Need to replace clutch. Which one should I get?

[e9coupe]

91 with a bad clutch. It's been sitting in storage for years and I'll be getting to it later this year (I hope), but I want to start getting parts together. Everything is stock, I only drive on the street, I'm an old man so I'm not as hard on cars as I used to be. I've looked around for other clutch threads but they all seem to be kinda old or dealing with more HP. I'm thinking OEM or SOS 275. Any thoughts? I've seen comments about OEM parts not being available, etc. I'll be doing the work myself.

Dan
Sacramento, CA

 

[solidol]

Both OEM (unless cost is an issue) and SoS 275 (if they still sell them and not 350) are two of your best options.

PS: I'd still take SoS 350 over OEM.

 

[e9coupe]

Both OEM (unless cost is an issue) and SoS 275 (if they still sell them and not 350) are two of your best options.

PS: I'd still take SoS 350 over OEM.

They still show the 275 on their website. Is this based on personal experience or just an overall opinion from comments on this site? I feel kinda the same way and it seems like the SOS would be easier to install.

 

[solidol]

Personal experience.

* Tried messaging you directly but got error message saying you can't receive direct messages. DM me.

 

[neuronbob]

SOS 275 is your ticket if you are remaining stock.

If you have any inkling, any possible thought of adding power in the future, then get the 350, as it’s rated for 350+ ft-lb. I have the 350 on my SOS TT setup and the pedal effort is very minimally more than the stock clutch it replaced.

 

[drew]

Just get the friction disc's rebuilt.

I had a set done by Fort Wayne Clutch a while back..good.

 

[Honcho]

I still maintain the OEM clutch is the best option for a street driven NSX with no power adders. It's not harder to install than any other clutch if you remember to initialize it first.

 

[The King]

I still maintain the OEM clutch is the best option for a street driven NSX with no power adders. It's not harder to install than any other clutch if you remember to initialize it first.

I agree with this recommendation. I put a supposedly good aftermarket clutch in my S2000. Lasted a whole 15K km. Never abused, only street driven by old retired man. Do yourself a favour and get an OEM replacement. Needless to say that's what went back in the 2000.

 

[Honcho]

I agree with this recommendation. I put a supposedly good aftermarket clutch in my S2000. Lasted a whole 15K km. Never abused, only street driven by old retired man. Do yourself a favour and get an OEM replacement. Needless to say that's what went back in the 2000.

Yep. It's like one of those spider graphs for brake pads. In terms of longevity, ease of engagement and fitment, nothing really beats the OEM. But, [MENTION=5430]drew[/MENTION] makes a good point- you can just re-build the friction discs if they are in good shape and your mid-plate and pressure plate still are within spec.

 

[e9coupe]

Okay, I had decided to just go with the SOS 350 but now I'm not sure again. LOL My clutch was fine for the 4k miles I put on it after buying the car and it just barely started slipping when I decided to park the car. I also need to do the timing belt, rebuild the muffler, paint the top, yada yada. I would just replace the discs if that's a good option. I put 4k miles on the car in four years so I'm not that concerned about longevity, although my son will inherit the car at some point.

What are my options for just doing the discs? New or rebuilt? Would I ship mine to Fort Wayne Clutch or could I use a more local place and give them specs? This is great info guys.

 

[Honcho]

Okay, I had decided to just go with the SOS 350 but now I'm not sure again. LOL My clutch was fine for the 4k miles I put on it after buying the car and it just barely started slipping when I decided to park the car. I also need to do the timing belt, rebuild the muffler, paint the top, yada yada. I would just replace the discs if that's a good option. I put 4k miles on the car in four years so I'm not that concerned about longevity, although my son will inherit the car at some point.

What are my options for just doing the discs? New or rebuilt? Would I ship mine to Fort Wayne Clutch or could I use a more local place and give them specs? This is great info guys.

