Why should sintered type clutch plates only be used with grey dot diaphragms?

The clamping force required to stop slipping determines spring type, there are other factors.

If you need a sintered paddle though, you probably need a grey spring. Think of hard brakes such as mintex 1144, you have to press pedal harder don't you.

If you had a 998 with 35 hp, i doubt you'd need a grey spring with the sintered paddle

Daniel

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Videos - Turbocharged A-Series on Dyno & at Wakefield
Mafs waz not my strong subgeckt at skkol

Well the coefficient of friction is way less than a std plate when cold, so it needs more gripping pressure.
Generally the Orange dot is recommended with a race/rally bonded and rivetted plate, the Grey or double Grey diaphragm with the sintered one.
Orange dot might hold it for a moderately tuned motor.

<edit> Grey diaphragms are harder on the crank thrust washers.... not good sitting at lights with clutch in.

No way I'd run the sintered paddle plate on the street, I had one in my Fiat 124 Sport for 1000 miles and couldn't wait to pull it back out.
The extra inertia of the heavy plate killed upshift and downshift times, bad news for baulk ring life too.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

This is my clutch plate.

For all my race engines have never needed anything but the AP bonded & riveted clutch plate and either orange or grey diaphram. Never had a problem with clutch slip or anything else. I run latest GR race cam and head. Steve

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Steve

Ok looks like it's back to the parts shop for me

willy, make sure you set your flywheel/diaphram up properly, have GR do it if in doubt.

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Steve

GR will be doing the motor assembly so I have no doubts that it will be set up properly

I just gotta get most of the bits together so I can send them off earlyish next year

So what is Santa bringing you??? Have you been good thru the year??

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Steve

I have been good.

I have a wedged crank (although it is big J A+) - whole motor is A+
A GR head
RE13
40thou over block
rebuilt gearbox
tran-x 4 pin diff
1.5:1 rockers
45dcoe on GR 5.5" manifold
'S' backing plate lightened
lightened fly

now i am in the stage of wrapping up all the bits to send over...
i am sure GR will want to do some more machining as the assembly begins.

That will be a good unit and you will enjoy. With the power it will make, AP Racing bonded & riveted clutch plate and orange diaphram will be more than enough. You could go to grey now if you planned on upgrading to more power later.

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Steve

I am expecting 110HP @ the fly.
GR reckons very acheivable with my head

willy, goto the turbo mini forum, most of the guys with 200+hp are using grey diaphragm no worries, this is almost double the hp but the torque is the thing to consider most...

Sintered paddle is good once you get used to the 'tight' friction point, if you've ridden a motorbike before you would know what I'm talking about, they are very hard to 'slip'.

Also to consider is the tyre grip, sticky means more clutch pressure req'd.

I built an engine in 96 (1380 with 115hp on GR's dyno) and this had a std clutch facing with a orange spring, this is similar to what justminis suggests. I can't recall if the clutch slipped but it certainly slipped street tyres no probs

Daniel

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Videos - Turbocharged A-Series on Dyno & at Wakefield
Mafs waz not my strong subgeckt at skkol

I'm running a 1360 with around 120+ HP at flywheel, it has Orange dot diaphragm and a B&B standard road plate.
Set up as per Marcel Chichak's method.
Pedal effort is now less than my old S blue dot one was (it was incorrectly set up).
I have no trouble frying A008s to 8000 rpm... no clutch slip!

I `might' fit an AP bonded and rivetted race plate next time, but for street use I've never killed a B&B road one.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I really shouldnt let opportunities like that one go.