Best NSX Performance Upgrades
- Thread starter melmark
- Start date
The best place to spend your money is on "the nut that holds the wheel". :wink:
I guess it would be the 6 speed swap. Maybe others can put some input on this one. Btw nice collection of cars you have there.
agree with the tranny, gears...
headers wouldn't hurt.
x
headers wouldn't hurt.
x
I agree with ChoppsJazz. But an even cheaper alternative is some Type-r stickers and glowing windshield washer nozzles. :biggrin:
On the early 3.0L cars headers create an impressive gain, from a numbers point of view.
I agree with Ken, also. Go sign up for some track events, and improve your skills. That will make a MUCH bigger difference in the performance of your car than a few aftermarket parts.
However, to answer your specific question:
Stock '91 NSX with no gearing changes: 13.67 seconds
Stock '91 NSX with 4.235 R&P: 13.57 seconds
Stock '91 NSX with 4.55 R&P: 13.43 seconds
Stock '91 NSX with short gears: 13.56 seconds
Stock '91 NSX with six-speed: 13.56 seconds
Stock '91 NSX with mods adding 15 horsepower: 13.35 seconds
Stock '91 NSX with 100 pounds weight reduction: 13.51 seconds
However, to answer your specific question:
Bob Butler has done the math. Here are his results for 1/4 mile times:melmark said:
Stock '91 NSX with no gearing changes: 13.67 seconds
Stock '91 NSX with 4.235 R&P: 13.57 seconds
Stock '91 NSX with 4.55 R&P: 13.43 seconds
Stock '91 NSX with short gears: 13.56 seconds
Stock '91 NSX with six-speed: 13.56 seconds
Stock '91 NSX with mods adding 15 horsepower: 13.35 seconds
Stock '91 NSX with 100 pounds weight reduction: 13.51 seconds
ChopsJazz said:
I would have to agree with this. The best performance any car can have is a driver that knows what he/she is doing. Same thing with motorcycles. Plus it's an upgrade that will transfer easily from vehicle to vehicle for the life of the driver!
Ok anyhow.... I'm told the short gears are AMAZING. I've overheard many experienced nsx owners who race or track their cars say that if they were to do only ONE upgrade in the car, it would be the short gears. Plus it's annoying how a redline shift from 1st, will drop the car out of the Vtec range in 2nd. Then ya gotta wait till it opens up again.......
For track use, I disagree. 1000 percent.KooLaid said:
Short gears give better acceleration than stock between 45 and 73 mph, and worse acceleration than stock above 73 mph. On most tracks, you spend all your time at speeds above 60-70 mph. Above those speeds, short gears accelerate worse, because they force you into a higher gear. With the stock five-speed, you can use second gear in the slow turns and it gives you nice acceleration up to redline (at 81 mph). With the short gears, you almost never can take advantage of second gear, and you're stuck with the slower acceleration of third gear in the slowest turns.
This is another fallacy. The NSX accelerates faster after the upshift simply because the gearing is shorter. As you can see in the torque curve in the graph below, there is no significant difference in acceleration (torque) at 4500 RPM (after upshifting to second with the stock 5-speed) than at 5100 RPM (after upshifting with the short gears). The difference due to the shorter gear ratio is 13 percent; the difference due to greater torque is about 2-3 percent.KooLaid said:
Also, FWIW, you are below the VTEC crossover point (5800 RPM) after upshifting with the short gears, too.
nsxtasy said:
Ken,
Dumb question perhaps but...
if you have added an aftermarket chip like the Dali Racing Hot Chip or the ScienceofSpeed ECU which both raise your revlimit by something like 200-300 rpm, would that solve the problem of not being able to downshift into 2nd on the track in tight curves ??
I know what after about 7800 rpm power and torque curve downwards but it might be that with the shorter gearing you still have the advantage.
nsxtasy said:For track use, I disagree. 1000 percent.
Short gears give better acceleration than stock between 45 and 73 mph, and worse acceleration than stock above 73 mph. On most tracks, you spend all your time at speeds above 60-70 mph. Above those speeds, short gears accelerate worse, because they force you into a higher gear. With the stock five-speed, you can use second gear in the slow turns and it gives you nice acceleration up to redline (at 81 mph). With the short gears, you almost never can take advantage of second gear, and you're stuck with the slower acceleration of third gear in the slowest turns.
