LSD differences - which one is the best and why?

The NSX has been made with, as far as I know, two different Limited Slip Differentials (LSD), the first in the NA1 1991-1996 models, and the one in the NA2 1997-2005 models.
Apart, from that, OS Giken also made a different LSD for the NSX.

As I understand it, a LSD gives a car extra traction on the inside wheel in a turn and therefore higher corner exit speeds.
Could anyone explain what the exact differences are between the various differenct LSD's of the NSX and which one is the best and why ??

Unless you track your car I couldn't justify the money for a Giken FD. You can easily go to the Type R differential by adding some (quite cheap) parts. But my arguments are from an economical point of view only. :wink:

they changed it in 95 to a different version (for the non-automatic cars)

"Limited Slip Differential Changes on manual transmission cars. Went from Torque Control Ddifferential to a Torque Reactive Differential - when combined with Throttle-By-Wire, increases speeds out of a corner by 10%. Automatic cars keep old differential."

All manual NSXs have LSD standard. I have no idea about the autos. 5 speeds are a standard clutch type LSD. 6 speeds are a version of the same with a helical gear that varies the disk pressure based on the power you are putting into it. The NSX-R diff is a 5 speed diff with a higher preload - a pita to park but good on the track.

As I understand it the OSG is a friction plate LSD as well, again with a high preload for the track.

All friction disk diffs lose effectivness as they wear. I have no ideal how long this takes on the NSX. For street driving many people prefer a torsen/worm drive differential as they do not wear surfaces but rather have gears. I am not aware of any torsen diffs that are made in the aftermarket for the NSX.

MJK said:

All manual NSXs have LSD standard. I have no idea about the autos. 5 speeds are a standard clutch type LSD. 6 speeds are a version of the same with a helical gear that varies the disk pressure based on the power you are putting into it. The NSX-R diff is a 5 speed diff with a higher preload - a pita to park but good on the track.

As I understand it the OSG is a friction plate LSD as well, again with a high preload for the track.

Click to expand...

Ok, all this is and was known to me already.
So, my question is now, if Honda chose to go back to the 5-speed LSD on the NSX-R (like they also went back to the pre-1997 two-disc clutch type), does this mean that they figured the original LSD is/was better than the later type?
Or are the other reasons as well ??

I am not sure why they went back. A helical gear was probably a non-factor for a racing version - so no penalty for going back in their eyes. A high preload all the time would be perfect on the track. Are there other considerations or advantages to it? Not that I am aware of, but I am certainly not an expert.

I have read that the 4.23 does not work with the 6 speed LSD. I am not sure if that is true or not. If that was a carryover part perhaps it has something to do with it? Is the 5 speed LSD lighter or more efficient? I honestly don't know.

Hopefully someone who has travelled this road like Dave, Shad or Kip can pipe up.

As for the twin disk clutch, lower MOI is better.

I think there is a wrong assumption here about going "back". NSX-R did not change like US model 1995's did.

US Models:

1991-1994 LSD straight tooth inner gear in dif
1995+ Torque sensing LSD helical inner gear in dif

If you want to go to an NSX-R dif in any NSX, you must have the 1991-94 dif which will mate with the NSX-R 4.23 ring gear. They never made a 4.23 to go with the 1995+ dif.

Which is better...... would be a matter of opinion, and since opinions are free, I am sure you will get many.

If you want a 4.23 in a six speed, you MUST back-date the dif, end of story, and yes it will function properly in a 6 speed trans. There has been one report of an issue with the power steering when installing the 4.23 in a six speed in a late model car (1997+), I have not had a oppurtunity to confirm this personally.

HTH,
LarryB

MJK said:

I am not sure why they went back. A helical gear was probably a non-factor for a racing version - so no penalty for going back in their eyes. A high preload all the time would be perfect on the track. Are there other considerations or advantages to it? Not that I am aware of, but I am certainly not an expert.

I have read that the 4.23 does not work with the 6 speed LSD. I am not sure if that is true or not. If that was a carryover part perhaps it has something to do with it? Is the 5 speed LSD lighter or more efficient? I honestly don't know.

Hopefully someone who has travelled this road like Dave, Shad or Kip can pipe up.

As for the twin disk clutch, lower MOI is better.

Click to expand...

I have the 4.23 with a 6 speed on my 2001 so it does fit.

MvM said:

*snip*

As I understand it, a LSD gives a car extra traction on the inside wheel in a turn and therefore higher corner exit speeds.

Click to expand...

Actually, an LSD prevents all the torque from going to a single wheel. In a turn, the inside wheel has less weight on it so it is likely to spin if it gets all the torque. LSDs make it more even between the drive wheels and, therefore, gives torque to the outside drive wheel.

A sign of a failing LSD is the inside drive wheel spinning under hard acceleration in a turn.

FYI
These are photos of my old parts but the boxes of the new parts.
The guy I purchased them from is in New York. I think he is the U.S. distributor for the Japanese company. I have all the paperwork somewhere but this is on my 2001 NSX and I Have no signal modifier on it I am running a TEC-3 computer because of my SC. They are the 4.23 LSD. I think something like 1:5 way? not sure.

ken sampson said:

FYI
These are photos of my old parts but the boxes of the new parts.
The guy I purchased them from is in New York. I think he is the U.S. distributor for the Japanese company. I have all the paperwork somewhere but this is on my 2001 NSX and I Have no signal modifier on it I am running a TEC-3 computer because of my SC. They are the 4.23 LSD. I think something like 1:5 way? not sure.

Click to expand...

See the attached photos.

Ok now I know what brand I have its a ATS LSD
http://www.a-t-s.co.jp/02lsd/carbon/index.html
Mine is a carbon fiber type so it does not need a signal modifier.
Also see.http://www.a-t-s-usa.com/carbon-development.shtml