nsx-r diff conversion

mrbozo1 · 2 May 2012

This DIY is NOT for everyone,but with that said, if you have your trans out and you are rebuilding it or a shop is rebuilding it ,it does not cost much more to do this upgrade and is well worth it. Here is the vid I made when I converted my diff to a NSX-R diff. Hope it helps someone.. Also special thanks to LarryB who helped when I needed <iframe width="420" height="315" src="http://www.youtube.com/embed/tn2oF8rT6io" frameborder="0" allowfullscreen></iframe>

RYU · 2 May 2012

You sir are my hero. Thanks for posting this.

Wiki material here...

Grimeas · 2 May 2012

Great Info thanks for taking the time to do this

EAC · 2 May 2012

Awesome!

goldNSX · 2 May 2012

Thanks, I'll need this in the near future.

TURBO2GO · 2 May 2012

I am not sure I know this... what exactly is the difference between the standard and the R?

Honcho · 2 May 2012

TURBO2GO said:
I am not sure I know this... what exactly is the difference between the standard and the R?

The standard "unlocks" at about 50 lb/ft of torque. The R unlocks at a little over 100. Essentially, it keeps the rear wheels locked together longer, so you have more power to the outside wheel when coming out of a corner. I have this mod and I love it, though it is only apparent under very spirited driving.

I1O101I · 3 May 2012

mrbozo1 said:
here is a vid I made when I converted my diff to a NSX-R diff. Hope it helps someone.. Also special thanks to LarryB who helped when I needed <iframe width="420" height="315" src="http://www.youtube.com/embed/tn2oF8rT6io" frameborder="0" allowfullscreen></iframe>

Does this conversion only work on a LSD 6speed also? or only on the 5 speed LSD

Bryan

TURBO2GO · 3 May 2012

Honcho said:
The standard "unlocks" at about 50 lb/ft of torque. The R unlocks at a little over 100. Essentially, it keeps the rear wheels locked together longer, so you have more power to the outside wheel when coming out of a corner. I have this mod and I love it, though it is only apparent under very spirited driving.

Why didn't Honda make them all this way?

dpnsx · 3 May 2012

TURBO2GO said:
Why didn't Honda make them all this way?

Accelerated tire wear, I'd imagine. If the diff spends more time locked up, then you spend more time scrubbing the inside tire through the corners.

Nero Tenebre · 3 May 2012

I1O101I said:
Does this conversion only work on a LSD 6speed also? or only on the 5 speed LSD

Bryan

The type r differential is actually a 5 spd diff since the regular 6 spd is not compatible w power steering. Not sure about the shimming but I think you can shim either one.

EdinKali · 3 May 2012

Thanks for posting the video! Very informative.

Honcho · 3 May 2012

TURBO2GO said:
Why didn't Honda make them all this way?

I believe it was a "comfort" issue. Supposedly, the tighter lockup makes the car harder to turn during very slow maneuvering, i.e., parking. The NSX-R was designed as a "track day" NSX, so the primary concern was performance, not comfort. Some people claim to be able to feel the diffeerence during parking. I can't.

Nero Tenebre said:
The type r differential is actually a 5 spd diff since the regular 6 spd is not compatible w power steering. Not sure about the shimming but I think you can shim either one.

The 6-speed Diff first appeared in the 95+ 5-speeds. It is a helical, torsen type diff, unlike the 91-94 model, which is a spring-loaded clutch. Thus, there is no need to shim the 6-speed diff because it is gear-driven. Unlike the spring-loaded clutch, which only has one preset breakaway, the helical version locks tighter as you turn harder,meaning you end up with likely more than 100 lb/ft of breakaway at track speeds. I think it is a superior design and Honda claims 10% better corner exit speed (compared to the stock NA1)

Nero Tenebre · 3 May 2012

Honcho said:
I believe it was a "comfort" issue. Supposedly, the tighter lockup makes the car harder to turn during very slow maneuvering, i.e., parking. The NSX-R was designed as a "track day" NSX, so the primary concern was performance, not comfort. Some people claim to be able to feel the diffeerence during parking. I can't.