This is another fallacy. The NSX accelerates faster after the upshift simply because the gearing is shorter. As you can see in the torque curve in the graph below, there is no significant difference in acceleration (torque) at 4500 RPM (after upshifting to second with the stock 5-speed) than at 5100 RPM (after upshifting with the short gears). The difference due to the shorter gear ratio is 13 percent; the difference due to greater torque is about 2-3 percent.
Also, FWIW, you are below the VTEC crossover point (5800 RPM) after upshifting with the short gears, too.
That is some VERY good info. Maybe it's the sound/mental aspect that makes the vtec range "feel" so much more "powerful".
I thought the reason for the 2nd gear was an emissions thing here in america? Misinformed?
Ah heck with it, I'll fix that 2nd gear thing by FI.
A play on the same theme...ChopsJazz said:
Old Timer: I figured out what's wrong with your car.
Youngster: What is it?
OT: Loose nut behind the wheel.
nsxtasy said:
Looks like you're comparing a 3.2 6speed. Would you still say the same about short gears on a 3.0 5 speed? I think the short gears on the 5 speed make sense.
ChopsJazz said:
It's interesting to see so many of you agree with me...
That being said, I, too, have the short gears and 4.23 R&P, headers and exhaust, sway bars, springs...
...and track time with instruction. :wink:
DrVolkl said:
Good point because that's what I was thinking, 5 speed since the original person who asks has got a 91.
Not really. The fact is, even if you increase the redline on the NSX, the optimal shift points (assuming a stock car) are still in the 7800-8100 RPM area. So even if you increase the rev limit, you are still going to accelerate slower with the short gears if you keep it in the lower gear up to a point where you would be better off upshifting.MvM said:
That wasn't the reason. Perhaps it was done for fuel economy; perhaps it was done to make a car that's faster at faster speeds (for our wide-open roads as well as those in Europe, although it's nice that it benefits those of us who drive on racetracks). No one (outside of Honda) really knows.KooLaid said:
Perhaps you are thinking of the Corvette, and its feature that forces a shift from first gear to fourth when driven gently, for better EPA fuel economy figures?
nsxtasy said:
No, not at all. I'm comparing a five-speed with stock gears against a five-speed with short gears. The stock gears are quicker between 73 and 81, where they are in second gear, than the short gears, which are in third gear at those speeds. Similarly, the stock gears are quicker between 101 and 114 mph, and between 139 and 144 mph. And the difference in acceleration is much greater than at the speeds where the short gears have the advantage.DrVolkl said:
This is reflected in the overall acceleration numbers for the five-speed:
0-40 mph:
2.84 seconds (both setups)
40-70 mph:
3.75 seconds (stock gears)
3.43 seconds (short gears)
70-150 mph:
31.19 seconds (stock gears)
34.79 seconds (short gears)
You're welcome to your opinion. And they may make sense for the person looking for a bit of extra speed "off the line", at stoplights and highway entrance ramps, as well as someone who likes the feel of a shorter second gear. But the numbers are what they are; the primary advantage is below 73 mph, and overall they are a detriment above that speed, which is pretty much where almost all racetrack driving occurs.DrVolkl said:
nsxtasy said:
As far as the reason for the Japanse short gears, I think that actually it is the other way around. Since in Japan all cars are limited to 180 kph (112 mph) the shorter gears are much more usefull since that where most of the fun will (have to) happen. Long gearing makes no sense in a car that is limited anyway.
As for as the numbers, where did you get those numbers from ??
The table in the faq only goes to 140mph and if I look there the numbers are:
40-70 mph:
4.07 seconds (stock gears)
3.68 seconds (short gears)
70-140 mph:
31.94 seconds (stock gears)
31.31 seconds (short gears)
These numbers differ noticably from the numbers that you have, especially since the FAQ lists 31.94 secons for 70-140mph where you give an even faster time of 31.19 seconds (stock gears) for 70-150mph.
nsxtasy said:
I should have prefaced this post with the fact that I'm rarely going to go over 100mph anyway. I'm looking for 0-60 acceleration, better stop light performance. My 91 is a daily driver, will never see the track.
looks like a few HP is the way to go. Beats gear changes easily.
