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Duratec Clutch slip
ChrisJ15 - 29/7/18 at 08:11 AM

Ive got a Duratec from an ST150 in my J15. When I do a quick gear change and rev match the clutch spins up. If I change and take my foot off the throttle and only accelerate once the clutch is fully out it's fine.
Also when the clutch is out and I stand on the throttle theirs no slip.
Does this meant eh 200bhp from the Durratec is simply too much for the bog standard clutch or does it mean the clutch is beggining to go?

snapper - 29/7/18 at 10:44 AM

Without feeling the clutch action difficult to tell
Could be the hydraulic release bearing being a bit to close i.e. not fully engaging the clutch once released or I have seen a situation on a Corsa VXR that only slipped on overboost, when taken apart the clutch had slight witness marks on 3 rivets.
Doesn’t take much to unsettle a clutch

ChrisJ15 - 29/7/18 at 11:06 AM

The donor car only had 8K on it which wouldnt be much for a clutch.
All hyrdaulics away from the clutch are new. I wonder if there's anything on the hydraulic side that could cause it?

rusty nuts - 29/7/18 at 11:34 AM

Do you have any type of clutch pedal stop fitted ? It could be a possible cause? I've known clutches to wear out in a lot less than 8,000 miles ,it really depends on how it's been driven more than mileage.

ChrisJ15 - 29/7/18 at 12:05 PM

Ive got a clutch stop but it was only roughly adjusted but its only done 500 miles since IVA.

rusty nuts - 29/7/18 at 01:08 PM

Make sure you have a small amount of free play at the pedal before the movement starts to push the M/C pushrod . It may be possible to adjust the pushrod length if needed.

adithorp - 29/7/18 at 02:20 PM

quote:
Originally posted by ChrisJ15
...do a quick gear change and rev match the clutch spins up. If I change and take my foot off the throttle and only accelerate once the clutch is fully out ...


Care to explain that more as it reads like on your "quick change" your accelerating while the clutch isn't fully engaged. In other words, you're deliberately slipping the clutch on upshifts? If that's the case then I wouldn't expect the clutch to last long.

Rev matching is something I'd associate usually with down shifts and then by blipping the throttle while double declutching.

ChrisJ15 - 30/7/18 at 07:00 AM

I mean not fully coming off the throttle so the revs dont fall away. Not hard on the throttle but trying to keep the revs where they will be when the next gear is engaged.

Andy S - 30/7/18 at 12:56 PM

What size line is your clutch line 3/16 or 1/4?

ChrisJ15 - 30/7/18 at 03:37 PM

Its the same as the brakes 3/16th.

Andy S - 30/7/18 at 10:10 PM

quote:
Originally posted by ChrisJ15
Its the same as the brakes 3/16th.


Every rear/mid engine car I have had uses 1/4 for the clutch as there can be too much resistance to fluid flow with the long run of 3/16 - Maybe that 3/16 would be borderline okay but one of the flares in the run has resulted in a restriction. You pushing the fluid one way is fine but when the clutch pushes it back it takes that fraction of a second longer.

ChrisJ15 - 31/7/18 at 05:10 PM

Just checked the build 'manual' (half finished word doc) and it does actually say 1/4" pipe for the clutch - cant believe I missed that!
The thought of putting a new pipe through the tunnel is pretty horrific tbh.
I do have a spare 5/16th pipe as the build manual said put two fuel lines through but the Duratec configuration only needed one as the regulator was at the front.
Could I use 5/16th?

Andy S - 31/7/18 at 07:58 PM

quote:
Originally posted by ChrisJ15
Just checked the build 'manual' (half finished word doc) and it does actually say 1/4" pipe for the clutch - cant believe I missed that!
The thought of putting a new pipe through the tunnel is pretty horrific tbh.
I do have a spare 5/16th pipe as the build manual said put two fuel lines through but the Duratec configuration only needed one as the regulator was at the front.
Could I use 5/16th?



I suspect that the 5/16 would be a PITA to bleed you could use braided line if it made it easier to work it through and fix it.

ChrisJ15 - 1/8/18 at 03:47 PM

TBH I'll probably give it a go as it's quite easy to get some fittings for either end.
I've got a decent vacuum bleeder and it will take a faction of the time compared with running even a flexible line through the tunnel. Nothing major lost if it wont bleed.
I'll just drive it a bit more sympathetically for the time being and sort it as a winter project.
At least I know my clutch isnt on the way out!

Thanks for all the advice guys, much appreciated.