
That's true. However, it still doesn't make all that much of a difference. For example, with the stock gears using Bob's example, 0-30 takes 2.16 seconds. The 4.55 R&P brings that down to 1.91 seconds. Faster? Yes. But the difference is only a quarter of a second - and overall, there is basically no additional advantage in acceleration at speeds over 30 mph, since that quarter second is the same as the difference in the entire quarter mile.
If your point is that there is a bigger difference below 30 mph than above, you are correct; one quarter second is bigger than zero. But it's still only one quarter of a second. Since it occurs at less than 30 mph, that's a difference of less than one car length in the 1/4 mile.
That's true. You also have the alternating "speed bands" in which the 4.55 R&P accelerates slower. The 4.55 accelerates faster while both gearing setups are in first gear. But when you upshift to second with the 4.55 R&P, it accelerates WORSE than with the stock R&P, which is still in first gear. See my note above in response to Mike's note.
I don't believe it's true when you say that the 4.55 R&P takes the same amount of time to get from 0-30 as does the stock R&P.
I was using that as a hypothetical example; the words "Let's say" were the tip-off. I then followed it in the next paragraph with the statement, "This is a slight oversimplification; in fact, the 4.55 R&P will accelerate faster in first up to redline". Perhaps you missed that part?
I believe it's the stop-and-go nature of street driving and the acceleration from a dead stop or a roll that makes the 4.55 gears faster. It all depends on the interval that you're examining.
That's true. However, it still doesn't make all that much of a difference. For example, with the stock gears using Bob's example, 0-30 takes 2.16 seconds. The 4.55 R&P brings that down to 1.91 seconds. Faster? Yes. But the difference is only a quarter of a second - and overall, there is basically no additional advantage in acceleration at speeds over 30 mph, since that quarter second is the same as the difference in the entire quarter mile.
If your point is that there is a bigger difference below 30 mph than above, you are correct; one quarter second is bigger than zero. But it's still only one quarter of a second. Since it occurs at less than 30 mph, that's a difference of less than one car length in the 1/4 mile.
Ken,
I think we're on the same page. And let me say I agree that 4.55 gears don't make a whole of difference on the 1/4 mile and may even be net loss on a road course. But...
Higher numerical gears will always accelerate quicker. It's a law of physics. If you double the gear ratio, you doubled the acceleration, but of course, you also halved the maximum speed.
The disruption caused by shifting is an issue when you're timing an event (like a 0-60 run, or a 1/4 mile drag run) and you need to shift because of the redline. I think we agree that acceleration gains can be negated if you have to shift twice as opposed to only shifting once.
But it's true that when it comes to acceleration higher numerical ratios will always benefit acceleration.
In Bob's example, the difference between 2.16 and 1.91 is a significant percentage and it's probably close to the actual numerical difference in the ratios.
Let's use an absurd example. Let's say someone installed a 9.10 R&P in their NSX. It would accelerate twice as fast as the 4.55. So in Bob's example with a 9.10 R&P the 0-30 time should be close to 0.9 seconds.
Therefore, from a standing start the car would feel ungodly quick (assuming you had the traction to take advantage of). Of course you would have to shift before you knew it, the top speed would be drastically reduced, and it would be silly, but it would accelerate very quickly. And it's acceleration that you "feel" in the seat of the pants (F=MA). And that wouldn't be a perceived acceleration, it would be real.
We know that many people claim that their car is "faster" when they install the higher numerical gearsets. I guess I'm saying that this is not a mere perception, but the reality of faster acceleration upon startup which is real and measurable. And that, in particular when it's street driving, which involves a lot of start and stop driving it makes a bigger difference to the driver than it would to the drag racer.
-Jim
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1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords
[This message has been edited by Jimbo (edited 04 January 2002).]
I think we're on the same page. And let me say I agree that 4.55 gears don't make a whole of difference on the 1/4 mile and may even be net loss on a road course. But...
Higher numerical gears will always accelerate quicker. It's a law of physics. If you double the gear ratio, you doubled the acceleration, but of course, you also halved the maximum speed.
The disruption caused by shifting is an issue when you're timing an event (like a 0-60 run, or a 1/4 mile drag run) and you need to shift because of the redline. I think we agree that acceleration gains can be negated if you have to shift twice as opposed to only shifting once.
