I don't understand
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Would love some opinions on 4.55 R&P upgrade only
- Thread starter ilya
- Start date
I don't understand
Originally posted by ak:
I don't understandIs the torque on the OEM LSD something that you can change/control? I know that the TypeRs came with different torque spec....but did they come with the same LSD? ???
The torque can be changed on the OEM LSD by adding/removing shims. That's about the extent of my knowledge with this subject. I believe (about 85% sure) the TypeR uses the same differential shimmed to a different torque value. I know that mine was set to the TypeR spec (not sure what it is) when my R&P was changed. To be honest, I really couldn’t tell any seat-of-the-pants difference on the street or track between the OEM setting and the TypeR setting. It would be nice if someone with vast experience in this area would chime in (hint, hint MarkB)
DanO
- Joined
- 3 February 2000
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You basically add a second spring plate to your LSD to get the Type-R setup. The OEM LSD spec is so wide it's a joke, something like 40-100 lbs. Most cars checked fall into the lower part of that range, maybe 60. You'll probably end up at 100+ with the secondary spring plate in there.
It just keeps your rear wheels locked together more. So if there is a corner at the track you have taken to not throttling through as hard as you otherwise would because you were getting light on the inside and spinning the inside rear wheel, you should be able to go through faster since the wheels are more locked together with the tightened LSD. There is no benefit for straight line or normal street driving.
It just keeps your rear wheels locked together more. So if there is a corner at the track you have taken to not throttling through as hard as you otherwise would because you were getting light on the inside and spinning the inside rear wheel, you should be able to go through faster since the wheels are more locked together with the tightened LSD. There is no benefit for straight line or normal street driving.
If you guys want to see what any kind of modification does (including gear changes, hp changes, torque changes, and more) log on to www.cartest2000 and spring for 50 bucks for the best analysis tool you've ever seen!
For example, a stock 91 NSX ran 14.0 at 103 in the 1/4. With a 4.55 it ran 13.9 at 101! Why? because an additional shift to 4th was required through the 1/4 mile.
I use this tool all the time to evaluate modifications. For example, I found that the 1/4 mile times would improve in my normally aspirated 98 coupe by adding the 4.55. However, if I added a supercharger, the 1/4 mile times would be hurt because I would have to use 5th gear to complete the 1/4 mile!
By the way, I don't work for CarTest. I've just found it to be a great tool.
For example, a stock 91 NSX ran 14.0 at 103 in the 1/4. With a 4.55 it ran 13.9 at 101! Why? because an additional shift to 4th was required through the 1/4 mile.
I use this tool all the time to evaluate modifications. For example, I found that the 1/4 mile times would improve in my normally aspirated 98 coupe by adding the 4.55. However, if I added a supercharger, the 1/4 mile times would be hurt because I would have to use 5th gear to complete the 1/4 mile!
By the way, I don't work for CarTest. I've just found it to be a great tool.
That information would support the reason I was sold the 4.55 R&P in the first place. It was actually hurting the 1/4 mile time of a certain turbo in Texas and he needed the stock R&P.
Lucky for me.
Lucky for me.
I have a 91 with exaust,header,intake and a 70 shot nos... Will the 4.55 help or hurt my 1/4 mile times?
I have a 91 with exaust,header,intake and a 70 shot nos... Will the 4.55 help or hurt my 1/4 mile times?
What are they now? Are you close to running out of revs in third gear, or are you already forced to upshift to fourth?
If your current gears are stock, you run out of third gear at 114 mph. If you change to the 4.55 R&P, you will run out of third at 102 mph. Adding the time to upshift to fourth could hamper your 1/4 mile times.
What are they now? Are you close to running out of revs in third gear, or are you already forced to upshift to fourth?
If your current gears are stock, you run out of third gear at 114 mph. If you change to the 4.55 R&P, you will run out of third at 102 mph. Adding the time to upshift to fourth could hamper your 1/4 mile times.
My gears are stock. I can see the concept of the gearchange to 4th but what about the 1-2 shift? Does that compinsate, and what happens when the traps exceed 114?
My gears are stock. I can see the concept of the gearchange to 4th but what about the 1-2 shift?
What about it? It will happen at a lower speed, but you will still need to shift. It takes longer to do three upshifts than to do two upshifts, and you're not likely to gain enough during the acceleration to make up for the time lost during the extra upshift. That's why David didn't want the 4.55 R&P.
what happens when the traps exceed 114?
You will need to upshift to fourth at 114 (with the stock gears) or at 102 (with the 4.55 R&P) because you will be at redline.
Maybe I didn't understand your question?
What about it? It will happen at a lower speed, but you will still need to shift. It takes longer to do three upshifts than to do two upshifts, and you're not likely to gain enough during the acceleration to make up for the time lost during the extra upshift. That's why David didn't want the 4.55 R&P.
what happens when the traps exceed 114?
You will need to upshift to fourth at 114 (with the stock gears) or at 102 (with the 4.55 R&P) because you will be at redline.
Maybe I didn't understand your question?
What I meant was that if the traps are 118 I will cross the traps at a lower rpm in the stock vs the 4.55? So your saying it won't help?
If you are already getting up to 118 mph with the stock gears, you will be shifting to fourth with either set of gearing. In that case, the 4.55 R&P should improve your 1/4 mile times, assuming it doesn't take you above 128 mph where you would again need an additional upshift, this time to fifth.
[This message has been edited by nsxtasy (edited 06 November 2001).]
[This message has been edited by nsxtasy (edited 06 November 2001).]
Are you currently getting 118 mph traps w/only a 70 shot? ( meaning only a 70 I saw you had other bolt ons) Not implying that you aren't, just curious.
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Jason
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Jason
I just noticed another 4.55 R&P on ebay starting at $880 with no reserve.
http://cgi.ebay.com/ebaymotors/aw-cgi/eBayISAPI.dll?ViewItem&item=597668463
Don't know anything about it, but thought I'd mention it in case anyone else is looking for a good deal on one. What are the chances? Two of them coming up for sale in a matter of weeks!
http://cgi.ebay.com/ebaymotors/aw-cgi/eBayISAPI.dll?ViewItem&item=597668463
Don't know anything about it, but thought I'd mention it in case anyone else is looking for a good deal on one. What are the chances? Two of them coming up for sale in a matter of weeks!
