Final drive LSD for 95/96 advice needed

[NSXnZ]

Love my car…I do mostly canyon/local twisty road driving and I’m mostly in 2nd gear…just one minor thing I wish I could change is the final drive, possibly short gears. I know the 95/96 5 speed 2nd gear isn’t as tall as 91-94…so, I’m not sure if that needs to be changed? Looking for as simple of final drive change for my model year whether it’s aftermarket LSD etc. I’m reading 95/96 needs additional items to make the change. Not even knowing what’s even available, could anyone let me know what would be the simplest way to accomplish this with parts availability in mind? A lot of info on prime is a few years old with parts that are no longer available. So, I’m looking to see what can be done these days. Cost isn’t really a limiting factor if that helps. TIA.

 

[MotorMouth93]

The 4.23 FD as you said is problematic on 95+ cars since they use a different differential design which won't work with the 4.23 ring gear, so you either have to get an aftermarket differential, find someone with a 91-94 diff for sale (theres probably a few floating around, you could post in the NSX Facebook groups and the parts wanted section here), or buy the parts to build a diff from scratch.

 

[AlanS]

ive always wondered this for us 95/6 owners... had no clue that there would be potential complications!

 

[RYU]

I've honed my trans setup over the course of my 15 yr ownership. I'm now on my 5th and final version. Just saying, I've tried them all. My car has done thousands of Angeles Crest Drives. It now lives in Santa Barbara. This is just to give you some context of what I'm about to recommend.

IMO you are better off with short JDM gears on 1,2,3,4 with your stock final drive than your current gears with a 4.23 or 4.4 OSGiken or ATS LSD combo.

To further enhanced your canyon driving experience, For long high speed Twisties like ACH I like the JDM gears with a 4.23 or stock 4.06. For tighter canyons like Malibu, Ojai, Alice's you can also enjoy 4.23 and 4.4. I have a friend who has a 6 spd 4.4 and loves it on ACH so there's no really wrong answer just preferences.

I'm now I'm on a Wavetrac LSD with a 6spd on a Type R 4.23 final drive. It's my ultimate setup and it's here to stay for the driving conditions this car sees.

Now, can you find the JDM gears in stock? They've been backordered forever.

 

[RYU]

Just to add... For the long sweeping canyons your need for an LSD is minimal. It's the tight stuff where an LSD really shines.

 

[NSXnZ]

Just to add... For the long sweeping canyons your need for an LSD is minimal. It's the tight stuff where an LSD really shines.

Thanks for all that info! I almost jumped on your NSX-r gearbox you had up for sale a few months ago and now regret it. Lol. I did just order the gear set through Amayama over the weekend and they did do the stock check and approve my order for the entire set of parts I need for JDM short gears. ETA range is long but I’m glad they are willing to source them. Couple other vendors basically told me to get in line and wait a long long time.

I’ve done a lot of reading on prime and it seems the 95/96 are the two oddball years with mix and match parts. I’m reading 4.23 NSX-R final drive works with EPS for most folks but SOS threads say it doesn’t. Their website is confusing on this also. I probably should just give them a call. Either way, I would need a diff off a 91-94 to install that FD or buy an aftermarket diff. I did find some KSP and OS Giken LSD kit with all the necessary install parts which might be perfect since I can’t seem to just find a diff off 91-94. Price of old diff plus parts might come close to aftermarket kit. KSP kit seems to claim minimal low speed noise as their headline. I could just try the short gears first but would hate to open the transmission again etc.

 

[Honcho]

Thanks for all that info! I almost jumped on your NSX-r gearbox you had up for sale a few months ago and now regret it. Lol. I did just order the gear set through Amayama over the weekend and they did do the stock check and approve my order for the entire set of parts I need for JDM short gears. ETA range is long but I’m glad they are willing to source them. Couple other vendors basically told me to get in line and wait a long long time.

I’ve done a lot of reading on prime and it seems the 95/96 are the two oddball years with mix and match parts. I’m reading 4.23 NSX-R final drive works with EPS for most folks but SOS threads say it doesn’t. Their website is confusing on this also. I probably should just give them a call. Either way, I would need a diff off a 91-94 to install that FD or buy an aftermarket diff. I did find some KSP and OS Giken LSD kit with all the necessary install parts which might be perfect since I can’t seem to just find a diff off 91-94. Price of old diff plus parts might come close to aftermarket kit. KSP kit seems to claim minimal low speed noise as their headline. I could just try the short gears first but would hate to open the transmission again etc.

Open secret - the 91-94 AT differentials are the same as the MT. It's a cheap way to pick one up- just find a junked AT box at a scrapyard.

 

[NSXnZ]

Open secret - the 91-94 AT differentials are the same as the MT. It's a cheap way to pick one up- just find a junked AT box at a scrapyard.

Nice to know! Before I spent $3k on a lsd kit, I’ll look for one of those first. Thanks.

 

[RYU]

Thanks for all that info! I almost jumped on your NSX-r gearbox you had up for sale a few months ago and now regret it. Lol. I did just order the gear set through Amayama over the weekend and they did do the stock check and approve my order for the entire set of parts I need for JDM short gears. ETA range is long but I’m glad they are willing to source them. Couple other vendors basically told me to get in line and wait a long long time.

I’ve done a lot of reading on prime and it seems the 95/96 are the two oddball years with mix and match parts. I’m reading 4.23 NSX-R final drive works with EPS for most folks but SOS threads say it doesn’t. Their website is confusing on this also. I probably should just give them a call. Either way, I would need a diff off a 91-94 to install that FD or buy an aftermarket diff. I did find some KSP and OS Giken LSD kit with all the necessary install parts which might be perfect since I can’t seem to just find a diff off 91-94. Price of old diff plus parts might come close to aftermarket kit. KSP kit seems to claim minimal low speed noise as their headline. I could just try the short gears first but would hate to open the transmission again etc.

Did Amayama give you a concrete date of arrival? My fear with them (and any vendor for that matter) is that they'll quote you a date and just keep pushing it back and back and back. You're left with a stockpile of like a hundred random parts but missing that key 1 or 2 pieces before you can start! I think that's the case with the JDM 2nd gear right now. Seems like forever that thing has been backordered.

If you're looking to spend money on an entire diff, if I was in your shoes, i'd consider buying the ATS Diff assembly which comes with the parts you need for a shorter final and a nice clutch type LSD. I had an OS Giken for a while and it's not really that street friendly but performed amazingly well, yet i've heard the ATS carbon disc version is quiet and possibly still available in a 4.23 or 4.4.
@MotorMouth93 knows the deets between the tranny differences, I do not so I can't speak especially to the 95/96 nuances. That was a bit of a transitional time period for the NSX.

 

[RYU]

i'd be curious how a USDM long gear setup work with a 4.4 short final. It might actually not be all that bad TBH. You just will have a short 5th gear cruising gear. I dunno... just something to consider I guess.