Do i need a heavy duty clutch??

**ctrain** · 03-10-2013, 06:59 PM

So ive just installed my 3tc turbo with a t50 5 speed, the motor was built using a heavy duty clutch but it wouldnt work with the t50, so i put a new standard one and i it worked, but whenever i give it a bit the boost kicks in for a second then it just revs out and has no power in all gears, ive rebuilt the gearbox so it cant be that, is the clutch not putting enough clamping pressure when the boost kicks in?

Cheers,
Callum

**dnegative** · 03-10-2013, 07:08 PM

Revs out?
Does it flair or does it run like a NA and rev out all the way steadily?

If it flairs either your spinning the wheels or the clutch disk, you can normally smell it when the clutch is slipping.

**ctrain** · 03-10-2013, 10:16 PM

nah its not getting any wheelspin, it sounds like the turbos kicking in and the revs climb high quickly, like a normal turbo engine. i might get a video of it tomorrow and see if that show the problem better

**brucey** · 03-10-2013, 10:53 PM

What brand heavy duty clutch did you have? How come it didn't work with the T50?

When it revs out with the boost can you gain control when you ease off the accelerator?

**lexsmaz** · 03-10-2013, 11:13 PM

Certainly sounds like clutch slip, does it smell too ...

When the revs rise it sounds like the speed is not rising at the same rate, As an example if you are driving in say 3rd gear at 2500rpm at 70 kph & give it a bit so it starts to slip, if the revs rise to say 4000rpm you should be doing 112kmh & if you are not doing that speed then the clutch is slipping ..

Or as has been said, watch the speedo as the revs rise & if you back off & the revs drop & the speedo doesn't change its just clutch slip ..

Pretty easy diagnosis ..

**dnegative** · 04-10-2013, 08:48 PM

Originally Posted by lexsmaz

Pretty easy diagnosis ..

Basic clutch test 101
Give it some revs and drop the clutch, if it skids or hooks up without issue then the clutch is working.
If skids are not you thing, find a good hill, go up in a tall-ish gear and just when it starts to load up good give the clutch a quick boot and watch the tacho. If it drops back to where it should be straight away its sweet, if it takes its sweet time or doesnt, she is fucked.

**allencr** · 04-10-2013, 10:52 PM

Do i need a heavy duty clutch??
NO, not yet as there's no evidence of it being inadequate & too small for the job, only that it's slipping immediately after being installed & doing it under low power.

Is this disk thinner then the one that you originally got with that pressure plate?
Does the clutch fork move freely, not putting any pre-load on the clutch & not letting it engage completely?
Any oil dripping from the bellhousing?

**ctrain** · 04-10-2013, 11:48 PM

Its an exedy clutch, i drove it today but didnt flog it, im going for another good drive tomorrow so ill see if it smells, the clutch does grab as theres been a few times where its spun the wheels.

It didnt work with the t50 because i couldnt find a thrust bearing carrier that would work with the old heavy duty clutch as the forks were to fat and the bearing was to big so it made it impossible to engage, i have adjusted the fork so its about 10mm off the plate and it has a strong return spring so its not pushing on the plate.

**brucey** · 05-10-2013, 10:26 PM

The clutch behind my 3TC slips a bit and that's NA. I'm installing a new heavy duty clutch at the moment (rpm clutch industries). When I took the old clutch out I noticed it was the smaller 2TC clutch (190mm) instead of 200mm. Also the rear main seal was leaking. That might of leaked oil onto the clutch. Haven't got to the thrust bearing yet.

**o_man_ra23** · 07-10-2013, 09:47 AM

What is your flywheel like? If the clutch has been slipping the flywheel surface will develop heat spots and stress fractures pretty quickly. Also it will affect the effectiveness of the organic material on the plate. Putting a turbo on a normally NA motor is always a good reason to upgrade the clutch.

**ctrain** · 07-10-2013, 10:18 PM

the flywheel was never machined but it still had a fair bit of meat on it left, i asked the guys at the local clutch joint and they said it didnt need to be machined, i probably will get a heavy duty clutch in the next few weeks.

Cheers,
Callum

**brucey** · 08-10-2013, 10:22 PM

When I changed my clutch I took the flywheel off to get it lightened. Had the weight reduced to just under 6 Kg. Was 11 Kg originally. Cost $230 for lightening, balancing, and machining the face. Also included balancing the clutch pressure plate while it was on the flywheel. They had to weld a piece of metal to the pressure plate to balance it.

**ctrain** · 11-10-2013, 06:05 PM

i think i may have found the problem, im going to hook up a boost gauge tomorrow and see if the wastegate is sticking open causing the loss of power, hopefully its that so i have an excuse to pull the engine out again

**ctrain** · 12-10-2013, 05:22 PM

hooked up the boost gauge and im getting 7psi on boost, and when it revs out, it seems that if i go easy on the throttle it boosts but if i plant it it just revs but has no power, yet the boost gauge still shows 7psi, not sure if its a downside to a suck-through turbo setup, or the clutch cant handle the sudden power, either way im putting in a heavy duty clutch, thanks guys for all the replies!

Cheers,
Callum