But it's true that when it comes to acceleration higher numerical ratios will always benefit acceleration.
In Bob's example, the difference between 2.16 and 1.91 is a significant percentage and it's probably close to the actual numerical difference in the ratios.
Let's use an absurd example. Let's say someone installed a 9.10 R&P in their NSX. It would accelerate twice as fast as the 4.55. So in Bob's example with a 9.10 R&P the 0-30 time should be close to 0.9 seconds.
Therefore, from a standing start the car would feel ungodly quick (assuming you had the traction to take advantage of). Of course you would have to shift before you knew it, the top speed would be drastically reduced, and it would be silly, but it would accelerate very quickly. And it's acceleration that you "feel" in the seat of the pants (F=MA). And that wouldn't be a perceived acceleration, it would be real.
We know that many people claim that their car is "faster" when they install the higher numerical gearsets. I guess I'm saying that this is not a mere perception, but the reality of faster acceleration upon startup which is real and measurable. And that, in particular when it's street driving, which involves a lot of start and stop driving it makes a bigger difference to the driver than it would to the drag racer.
-Jim
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1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords
[This message has been edited by Jimbo (edited 04 January 2002).]
I have to disagree if you are saying that a .25 second difference in 1/4 mile ET equates to less than one car length for the examples that have been discussed. I thought that, as a general rule, each tenth of a second equated to a car length difference.
Also, '0-some speed' differences do not directly translate to '0-some distance' differences. So if car A reaches 60 in 5 seconds and car B reaches it in 4 seconds, it is not necessarily a good approximation to say that car B is 1 second faster than car A in the 1/4 mile.
Drag racing is so much about the hole shot. If you have the traction, a 4.55 ring and pinion gets you the hole shot. After that, it's catch up time for the other guy and you are already going faster to start the race.
JChoice, about a stock 5 speed, it looks like a 4.55 ring and pinion will produce faster 1/4 mile times than stock (4.026). I think a 4.55 is faster than a 4.235 even though there is an additional shift at the end because it's not like your car stops moving when you shift. It actually looks like something close to a 5.5 ring and pinion would work out best since you finish at the top of fourth if you're trapping at just under 105. For regular supercharged applications, it looks like the 4.235 is best, and the stock ring and pinion is best for high horsepower applications.
I think you want to finish at the top of fourth because of the trade-off between maximizing the area under the torque curve while sacrificing time to shift and I guess three shifts is optimal.
Well if for high horsepower, the stock configuration is better..... what about keeping the stock R&P and get the short gears?
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Kenji Ligon
91 Red CTSC NSX
[This message has been edited by Attitude Adjuster (edited 05 January 2002).]
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Kenji Ligon
91 Red CTSC NSX
[This message has been edited by Attitude Adjuster (edited 05 January 2002).]
Jimbo and Ken,
You both are on the same wavelength and understand this very well, but don't forget that you do have to shift and this prevents higher numerical gearing from always helping.
Just for grins I calculated the case Jimbo mentioned of a 9.10 R&P. Here are the results:
9.10 R&P Stock R&P
0-30 mph 1.43 seconds 2.16 seconds
0-60 mph 4.38 seconds 5.31 seconds
1/4 mile 13.71@83mph 13.67@105mph
Yes, the 9.10 R&P helps the 0-30 mph acceleration, but not as much as Jimbo guessed due to shifting from 1st to 2nd gear at 21 mph. The quarter mile time of the 9.10 R&P really suffers due to shifting into 5th gear at 66 mph and hitting redline in 5th at 83 mph and having to hold it there for the rest of the 1/4 mile run!
Bob
- Joined
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You are confusing time and distance here. If they keep the .25 second gap all the way to 100 MPH (a conservative number for an NSX at the end of the 1/4 mile) the difference is about 2.5 NSX lengths because as the speed increases the distance must also increase if the time interval stays the same.
My bad.
Bob,
Agreed. I didn't calculate where the shift point would be. If only the redline was 12K, huh?
There's been so many discussions on this topic where people install the 4.55s and swear that their car is "faster."
If you measure the 4.55s on the basis of actual 0-60 times or the 1/4 mile of course, as we've seen the difference is nil.
