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LSD questions

Joined
31 January 2008
Messages
541
Location
Wellington, New Zealand
Hi guys,

We're getting close to being able to get our race car to the track and realised that I didn't get around to investigating the factory LSD limits and whether I need to put off the cars first track test or not.

I'm assuming that the factory LSD will be "acceptable" to a certain degree for shaking the car down and making sure everything works OK, but maybe not up to the job once we start getting serious ??

Or does the factory LSD cope just fine ?? I'm assuming that once we turbo the car we will have no choice but to replace, but really wondering about if we will get away with what we have for now till I can source an OSGiken or similar.

From what I've read so far the OSGiken LSD is the item of choice.......

Anyone have any comments, suggestions or experiences they would like to share regarding the above ?

And last but not least, does anyone have anything suitable available for purchase ?
 
I don't track my NSX but did have 430rwhp/300rwtq prior to my engine build with a SOS S/C.

I'm running Amsoil Syncromesh and love it.

No noise, shifting is like silk and my LSD still works wonders laying rubber on both rear tires even though there are theories, ideas, suggestions that it may not be the right fluid.

http://www.nsxprime.com/forum/showthread.php?t=137395

http://nsxprime.com/forum/showthread.php?t=149181

http://www.nsxprime.com/forum/showthread.php?t=144752



I did look at the O/S Giken solution and the 2 things that made me hold off were:

1. it seems to require a thicker grade of oil like 80w(?) which makes me wonder if that will make the shifting notchier
2. I've heard that the O/S Giken is noisier (I won't mention which NSX vendor(s) told me this) and the driving experience for street usage isn't as pleasant as OEM
 
I, personally, wouldn't scrap any testing time to swap the unit out. But as you say getting serious in the future that you'll likely want something a little more capable. My motor has 60k with just over stock power and a lighter drive train on r-comps, etc. I track it about 2-3 times a month and now that i've got the set up pretty dialed and driving it much more aggressively (i.e power sooner more sliding) I've really started to feel the LSD and being a weak link. It feels to me very similar to a viscus unit or a worn out clutch type when really on it. Ive got a few on-board videos of some hotlaps and you can hear, quite clearly, the power balk when im on the throttle hard coming out of turns. (TCS removed)

Its not tire spin but rather feels like power loss to the 'outside' rear tire thats under load. Once it reaches an equilibrium as the cars settles you can hear the revs change and rise linearly again. My next serious upgrade is certainly going to be LSD and final drive. This happens primary on tracks like Streets of willow and 'onramp' at Buttonwillow
 
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Thanks for the reply....

At least for the first tests and first few events we were planning on keeping the car N/A to concentrate on getting the car handling, stopping and generally bedding in the car and any other issues we might have and then once we're happy with it, we are going to turbocharge it.

So for now if we can get away with using the stock unit then we can look at the OS Giken unit once we've got that stage of things out of the way, but I just didn't want to get used to the car with a stock diff and then find that using the OS Giken dramatically changes the feel of the car........... if it just calms down some of the nasty "on the edge" handling and turn in then that will be fine, I just don't want it to be completely different or I would rather have it from the start if that makes sense.

Hard to know if you would notice the difference as much on the street as the track but I guess that's what I'm asking from those who have used both...

Thanks for all replies as always.

Illwillem, I was responding to the reply above yours whilst you were posting............. your reply is exactly what I was after / hoping to hear............ Sounds like the OS Giken will just be an extension of the stock LSD not a major change so that is great news as I didn't want to hold up testing as we're well behind schedule anyhow. I will just save my $'s and get one in the next few months and get it in there when I can. thanks heaps for the reply. Any other opinions are welcomed also, as I know many people have many different experiences.
 
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There is the NSX-R differential mod that someone recently posted a DIY on. I believe it makes the LSD harder to slip but that's about all i know
 
Yes you can shim the 91-94 5spd diff to R spec, but if you have 95+ diff that's already upgraded to allow 10% more corner exit speed according to Honda.
 
There is the NSX-R differential mod that someone recently posted a DIY on. I believe it makes the LSD harder to slip but that's about all i know
Here is the link that I posted about the lsd http://www.nsxprime.com/forum/showthread.php?t=161057 When I did mine I gained about 75% more breakaway force or about 150 ft lbs of force that it takes to slip the clutches in the diff. This is not for everyone but it is a very good upgrade for not a lot of money if you are able to do it yourself. This mod is good only for the 5 speed trans as I understand the 6 speed is quite different and wont require this mod.
 
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95 and 96 5 speeds have the 6 speed diff, just to be clear
 
Thanks for the feedback........... sounds like we can get away with doing our primary shakedowns and testing with what we have and then I will get my A into G and source an OSGiken unit before we move too far forward.

Considering we are NA now, but planning on Turbo charging once the car has been settled in and shakedown completed, would you still suggest the 4.4 final drive ?? I'd have assumed it was going to make more sense for us to stick with the 4.06 ??

Although we're based here in New Zealand, the 5 speed box we have was sourced out of the states which I think has slightly different gearing to the JDM set ......
 
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Thanks for the feedback........... sounds like we can get away with doing our primary shakedowns and testing with what we have and then I will get my A into G and source an OSGiken unit before we move too far forward.

Considering we are NA now, but planning on Turbo charging once the car has been settled in and shakedown completed, would you still suggest the 4.4 final drive ?? I'd have assumed it was going to make more sense for us to stick with the 4.06 ??

Although we're based here, the 5 speed box we have was sourced out of the states which I think has slightly different gearing to the JDM set ......
I would check with V8killer as he has been down that road.
 
Thanks for the feedback........... sounds like we can get away with doing our primary shakedowns and testing with what we have and then I will get my A into G and source an OSGiken unit before we move too far forward.

Considering we are NA now, but planning on Turbo charging once the car has been settled in and shakedown completed, would you still suggest the 4.4 final drive ?? I'd have assumed it was going to make more sense for us to stick with the 4.06 ??

Although we're based here in New Zealand, the 5 speed box we have was sourced out of the states which I think has slightly different gearing to the JDM set ......
Get the jdm gear stack and if you dont go to tracks above 160mph, go with 4.40
 
Thanks Billy.

There is only 1 track in the country that I would expect to get up around the 160mph mark on and I'm not likely to get up there very often at all and even if I did, I think the 160mph would be enough so I will take your advice and get the 4.4 setup.

Thanks again mate.......always helpful and willing to share info with us lesser track racing plebs !! :D
 
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