Just about any decent clutch shop can rebuild the discs. The service manual has the specs for measuring the flywheel and mid-plate: you just need a precision edge. If you don't want to go to all that trouble, you can order a complete clutch set from Marc at MITA Motorsports for a lot less than Acura is charging. Depending on the miles, you may also want to replace the clutch fork, release bearing and guide at the same time. These items (especially the fork) have a very significant impact on clutch feel and engagement.

 

[RYU]

If I was rebuilding your type of NSX my preferred setup would be the OEM clutch but with a Jun or Fidanza lightened OEM spec flywheel. The OEM pressure plate and clutch discs are top quality but the flywheel is a bit heavy, thought not nearly as bad as the dual mass flywheel in the stock 6 speed.

http://as-motorsport.com/site/en/ca...on-c-23/5mt-lightweight-flywheel-4-5-kg-p-412

 

[e9coupe]

Just about any decent clutch shop can rebuild the discs. The service manual has the specs for measuring the flywheel and mid-plate: you just need a precision edge. If you don't want to go to all that trouble, you can order a complete clutch set from Marc at MITA Motorsports for a lot less than Acura is charging. Depending on the miles, you may also want to replace the clutch fork, release bearing and guide at the same time. These items (especially the fork) have a very significant impact on clutch feel and engagement.

Thanks, all of that makes good sense. I don't know anything about clutch disc material. I'm assuming the shop will know if there's anything specific about NSX discs? I'm in the Sacramento area so I'll contact Capitol Clutch and Brake. They've been around forever.

BTW, I didn't like the feel of the soft engagement on the stock setup and have read there's a hydraulic dampening setup that can be bypassed. Is that correct?

 

[e9coupe]

If I was rebuilding your type of NSX my preferred setup would be the OEM clutch but with a Jun or Fidanza lightened OEM spec flywheel. The OEM pressure plate and clutch discs are top quality but the flywheel is a bit heavy, thought not nearly as bad as the dual mass flywheel in the stock 6 speed.

http://as-motorsport.com/site/en/ca...on-c-23/5mt-lightweight-flywheel-4-5-kg-p-412

Okay, you read my mind. That was the other part of using the SOS 350 that I liked. So I'd go with rebuilt OEM discs with this flywheel versus the SOS 350 kit that comes with a lightened flywheel. The price difference probably isn't enough to worry about so now I'm back to where I started. Although, I'm more confident now that either setup would work fine.

 

[Honcho]

Thanks, all of that makes good sense. I don't know anything about clutch disc material. I'm assuming the shop will know if there's anything specific about NSX discs? I'm in the Sacramento area so I'll contact Capitol Clutch and Brake. They've been around forever.

BTW, I didn't like the feel of the soft engagement on the stock setup and have read there's a hydraulic dampening setup that can be bypassed. Is that correct?

Okay, you read my mind. That was the other part of using the SOS 350 that I liked. So I'd go with rebuilt OEM discs with this flywheel versus the SOS 350 kit that comes with a lightened flywheel. The price difference probably isn't enough to worry about so now I'm back to where I started. Although, I'm more confident now that either setup would work fine.

I'm installing the OEM/Jun setup. Still waiting on my flywheel- backordered from Japan. Anyway, yes, you can use the NSX-R clutch damper assembly, which removes the rubber diaphragm from the system. It does create a more direct clutch engagement, but keep in mind it was designed for the RHD NSX-R clutch pedal, which has different pivot geometry from the "regular" NSX pedal. It may require some fiddling on pedal adjustment to ensure a complete clutch release. I'll tell you in a few weeks, as I am installing this setup.

 

[solidol]

Heavy OEM assembly is the only thing I don't like about OEM clutch, except the price and arguably unnecessary complexity of a twin.

This is mostly why I have recommended SOS. Not too light to loose moment of inertia too quickly, just perfect. 275 is basically without a penalty on engagement pressure, 350 with marginal increase bin pressure.

