... Slip a new clutch on a A12?

Today while road testing going up a steep hill on 18 pounds the revs built and the car didn't move - guess the clutch started to slip! This really bummed me because I dont abuse clutches (unless 18psi counts lol) - I dont do burnouts or launch the car and today even though it pulls mega hard the accel. felt a bit flat and up a hill it was obvious the clutch is slipping!

So does anyone know of a good replacement? Any specific brand names come to mind other than exedy?

Although I turboed my engine myself (built the manifolds/pipes/exhaust/connected it all up and tuned it) im actually clueless about the clutch!

Does anyone have any idea how I'd go about it with leaving the engine in. I do have a HD floor jack on wheels and jack stands if that helps - I can buy some car ramps if needed too?!

I was looking at rebuild the gearbox (4spd) or finding a 5 speed too - I guess this is a good time for it?

Some pointers would be awesome!

I have a brass button clutch and I can't remember where it came from.....it still slips when I really drop it but I guess the pressure plate might be nearing expiry!

Anyhow you should be fine doing the clutch with the motor still in but the alignment can sometimes be a pain in the ass. Once you disconnect and remove the tailshaft (drain gb first) and the engine is resting only on the mounts (exhaust disconnected too) it will tend to rock backward giving a decent angle to get the box up and back in place.

Ah thats good news then so I think I'll need car ramps then.

Also a quick look on the exedy site and my options are OEM replacement (not gonna happen), full face HD organic (I dont hink it will hold up), "Cushioned button" or regular Button.

So if I go the exedy route then I have to decide between their regular button or the cushioned button (which looks like a cross between full face organic and just button).

Does anyone know of other performance clutch manufactuers for the A-series?

It's torque that causes the clutch to slip.

At 18psi, you may have 2x the stock torque...too much for an A12 clutch cover which is rated low for easy pedal effort.

* B210 A12: 616 pounds
* B210 A13: 694 pounds
* B210 A14: 794 pounds
* B310 A12A: 573-684 pounds
* B310 14/A15: 739-849 pounds

Yeah good point. So Ive worked out that the excedy button clutch is for drift/drag/rally/circuit and the HD organic is just a street car clutch - basically.

It sounds like that the Execdy Sports Tuff Ceramic button clutch is the ticket - now to find a price!

NSK-6121HDB is the part number if anyone is interested.

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After a quick look it seems around $500 is the price - oh dear I better start saving lol. Does this price sound about right?

that price sounds pretty good for a button clutch

button clutch has little to do with driving along and the clutch slipping. Those racing clutches are designed for clutch engagement issues.

To prevent slipping while driving, you need a pressure plate (clutch cover) that can hold the torque output of the engine under load.

Nismo part numbers:
* 30210-H5220 420KG (926 lbs) NISMO HIGH-PERFORMANCE PRESSURE PLATE for A12, A12A
* 30210-RS100 Clutch Cover 550 Kgf
* 30210-A1200 550KG (1213 lbs) NISMO HIGH-PERFORMANCE PRESSURE PLATE for A14, A15

30210-RS100 is still available, $200 at PitRoad.

Top it off with a tough street/strip clutch disc
* 30100-RS200 Disc Clutch 180 Ø 20x18T Ceramic Type B [Tri-lobe]$220 at PitRoad.

get a heavy duty A15 vannette pressure plate, they have the highest clamping load of all the A series clutches. and if you actually get the clutch from a clutch specialist you can get them to have it made with an even higher clamping force than any of their off the shelf clutches.
for a heavy duty a15 clutch kit with just an organic clutch plate it should be under $200
then a solid brass button centre would be another $100-150 im pretty sure
if you go a cushioned button clutch the price goes up a bit more, and all its doing is giving your gearbox and diff a little easier time if you change gears hard.
from personal experience it is no harder to drive a car with a button than it is with a cushioned button. ive found that the clamping load of the pressure plate has a lot more to do with it as it tends to throw your foot off the clutch pedal when you are releasing it

i wouldnt go any of their off the shelf kits that are to suit an a12, as they would probably have the same clamping force as a stock a15 clutch

if i were you i'd just get an uprated A15 heavy duty clutch with an organic plate. my brothers corolla was running a similar thing(uprated celica HD organic) behind a turbo 3t and i cant remember it ever slipping until the gearbox front seal leaked and got oil all over it. and that didnt get driven nicely

even the sports tough HD clutch i got for my L series was only $200 and then an extra $100 for a solid brass button centre. and i know A series stuff is cheaper

EDIT, i forget if the A12 ans A15 clutches are the same size as my experience was in getting a clutch for an A15. but even so it would possibly be worth changing to an A15 flywheel so you can run a larger clutch if that is the case

I know clamping force is what stops the slipping; hell, I even considered just shimming the diaphram spring with washers for more preload! - I just assumed the "highest" performance clutch there would have the best clamping force.

So does an A15 clutch fit a late model A12 flywheel and B310 gearbox? If so then a HD A15 clutch is the go and should be cheaper yet.

Also wouldnt a button clutch slip more as there is effectivly less surface area in contact between the pressure plate and flywheel?

I reckon a full face HD organic plate and a decent pressure plate would be the better setup for me (not an all out race car but is does make a fair bit of torque).

the less contact area the better, get a piece of paper and put your hand flat on it, then try and pull it out. do the same thing with just your finger tips pushing down on the paper...should be harder to move
same force being exerted but it is concentrated on a smalller area

anyway, an organic clutch plate should be fine for you though if you have the higher clamping force pressure plate