The 6-speed Diff first appeared in the 95+ 5-speeds. It is a helical, torsen type diff, unlike the 91-94 model, which is a spring-loaded clutch. Thus, there is no need to shim the 6-speed diff because it is gear-driven. Unlike the spring-loaded clutch, which only has one preset breakaway, the helical version locks tighter as you turn harder,meaning you end up with likely more than 100 lb/ft of breakaway at track speeds. I think it is a superior design and Honda claims 10% better corner exit speed (compared to the stock NA1)

Man good to know honcho! I read that in my little guide about changes for the 95 model year (corner exit speed increased by 10% due to new diff) but I didn't know they kept using it for the consequent years.

TURBO2GO · 3 May 2012

Yes thanks for clearing that up Honcho.

Chris NSX · 4 May 2012

I1O101I said:
Does this conversion only work on a LSD 6speed also? or only on the 5 speed LSD

Bryan

Bryan, you should know the answer.http://www.nsxprime.com/forum/showpost.php?p=872498&postcount=95

I had to use a 5 speed differential with the 6-spd NSX-R 4.23 in my new 6 speed transmission. I also add the NSX-R Input Shaft so I can use the older twin disc clutches.

Nero Tenebre · 4 May 2012

Chris how do you like that setup? I was going to do the same thing but I am rethinking it.

Chris NSX · 4 May 2012

Nero Tenebre said:
Chris how do you like that setup? I was going to do the same thing but I am rethinking it.

I guess, I have to love this setup due to the cost of a 6 speed trans, NSX-R 4.23 twin imput shaft.

Really I don't think the performance gains outweigh the cost of this upgrade. When I did this transmission, there weren't much options for clutches for the 6 speed trans. My options were stock, RPS and Comptech and the pedal feel was too firm for me. That's why I went with the NSX-R twin imput shaft.

I had a Comptech clutch in my first NSX and it sucks driving in traffic.

You will need to source a 91-94 5 speed diff to do NSX-R 4.23 in a 6speed transmission.

goldNSX · 4 May 2012

A different question to those who opened the diff and had a sight on the diff clutch discs: how many miles do they last? Did anybody have to change them?

Sylvan · 4 May 2012

Very cool. So all that is needed are the two parts that you mention in the video? Where can they be obtained, and are they expensive? I might like to do this if I pull my trans to upgrade to the short gears and 4.23 final drive.

mrbozo1 · 4 May 2012

Sylvan said:
Very cool. So all that is needed are the two parts that you mention in the video? Where can they be obtained, and are they expensive? I might like to do this if I pull my trans to upgrade to the short gears and 4.23 final drive.

You can get the parts at SOS for around 100 bucks. Most dealers wont have the parts that end in J00 as these are JDM parts. The part numbers are listed in the video.

Honcho · 4 May 2012

goldNSX said:
A different question to those who opened the diff and had a sight on the diff clutch discs: how many miles do they last? Did anybody have to change them?

Apparently a very long time. Before we opened my diff- we tested the breakaway and it was well within spec. The discs looked fine with plenty of life left. My diff had ~80,000 miles at the time. I think an important thing to note is that Honda OEM MTF probably helps with the wear.

fenixv8 · 4 May 2012

Sigh I just did the short gears and final drive. Guess I gotta open up the tranny again

mrbozo1 · 5 May 2012

goldNSX said:
A different question to those who opened the diff and had a sight on the diff clutch discs: how many miles do they last? Did anybody have to change them?

That diff that you see in the video has 130000 miles on it and you can see no wear on the clutches.I certainly think that Honda overbuilt this part of the car.

96cxt · 16 December 2020

Back from the dead. Thank you for the video.

I broke the snap ring in my 92 a few weeks ago. I had already replaced the transmission about 8+ years ago with one that had all the JDM gears and typeR FD.
I was able to source a new casing and so I'm not sure if this transmission also had the TypeR differential conversion already done to it.
Since I have to open up the transmission, might as well buy the conversion kit and have it ready.

nsx-r diff conversion

Similar threads