Short Gears or Ring & Pinion?

NSXnBRLA

NSXnBRLA

Experienced Member
Joined
5 August 2001
Messages
861
Location
Baton Rouge LA
I have finally gotten tired of the OEM 2nd gear in my 92. I just feel like the car loses something when shifting to 2nd, after coming out of 1st gear at the redline. Everyone that has upgraded to the Type R gear set, says that solves this problem. I do not currently have the budget to get both the Ring/Pinion AND the short gears. Would it be wise to go with one and not the other? If so, which one would you recommend and why. Or, should I wait til my budget will allow the purchase of both? Thanks in advance for your help.

------------------
1992 NSX
 
If you're only going to do one change, and you are primarily concerned with the lack of acceleration when upshifting from first to second, get the short gears.

The reason that the car loses something when upshifting to second is that there is a big gap (difference in gear ratios) between first and second gear. What you are feeling is the loss of acceleration due to the difference in gearing.

The short gears change the ratio so that the difference between first and second is smaller (while the differences between second and third*, third and fourth, and fourth and fifth are slightly wider).

The R&P doesn't change the ratios of the individual gears, so the gap between first and second would remain if you only changed the R&P.

* (EDIT) - See correction below. The difference between second and third is ever so slightly narrower also.

[This message has been edited by nsxtasy (edited 20 November 2002).]
 
P.S. A couple more comments...

Originally posted by NSXnBRLA:
Everyone that has upgraded to the Type R gear set, says that solves this problem. I do not currently have the budget to get both the Ring/Pinion AND the short gears.
Click to expand...

There is a difference between the "Type R gear set" and the "short gears". All '91-94 NSXs sold in Japan contained the "short gears". The NSX Type R, which was sold in the Japanese market during that period, had a gear set that included the "short gears" and a 4.235 R&P. So the term "Type R gear set" refers to this particular combination of R&P and short gears.

Originally posted by NSXnBRLA:
I do not currently have the budget to get both the Ring/Pinion AND the short gears. Would it be wise to go with one and not the other? If so, which one would you recommend and why. Or, should I wait til my budget will allow the purchase of both?
Click to expand...

If you plan on getting both, you are better off doing both at the same time. The labor involved in opening up the transmission is substantial, and doing both at the same time will enable you to pay for it once, not twice.
 
Thank you sir. That helps alot. The 1st-2nd gear lag is definitely what i'm trying to correct. I've raced several EXTREMELY fast cars (vettes, camaro SS, TT supra) and every time I shift to 2nd, its bye bye for the NSX, no matter how good i'm doing through 1st. Usually, if I launch at the right RPM, none of the above mentioned cars can get out ahead of me, until I shift into 2nd. Regarding the labor costs, I own a honda/acura repair shop, and my head tech thrives on getting his hands into my car as often as possible, so if he'd have to tear it down twice, it would be no problem at all. Whats the best place to buy the short gear set? i know of at least 3 places that offer them, but I haven't looked at pricing since I made this decision to buy. Thanks again.

------------------
1992 NSX
 
What is the third place? SoS.. Dali.. and?

I still havent heard back from the dearlship in BR about my turn signals.. i will let you know what happens.
 
Originally posted by nsxtasy:
I believe you can get the short gears from any Acura dealer. The part numbers are in the FAQ.
Click to expand...

Hmm.. I did not know this.. I get 30% off at my local dealer too.. i'll be looking into this tomorrow
smile.gif



------------------
1992 NSX
 
If you drive a lot on the street and shift between 1 & 2 a lot, the short gears probably would be easier to appreciate.

However, given the choice, I would save up to do both. As Ken mentioned, the cost is largely a labor issue. Keep in mind that this is one job I would trust to very few techs. The FAQs are very informative on this subject.

You can order the short gears from any Acura dealer, however, most do not know what to order.