Osiris_x11
Gold Member, Moderator: Marketplace
power-train to drive-train, in terms of mod's...
('91-'94, '95-96, '97-'00, '01-'05 all had some variation in the exhaust-manifold -> cat -> exhaust/muffler)
I/H/E (20-25rwhp) is a good start while fine-tuning your skills w/ the MR-layout of the NSX at HPDE's and other track events.
In addition, throw in an ECU-chip, wider-bore throttle-body, ~100lbs. weight reduction, and grippy-tires... should be able to break into 12's in the 1/4 (I *assume*).
Less than half the cost, more than twice the headache w/ most of the gain.melmark said:
('91-'94, '95-96, '97-'00, '01-'05 all had some variation in the exhaust-manifold -> cat -> exhaust/muffler)
I/H/E (20-25rwhp) is a good start while fine-tuning your skills w/ the MR-layout of the NSX at HPDE's and other track events.
In addition, throw in an ECU-chip, wider-bore throttle-body, ~100lbs. weight reduction, and grippy-tires... should be able to break into 12's in the 1/4 (I *assume*).
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Have a look here too: http://www.nsxprime.com/forums/showthread.php?t=44961
Due to your needs "I should have prefaced this post with the fact that I'm rarely going to go over 100mph anyway. I'm looking for 0-60 acceleration, better stop light performance. My 91 is a daily driver, will never see the track." the shorties AND the 4.23 should be perfect for you. 6-speed has it's advantages only above 100 mph and is much too expensive IMO.
Instead of a OEM 4.23 you could have a look into this one: http://www.nsxprime.com/forums/showthread.php?t=74761.
I'm still very happy with it, best most ever on my car.
Due to your needs "I should have prefaced this post with the fact that I'm rarely going to go over 100mph anyway. I'm looking for 0-60 acceleration, better stop light performance. My 91 is a daily driver, will never see the track." the shorties AND the 4.23 should be perfect for you. 6-speed has it's advantages only above 100 mph and is much too expensive IMO.
Instead of a OEM 4.23 you could have a look into this one: http://www.nsxprime.com/forums/showthread.php?t=74761.
I'm still very happy with it, best most ever on my car.
I have short gears + 4.55 R&P (and supercharger). I'm quite happy with the gearbox but I see a lot of value in the 6-speed conversion as well...especially for increased-horsepower cars (if I could go back in time might opt for 6-speed conversion instead...not sure). The cost of 6-speed conversion (assuming used 6-speed) doesn't seem like it would be significantly higher than having short gears & new synchro/sleeve sets put in a 5-speed.
The FAQ entry for Gears has a lot of the information you'd want. The "what are the numbers" will run down the 0-to-XXX times for various setups. If you want to compare acceleration times other than from zero (i.e. 50-70) you can take the difference between the two 0-XXX times (i.e. 0-50 and 0-70) for both setups. It won't make the decision obvious because it highlights the trade-offs (all setups will be slow in some ranges and fast in others depending on shift points). Sicne you don't think you'll see or don't care about getting to 100, 120, 140, 160, etc - the decision might be quite a bit easier for you.
That section and it's table of numbers does make a pretty good case for horsepower increases (and to a lesser extent, weight reduction/avoidance) because of the across-the-board effect (which gear changes don't do, since they only change how power is used...not the amount of power).
The FAQ entry for Gears has a lot of the information you'd want. The "what are the numbers" will run down the 0-to-XXX times for various setups. If you want to compare acceleration times other than from zero (i.e. 50-70) you can take the difference between the two 0-XXX times (i.e. 0-50 and 0-70) for both setups. It won't make the decision obvious because it highlights the trade-offs (all setups will be slow in some ranges and fast in others depending on shift points). Sicne you don't think you'll see or don't care about getting to 100, 120, 140, 160, etc - the decision might be quite a bit easier for you.
That section and it's table of numbers does make a pretty good case for horsepower increases (and to a lesser extent, weight reduction/avoidance) because of the across-the-board effect (which gear changes don't do, since they only change how power is used...not the amount of power).
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