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MG MGB Technical - Performance clutch disc

I was just browsing the Moss site picking out the bits I'll need to get my over drive tranny in when I noticed they sell a performance clutch disc. I did the clutch on my car not too long ago so I was going to just swap in a new friction disc and throw out bearing. Is there any advantage to running the performance/race disc vs. a stock disc if I will be using the standard borg and beck pressure plate?

I don't drag race this car or anything but I certainly put my foot in it a fair amount and wouldn't mind a little extra grabbing power.

thanks

-Bill
Bill Mertz

This disc is probably the TR7 disc, a little larger in diameter than the MGB but still fits under the B pressure plate. A little more area. No relation to a competition clutch.
DENIS4

When I last looked at this a few years back the recieved wisdom had gone back to the OE setup. I was only changing it while the gearbox was out and the previous OE fit was OK, and the new one has been fine. So if you go for it let us know how it works :-)
Stan Best

You won't see any improvement with the disc.

I run a stock disc (but HD cover) in the race car.
Bill Spohn

Bill,
That was gonna be my other question, does updating the pressure plate with a stock disc do anything. My only concern with the stronger cover is prematurely wearing out the slave cylinder.

I think I'm gonna go stock for now, maybe when I get around to putting the ported head back on I might upgrade, we'll see.
Bill Mertz

The stronger pressure plate won't hurt the slave cylinder but will wear out the clutch release bearing much faster. Stock is a good choice.
J Heisenfeldt

Bill,

If you recntly changed your clutch I would not bother renewing any of the parts unless they show signs of wear. Provided you never ride the clutch and the hydraulics are in good condition the stock parts should last many 10's of thousands of miles. However, if the hydraulics are poor, or if you rest your foot on the clutch while driving (even lightly) then the bearing can wear rapidly. Last time I had an engine out I had a new clutch on hand, but I didn't need it and returned it to the supplier.

Cheers
Iain
67 BGT
I D Cameron

If you have a high output engine, you can slip the clutch at higher RPM under full acceleration.

Not an issue with a street engine and a clutch in good shape.

Most of the wear comes from slipping the clutch which is generally from bad driving practice. If you don't do standing starts in racing the clutch will last very well.

One service item that is important is ovalled eyes in the pushrod. You can fix that with weld and redrill.

You ought to see the special clutch I use in the turbo Fiero - the disc is lined with ceramic discs so it can take sharp starts with 300 BHP.
Bill Spohn

I've used the TR7 disk now for about 40k miles now. I don't know exactly what it does over the standard but it still works fine! Glenn Towery pointed me on to it. Perhaps he'll chime in.

Paul
Paul Hanley

I've run TR discs for years in my Bs. They work great are last a bit longer.
Steve Simmons

The TR7 disc just has a wee bit more friction area and uses the same hub so it fits the spline of the MG input shaft.

I seem to recollect that we used to use a Lotus clutch on the MGAs for the same reason. The slight added area probably doesn't really buy you much, but given the choice, why not opt for what might theoretically last a tad longer.

Bill Spohn

This thread was discussed between 05/08/2008 and 07/08/2008

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