We offer both the short gear and R&P gearsets at the best prices I am aware of.
http://www.scienceofspeed.com/products/drivetrain_performance_products/NSX/gears_LSD.asp

Cheers,
-- Chris

------------------
Revolutionize your NSX with ScienceofSpeed
www.ScienceofSpeed.com | [email protected] | 877-863-4520
 
I recently (1 week) bought the honda short gears from SOS. I like it alot and the customer service was second to none. I feel a huge differencs in the time it takes to get to 70 MPH. Although this is subjective, I feel the car is a lot faster.

In my opinion, since the ratio of the honda short second gear is closer to the ratio of the first gear, the engine stays in the sweet spot. The ratio of the stock second compared to the first is not as close and causes the rpm to drop lower.
 
Originally posted by Smoothaccel:
I feel a huge differencs in the time it takes to get to 70 MPH. Although this is subjective, I feel the car is a lot faster.
Click to expand...

Per Bob Butler, the short gears are quicker from 0 to 70 by 0.3 second (6.3 seconds vs 6.6 seconds). Above 70 mph, the stock gears are slightly quicker.
 
Okay, I'll bite.
wink.gif


Originally posted by Smoothaccel:
In my opinion, since the ratio of the honda short second gear is closer to the ratio of the first gear, the engine stays in the sweet spot. The ratio of the stock second compared to the first is not as close and causes the rpm to drop lower.
Click to expand...

This is not why the NSX accelerates faster with the short gears.

Acceleration is a function of torque at the wheels. The more torque at the wheels, the faster the acceleration. And torque at the wheels is simply engine torque, times gearing.

The torque curve of the NSX engine is quite flat:

97nsxpowercurve.gif


As you can see, the torque within any gear is not higher above the VTEC crossover point of 6000 RPM than it is below that. There is no "sweet spot" there. What VTEC does is keep the torque curve level, rather than dropping off, as revs continue to rise. It creates the perception of greater power because the engine is louder, but that is merely perception, not actual increased acceleration.

Remember, torque at the wheels is engine torque times gearing. The reason that the short gears create faster acceleration is because of gearing, not because of greater engine torque. When the gear ratios are closer together, you don't lose as much power due to gearing when you upshift as you do when they are further apart.
 
The short gears make the car accelerate faster, especially the 1-2. But I take it(anyone correct me if Im wrong) that the gearing would still be for a top speed of 186 mph like the stock gearing..until you change the R&P?
 
Originally posted by Redeye:
I take it(anyone correct me if Im wrong) that the gearing would still be for a top speed of 186 mph like the stock gearing..until you change the R&P?
Click to expand...

That's correct. Remember, the short gears only replace gears two through four. Fifth gear is left the same, so there is no change in performance in fifth gear with the short gears.
 
Originally posted by nsxtasy:
Okay, I'll bite.
wink.gif


This is not why the NSX accelerates faster with the short gears.

Acceleration is a function of torque at the wheels. The more torque at the wheels, the faster the acceleration. And torque at the wheels is simply engine torque, times gearing.

The torque curve of the NSX engine is quite flat:

97nsxpowercurve.gif


As you can see, the torque within any gear is not higher above the VTEC crossover point of 6000 RPM than it is below that. There is no "sweet spot" there. What VTEC does is keep the torque curve level, rather than dropping off, as revs continue to rise. It creates the perception of greater power because the engine is louder, but that is merely perception, not actual increased acceleration.

Remember, torque at the wheels is engine torque times gearing. The reason that the short gears create faster acceleration is because of gearing, not because of greater engine torque. When the gear ratios are closer together, you don't lose as much power due to gearing when you upshift as you do when they are further apart.
Click to expand...

Quote:_______________________________________
Per Bob Butler, the short gears are quicker from 0 to 70 by 0.3 second (6.3 seconds vs 6.6 seconds). Above 70 mph, the stock gears are slightly quicker.