I was trying to offer an actual definitive reason why these people feel that their cars are faster. It's not a perception or an illusion. It's because the cars accelerate faster in direct proportion to the gear ratio change. And with normal street driving this actual difference is really felt in the seat of the pants.
As we've pointed out they might have to shift more frequently but the push back into their seats due to acceleration is real.
-Jim
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1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords
Agreed. I didn't calculate where the shift point would be. If only the redline was 12K, huh?
There's been so many discussions on this topic where people install the 4.55s and swear that their car is "faster."
If you measure the 4.55s on the basis of actual 0-60 times or the 1/4 mile of course, as we've seen the difference is nil.
I was trying to offer an actual definitive reason why these people feel that their cars are faster. It's not a perception or an illusion. It's because the cars accelerate faster in direct proportion to the gear ratio change. And with normal street driving this actual difference is really felt in the seat of the pants.
As we've pointed out they might have to shift more frequently but the push back into their seats due to acceleration is real.
-Jim
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1992 NSX Red/Blk 5 spd #0330
1991 NSX Blk/Blk Auto #3070 (Sold)
1974 Vette 454 4 spd Wht/Blk
Looking for 76-79 Honda Accords
As we've pointed out they might have to shift more frequently but the push back into their seats due to acceleration is real.
It's real if you're comparing gear setups within the same gear (without regard to road speed). It's not always real if you're comparing gear setups at the same road speed, except when they're both in first gear.
For example - the 4.55 R&P in third gear ALWAYS accelerates faster than the stock R&P in third gear. However, the stock R&P at 110 mph accelerates faster than the 4.55 R&P at 110 mph (because the stock R&P can be in third gear whereas the 4.55 R&P is in fourth gear).
I think this is another way of saying the same thing as you are, jimbo - that the 4.55 R&P feels faster because IS faster within a given gear, but is not necessarily faster at a given road speed or over a given distance.
I like the 9.1 R&P example. You'll accelerate REALLY fast up to 83 mph, but that will be your top speed. Heck, if someone brought that to market, I bet there would be people out there who would love one!
It's real if you're comparing gear setups within the same gear (without regard to road speed). It's not always real if you're comparing gear setups at the same road speed, except when they're both in first gear.
For example - the 4.55 R&P in third gear ALWAYS accelerates faster than the stock R&P in third gear. However, the stock R&P at 110 mph accelerates faster than the 4.55 R&P at 110 mph (because the stock R&P can be in third gear whereas the 4.55 R&P is in fourth gear).
I think this is another way of saying the same thing as you are, jimbo - that the 4.55 R&P feels faster because IS faster within a given gear, but is not necessarily faster at a given road speed or over a given distance.
I like the 9.1 R&P example. You'll accelerate REALLY fast up to 83 mph, but that will be your top speed. Heck, if someone brought that to market, I bet there would be people out there who would love one!
For 1/4 mile racing, the short gears are a better choice regardless of which of the three ring and pinions you choose. This is due to the stock second gear being too tall.
Yes, as you can see from the numbers, the short gears will reduce 1/4 mile times anywhere from .05 second to .11 second. Whether that small difference is worth the money, well...
Actually, that's the whole key to the issue, as I see it. If I were to choose which setup is best, the six-speed with the 4.55 R&P seems to be in many respects to be the best gearing setup, and what I would prefer in my own car. However, the differences in performance are so small that the question becomes whether any of them are worth the cost needed to swap them in. In other words - one setup may be better than another, but it's possible that no setup is worth the cost of swapping gears - especially compared with the cost and benefit of other mods that are available.
Actually, that's the whole key to the issue, as I see it. If I were to choose which setup is best, the six-speed with the 4.55 R&P seems to be in many respects to be the best gearing setup, and what I would prefer in my own car. However, the differences in performance are so small that the question becomes whether any of them are worth the cost needed to swap them in. In other words - one setup may be better than another, but it's possible that no setup is worth the cost of swapping gears - especially compared with the cost and benefit of other mods that are available.
I know what they feel because when I drive my M3, it feels faster than the NSX in a straight line due to the gearing (redline in 2nd at 63 mph), but it really isn't.
The 4.55 R&P provides REAL acceleration benefits in 1st gear (up to 41 mph), but after that the stock gearing more often (greater than 50%) is better.
But the acceleration is real. The short gears and 4.55 R&P decrease the 0-60 mph time from 5.31 to 4.74 seconds (11%), not bad, but expensive.
