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The mkiv Supra Owners Club

Has my clutch gone, or is going?


Jake

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Ever since TOTB last year I've had a problem with my clutch slipping (bloody drag radials give too much grip)

 

...but to me it doesn't seem like classic slipping clutch symptoms. It starts slipping from around 4500 if I WOT rev the car in 2nd or 3rd gear, then when I go for the next gear it slips again straight away. But if I back off the throttle for sec then give it WOT in the higher gears it doesn't slip.

Isn't that arse-about-face? Doesn't a slipping clutch normally slip worse in the higher gears, rather than the lower ones?

 

It's an OSGiken clutch. Twin plate I think (not 100% sure really) and I believe it's a 'push' type.

 

I've just lived with this problem for the last 10 months and it didn't get any worse in that time, but now I've fitted a larger turbo it's slipping more - so I guess I better sort it out.

 

 

So, should I just get the clutch plate changed? Or do the symptoms suggest something else could be the problem?

 

 

Any thoughts?

 

Thanks

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I'd expect more torsional stresses on the lower gears,

 

Mine went exactly the same way,could barely get grip until 3rd or 4th

 

Got the rps street 6puk, highly recommend it, lighter than stock, doesnt make the rattle(Cyn-r-g lightweight Flywheel) and when I go single I'll upgrade to the max street combo (Bigger pressure plate)

 

Out of interest how long did your upgraded clutch last? Your car is single isnt it?

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Unfort the Os Giken Clutches aren't design for slipping and hard launches... the amount of heat that will be generated whilst launching will simply destroy them...

 

I have allot of friends that drag race.. and people with these clutches suffer the same problem... IF your going to drag race why not get a clutch designed for it.. .OS Giken are only really a high power/Torque clutch designed for not slipping and for the street.

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Unfort the Os Giken Clutches aren't design for slipping and hard launches... the amount of heat that will be generated whilst launching will simply destroy them...

 

I have allot of friends that drag race.. and people with these clutches suffer the same problem... IF your going to drag race why not get a clutch designed for it.. .OS Giken are only really a high power/Torque clutch designed for not slipping and for the street.

 

That's where the OS Triple plate come in handy. ;)

 

Jake you can get replacement plates, PM me for info:)

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OS Giken are ceramettalic lined clutches and are not suitable for drag racing, they are a circuit race clutch, or a fast road clutch. They need periodic adjustment by someone that knows what they are doing. 90% of the ones I see that are prematurely worn out have either been regularly used for drag starts, haven't been adjusted at all, or adjusted incorrectly (have a triple plate here now like that), or used by someone that really ought to consider an automatic as their next car.

 

I supply most repair kits same day, and regularly get full clutches in. I have all the correct OS Giken installation tools, too.

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That's where the OS Triple plate come in handy. ;)

 

Jake you can get replacement plates, PM me for info:)

 

At the end of the day... you need to get something design for its specific purpose..

 

the more you abuse it the less life it will have...

 

Its the same theory with engines...:)

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OS Giken are ceramettalic lined clutches and are not suitable for drag racing, they are a circuit race clutch, or a fast road clutch. They need periodic adjustment by someone that knows what they are doing. 90% of the ones I see that are prematurely worn out have either been regularly used for drag starts, haven't been adjusted at all, or adjusted incorrectly (have a triple plate here now like that), or used by someone that really ought to consider an automatic as their next car.

 

I supply most repair kits same day, and regularly get full clutches in. I have all the correct OS Giken installation tools, too.

Interesting.

Would it be worth having my clutch adjusted to see if that fixes the problem? Or is it unlikely to?

 

How does one adjust these clutches? Is it a 'box off' job?

 

If I need a new clutch; Would it be a lot of work to convert it back to a stock pull-type clutch with a stock flywheel?

What would be a good choice of fast road clutch that can cope with 500-550rwhp? I'm not interested in spending £1000+ on a clutch though.

 

Thanks

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Interesting.

Would it be worth having my clutch adjusted to see if that fixes the problem? Or is it unlikely to?

 

How does one adjust these clutches? Is it a 'box off' job?

 

If I need a new clutch; Would it be a lot of work to convert it back to a stock pull-type clutch with a stock flywheel?

What would be a good choice of fast road clutch that can cope with 500-550rwhp? I'm not interested in spending £1000+ on a clutch though.

 

Thanks

 

You adjust the throwout bearing pushrod first, then the master cylinder pushrod. Box in situ, just be sure to have some throwout bearing clearance on the cover fingers.

 

I keep all the (hard to get and quite large inventory) parts to convert from push back to pull in stock. My uprated clutch would cope with this *IF* you didn't animal the clutch or get tempted to go to the `Pod :) See below:

 

Available now: Uprated MKIV TT clutches.

 

An uprated clutch assembly.

I use a stock, brand new, genuine Toyota driven plate, as it is correctly

balanced, doesn't judder and will hold all but mega torque

highly modded engines or cars used for drag racing.

I modify a stock brand new genuine Toyota cover to give more clamping force.

The reason I tooled up to do these is some of the aftermarket

US clutches I have fitted SEEM to be built from used cover

assemblies with reground friction surfaces, and a stronger

spring. I have had hellish trouble getting these to fully

release, because due to this seemingly thinner cast iron

friction face, the geometry of the clutch goes to pot, and

being a pull type clutch (the hydraulics pull the bearing

away from the engine, rather than the more normal push type)

it is a lot harder to effect a cure.

 

For 475 pounds, no VAT to pay, you get a brand new driven

plate, a brand new modded cover, and a brand new release

bearing. I would rather fit myself so any complaints are down

to me, I see too many clutches juddering due to someone without

the right gear allowing the gearbox input shaft to bend the driven

plate. The gearboxes weight is allowed to swing on the plate centre,

bending the centre, or clutches fitted to patently buggered flywheels.

 

However, I might be persuaded to sell to people using bona fide fitters to install one.

Toyota use a dual mass flywheel (the flywheel is in 2 parts, an inner and

outer assembly, damped in the middle) which is now showing signs

of wear causing a lot of rattle when idling or on very light

throttle openings. For God knows what reason they are charging

about 270 quid for a new one, they look more like they should be

over 500 to me, but don't say anything :-) So if the flywheels

old enough or abused enough to be scored it's best replaced.

If pressed I will sell the clutch kit, which includes a new release

bearing for a 3rd party to fit.

 

Fitting by myself will cost £175.

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RPS is deffinantly the best way to go for the money! I have had the Carbon Carbon in my car with the lightened flywheel for about 25,000 miles and it has held that 1000hp strong, for any application. They also rebuild the clutch if you have any issues with it. Unfortunantly they do not sell a rebuild kit.

 

Cheers,

 

Joe

 

I'd expect more torsional stresses on the lower gears,

 

Mine went exactly the same way,could barely get grip until 3rd or 4th

 

Got the rps street 6puk, highly recommend it, lighter than stock, doesnt make the rattle(Cyn-r-g lightweight Flywheel) and when I go single I'll upgrade to the max street combo (Bigger pressure plate)

 

Out of interest how long did your upgraded clutch last? Your car is single isnt it?

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Guest WJX808
RPS is deffinantly the best way to go for the money! I have had the Carbon Carbon in my car with the lightened flywheel for about 25,000 miles and it has held that 1000hp strong, for any application. They also rebuild the clutch if you have any issues with it. Unfortunantly they do not sell a rebuild kit.

 

Cheers,

 

Joe

 

Better change it to Auto trans. even most drag these days use auto...auto rules!!!

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