First, ignore my last post. Now you are argueing but your facts contradict your point. You are right about the acceleration and torque but..
As a result of the short second gear being "shorter", when you go from first to second you will drop to 5513 instead of 4413. Now draw a straight horizontal line at 4413rpm on the 97+ NSX for example. Now meas the space between the line at 5513rpm. It might be small but an eyeball figuer looks like 8 ft/lb of torque. That 8 extra torque does make a difference. Also, some modified cars also loose low end torque and this torque difference is even greater. As in my car. Per Bob Buttler .3 seconds is close to half a second. To me thats a lot Tell me if this helps
smile.gif
 
I mean 5013. Please substitute 5013 for all the 5513 in the previous post.

Courtesy SOS
shift US stock gears (4.06 R&P) Japanese short gears (4.06 R&P)
1-2 4433 RPM 5013 RPM
2-3 5698 RPM 5705 RPM
3-4 6262 RPM 5824 RPM
4-5 6284 RPM 5983 RPM
 
Originally posted by Redeye:
The short gears make the car accelerate faster, especially the 1-2. But I take it(anyone correct me if Im wrong) that the gearing would still be for a top speed of 186 mph like the stock gearing..until you change the R&P?
Click to expand...

anyone correct me if Im wrong, but i thought the max speed for the 91-01 nsx was 168 not 186.
 
Originally posted by Smoothaccel:
Now you are argueing but your facts contradict your point.
Click to expand...

Huh?
confused.gif


Originally posted by Smoothaccel:
It might be small but an eyeball figuer looks like 8 ft/lb of torque. That 8 extra torque does make a difference.
Click to expand...

Not as much difference as the gearing. That difference of 8 lb-ft is about 3 percent greater torque, giving 3 percent more torque at the wheels. The difference in the gear ratios is about 13 percent, giving 13 percent more torque at the wheels. That means that more than 80 percent of the improvement in acceleration (torque at the wheels) is due to the gearing change, rather than from greater force from the engine.

Originally posted by Smoothaccel:
Courtesy SOS
shift US stock gears (4.06 R&P) Japanese short gears (4.06 R&P)
1-2 4433 RPM 5013 RPM
2-3 5698 RPM 5705 RPM
3-4 6262 RPM 5824 RPM
4-5 6284 RPM 5983 RPM
Click to expand...

Those figures differ slightly from those in the FAQ:

1 -> 2 4499 5085
2 -> 3 5698 5738
3 -> 4 6289 5903
4 -> 5 6378 5971

I'm not sure why.

Originally posted by cpmoran:
i thought the max speed for the 91-01 nsx was 168 not 186.
Click to expand...

For a stock NSX, it is. The NSX top speed is drag limited. That means that the top speed (168 mph) is reached at a point (7226 RPM) below redline (in fifth gear). At this point, drag on the NSX prevents it from continuing to accelerate. If the NSX could accelerate to its 8000 RPM redline in fifth gear, then it would be going 186 mph. This might occur, for example, if forced induction mods gave it enough power to continue overpowering the drag all the way up to redline.

[This message has been edited by nsxtasy (edited 22 November 2002).]
 
Originally posted by nsxtasy:
For a stock NSX, it is. The NSX top speed is drag limited. That means that the top speed (168 mph) is reached at a point (7226 RPM) below redline (in fifth gear). At this point, drag on the NSX prevents it from continuing to accelerate. If the NSX could accelerate to its 8000 RPM redline in fifth gear, then it would be going 186 mph. This might occur, for example, if forced induction mods gave it enough power to continue overpowering the drag all the way up to redline.

[This message has been edited by nsxtasy (edited 22 November 2002).]
Click to expand...

How much power is required to hit the 186? Anyone know? Do the comptech and BBSC give it enough?
 
Yes, a quick back-of-the-envelope estimate indicates the 5-6 PSI forced induction 5-speeds should in theory be able to hit redline in 5th gear.
 

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