The improvements at the 1/4 mile drag strip are not as good (13.67 vs 13.38 seconds) because it is much more difficult to reduce time-to-distance than it is for time-to-speed. Time-to-speed is inversely proportional to acceleration, while time-to-distance is inversely propotional to the square-root of acceleration.
For instance when you takeoff in an F-16, the acceleration is roughly 1g (about twice that of an NSX) and time-to-speed is cut in half (50%), but the 1/4 mile time is still greater than 9 seconds [about 1/square-root(2), or only 29% better].
This tells you that you need to pull out all the stops to improve your 1/4 mile time and drag racers certainly need to change the NSX gearing. But on a road course, some gearing combinations work best at one track, and some better at others.
Bob
91 NSX (stock gearing)
97 M3 Club Racer
97 3.0 CL
[This message has been edited by 1BADNSX (edited 05 January 2002).]
The 4.55 R&P provides REAL acceleration benefits in 1st gear (up to 41 mph)
Hey! You can't get to 41 mph with the 4.55 R&P in first gear unless you overrev your engine!
For instance when you takeoff in an F-16, the acceleration is roughly 1g (about twice that of an NSX) and time-to-speed is cut in half (50%), but the 1/4 mile time is still greater than 9 seconds [about 1/square-root(2), or only 29% better].
This tells you that you need to
...get an F-16.
on a road course, some gearing combinations work best at one track, and some better at others.
I'll say! We have a road course near here called GingerMan Raceway. When I drive that track in my Integra Type R, I drive the entire track in third gear. Second gear in that car tops out at 66 mph, and if I downshift to second for the slow turns, I run out of revs by the time I reach the track-out point, so it just isn't worth it. And the straights aren't long enough to need fourth. With my NSX with stock '91 gearing, I'm upshifting and downshifting between second and third gears 3-5 times per lap, because second gear IS worth using (since it's good up to 81 mph). Which is better? I don't know. I suspect the NSX gearing is better because it takes advantage of the ability to use two different gears, but it sure does make you busier shifting as you go around the track. The ITR doesn't use the gears as efficiently, but it's a lot easier to drive without worrying about shifting constantly.
I would imagine that driving an NSX with short gears (and especially with a higher-numerical-ratio) around GingerMan would be more like driving the ITR, with less use of second gear than the stock NSX.
Hey! You can't get to 41 mph with the 4.55 R&P in first gear unless you overrev your engine!
For instance when you takeoff in an F-16, the acceleration is roughly 1g (about twice that of an NSX) and time-to-speed is cut in half (50%), but the 1/4 mile time is still greater than 9 seconds [about 1/square-root(2), or only 29% better].
This tells you that you need to
...get an F-16.
on a road course, some gearing combinations work best at one track, and some better at others.
I'll say! We have a road course near here called GingerMan Raceway. When I drive that track in my Integra Type R, I drive the entire track in third gear. Second gear in that car tops out at 66 mph, and if I downshift to second for the slow turns, I run out of revs by the time I reach the track-out point, so it just isn't worth it. And the straights aren't long enough to need fourth. With my NSX with stock '91 gearing, I'm upshifting and downshifting between second and third gears 3-5 times per lap, because second gear IS worth using (since it's good up to 81 mph). Which is better? I don't know. I suspect the NSX gearing is better because it takes advantage of the ability to use two different gears, but it sure does make you busier shifting as you go around the track. The ITR doesn't use the gears as efficiently, but it's a lot easier to drive without worrying about shifting constantly.
I would imagine that driving an NSX with short gears (and especially with a higher-numerical-ratio) around GingerMan would be more like driving the ITR, with less use of second gear than the stock NSX.
Originally posted by nsxtasy:
...get an F-16.
For some reason the image won't post. Checkout this shot I took holding the camera infront of me. http://www.netcolony.com/members/nsx/fly/f16max.jpg
[This message has been edited by 1BADNSX (edited 06 January 2002).]
[This message has been edited by 1BADNSX (edited 06 January 2002).]
Right. You can use 2nd gear, but it doesn't change lap times. It's mostly a 3rd gear track with short gears and 4.23 R&P. From my experience, the stock gears with the 4.55 is the best gearing for that track.
DanO