 

[e9coupe]

I'm installing the OEM/Jun setup. Still waiting on my flywheel- backordered from Japan. Anyway, yes, you can use the NSX-R clutch damper assembly, which removes the rubber diaphragm from the system. It does create a more direct clutch engagement, but keep in mind it was designed for the RHD NSX-R clutch pedal, which has different pivot geometry from the "regular" NSX pedal. It may require some fiddling on pedal adjustment to ensure a complete clutch release. I'll tell you in a few weeks, as I am installing this setup.

Nice! I doubt I'll get to mine until this summer so you'll probably be done by then. What's their ETA on the back order?

 

[e9coupe]

Heavy OEM assembly is the only thing I don't like about OEM clutch, except the price and arguably unnecessary complexity of a twin.

This is mostly why I have recommended SOS. Not too light to loose moment of inertia too quickly, just perfect. 275 is basically without a penalty on engagement pressure, 350 with marginal increase bin pressure.

I couldn't find a weight given for the the SOS flywheel, just an overall assembly weight. Any idea?

What I found:
Fidanza 191981: 7 lbs
JUN: 9.9 lbs
OEM: 15.4 lbs

The Fidanza's weight makes me a little nervous for a quasi daily driver.

 

[Honcho]

Nice! I doubt I'll get to mine until this summer so you'll probably be done by then. What's their ETA on the back order?

I ordered in November and they told me January

 

[solidol]

May have to call SOS to get weight number. I haven't checked mine. But suggest working off whole assembly not flywheel alone.

 

[e9coupe]

May have to call SOS to get weight number. I haven't checked mine. But suggest working off whole assembly not flywheel alone.

Oh yeah, that makes sense. I'm thinking it might be best to stick with something that's designed together as an assembly like the SOS kit than to piece it together. Back and forth I go. LOL I just don't want any problems.

 

[Lroy]

e9coupe, since you live in Sacramento (I live in Auburn) it might be worth reaching out to Shad Huntley at Driving Ambition in Rancho Cordova and ask his opinion on this. He's one of....if not the best NSX mechanics in the nation. He agrees that the stock clutch is your best bet overall. He also likes the Exedy clutch.
If you do opt for a factory clutch, MITA Motorsport had decent prices on them recently. You just need to pay for shipping which is pretty steep right now due to COVID.

 

[Honcho]

Oh yeah, that makes sense. I'm thinking it might be best to stick with something that's designed together as an assembly like the SOS kit than to piece it together. Back and forth I go. LOL I just don't want any problems.

e9coupe, since you live in Sacramento (I live in Auburn) it might be worth reaching out to Shad Huntley at Driving Ambition in Rancho Cordova and ask his opinion on this. He's one of....if not the best NSX mechanics in the nation. He agrees that the stock clutch is your best bet overall. He also likes the Exedy clutch.
If you do opt for a factory clutch, MITA Motorsport had decent prices on them recently. You just need to pay for shipping which is pretty steep right now due to COVID.

We must have put it out in the air- Evasive Motorsports called me today and it just shipped. Should have it by Monday. Remember, Jun makes two versions: a "Lightweight" (4.5 kg) and "Ultra-Lightweight" (4.3 kg). I got the lightweight.

Agree on Shad- he's had more experience with the Gen1 NSX than just about anybody in the U.S.

 

[RYU]

If you have big OEM parts purchases check these guys https://www.amayama.com/en/genuine-catalogs/honda

I don't know what shipping is like these days but I've found them to have crazy cheap prices.

Honda use to sell the clutch discs separately but I believe they now only sell the pressure plate, discs, and flywheel combo. Worth a check though.

 

[drew]

amayama is awesome, and they still sell just the friction discs
https://www.amayama.com/en/genuine-...x/1991_5MT/21668/engine/E__1800?p=9&fromMap=1

Heck, as long as the clutch grabs and the surfaces are ok...I just keep replacing discs. Never had a problem in dozens of cars over decades (I'm old now).