Race Engine Forum UK

Just something I've been considering lately.

I had the whole rotating assembly balanced as part of my engine build, however, I'm considering changing the clutch. Its very aggressive and I might be doing more road driving that I had initially spec'd for, being that its a race clutch. A few options I've been looking at are:

1. Just put up with the aggressive nature of the clutch.
2. See if I can get less aggressive friction plates.
3. Swap the entire clutch/flywheel assembly out.

What would you do in this situation??

Thanks,
Ant

Need to know the type of clutch,

G

The one that I'm considering taking out is the one that I sent up to you Guy, and you checked it all out for me.

The clutch came with flywheel and all other fittings needed, so I would need to change out the flywheel and clutch if I go this route at a minimum. Its a great clutch for what its meant for, but I don't think I'll be as dedicated to drag racing as I once thought I might be.

I might just be having bad memories of it though, after all, its been 51 weeks since I drove the car, so thought I'd ask the question while it was on my mind.

OK, sure, this one.

Unless you can get a sprung paddle clutch of the requisite torque capacity - in which case FW will need complete machining and whole crank,fw, clutch assy re-balanced (and anyway paddle clutch are also pretty harsh) you're stuck with it.

GC

Yes Guy... thats the one alright.

Do you think that getting some less "grabby" friction plates would be the most feasible way around it?

Ant

You won't get any, all single/twin/triple plate 7.25 (and smaller) are like that,

GC

Oh right. I thought it was the friction meterial (ceremetallic) that dictated the verocity of the bite?

Yes, but all single/multiplate clutches like that all use sintered or cerametallic facings and the have more-or-less identical frictional (and, importantly - wear) characteristics. Indeed paddle clutches do too.

Given that the facings have the same frictional (mu) value the capacity depends principally on the clamp load from the cover and the frictional diameter. These type facings are very hard and 'snatchy', and so they don't slip much compared with the organic facings used on conventional style clutches. Indeed if you slip them they burn out quite quickly, they are a 'drop and go' race design. Moreover your clutch has no torsion springs to absorb the shock load as the system engages.

My view is that you may have to go with it and get used to it. The GpB Ford Escort RS200 with Hart 16v turbo mounted in the back ran a triple plate so you're in good company.


GC

Thanks Guy. That definately cleared up a lot of the differences between the clutch types.

thank you,
Ant

If you want a Tilton that will allow for some slip you buy a carbon/carbon clutch. They are very good at what they do, just outside most folks' budget.
Other than that, its like Guy said!

So carbon is more "slipable" than the ceramettalic plates?

Just had a look at Tiltons site, and it doesn't look like they do them for the 7.5" rally clutch.

Ant,

all clutches burn & thus lose material if you slip them deliberately, the thinner the friction layer the shorter the life....

G

surely there would be a difference in wear rates though?

I'm pretty sure I've exhausted all options of changing components on the specific clutch I have fitted. As such, if I want to change clutch I'll have to do flywheel as well, and also get a new bell housing and slave cylinder too.

Best I get used to this one me thinks!