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I’m looking for feedback from owners of higher output BP engined mx5s. What clutch are you using and successfully with what torque rating?

My target is 400hp/300kw/400ft.lb.

Is there that much secret sauce involved that a local manufacturer could not assemble something adequate?

I have never used a twin plate clutch or dríven a car with lightened flywheel etc, so I have no preference other than not wanting something that will be terrible to put on a trailer or putt around the pits.

I have been going to direct clutch services in albion (or around there) for a while, and use a cushioned button clutch, which was recommended to me a friend with a turbo mx5 as he uses the same clutch. I would definitely recommend giving them a call and they can run you through the options.

I would also recommend a light weight flywheel - they're awesome. May not make as much difference with boost as it does NA

Jim berry single plate in mine prob around 300kw at the engine 1.8 turbo
takes 3rd gear from a dead start 5000 plus rpm clutch dumps no worries tyres go up in smoke
dosnt slip 4 th 5th and 6th at full throttle
Most single plate clutches at that power level tho will be a bit of a pain to drive tho for street duties

NPC cushion button clutch. About $700 holds 300hp for 4 years now and I certainly don’t baby it.
You need to keep the revs up when reversing to avoid a small amount of shutter but other than than that feels exactly like a stick clutch,

plohl wrote:I have been going to direct clutch services in albion (or around there) for a while, and use a cushioned button clutch, which was recommended to me a friend with a turbo mx5 as he uses the same clutch. I would definitely recommend giving them a call and they can run you through the options.

I would also recommend a light weight flywheel - they're awesome. May not make as much difference with boost as it does NA

Direct Clutch have a 300hp option in a single plate, but for 400hp, they recommend a twin plate which is nearly $2k

bear2230 wrote:NPC cushion button clutch. About $700 holds 300hp for 4 years now and I certainly don’t baby it.
You need to keep the revs up when reversing to avoid a small amount of shutter but other than than that feels exactly like a stick clutch,

Thanks Richard,

I’ve sent them an enquiry

mx589 wrote:Jim berry single plate in mine prob around 300kw at the engine 1.8 turbo
takes 3rd gear from a dead start 5000 plus rpm clutch dumps no worries tyres go up in smoke
dosnt slip 4 th 5th and 6th at full throttle
Most single plate clutches at that power level tho will be a bit of a pain to drive tho for street duties

I have acquired a second hand Jim Berry clutch, but it requires a modification to the gearbox clutch pivot point, which I am weighing up - the gearbox the car will be tuned with is not the gearbox that will end up in the car permanently, and I don’t want to modify a good saleable 6speed...

The american was it from jim that said you had to mod it ?
What did he say to do ?
Been a fair while i had mine for think i had to mod the pivot point itself

mx589 wrote:The american was it from jim that said you had to mod it ?
What did he say to do ?
Been a fair while i had mine for think i had to mod the pivot point itself

The clutch and flywheel stack is exactly 10mm taller than stock. To account for this, the pivot point needs to move 10mm to the rear. This is easy to do as the casting the pivot bolt screws into has loads of thread and can be trimmed and still receive the stock pivot pin/bolt.

The clutch fork ratio is about 1.8 so 10mm inside the bell housing becomes 18mm outside it. The clutch pedal ratio is 5.5 an so 18mm becomes 99mm of clutch pedal adjustment to account for the 10mm inside the bell housing.

I have located a source for a pivot bolt that is 4mm shorter, which translates to a 10mm change outside the bell housing, but I haven’t worked out if that is still too long to be manageable within the stock pedal adjustment...

Yeah rings a bell now.
All i remember is when i spoke to him on phone he can talk your ear off hehehe

So, the options so far are all twin plate:

OsGiken TS2B (Don’t know what friction material is used)
Super Miata twin disk (Carbon Kevlar or ceramic)
Direct Clutch twin disk (ceramic)

I've got the Super Miata Twin plate, which is really just a competition clutch setup... there is a dealer in Australia.

It is awesome.

But I'm still sitting below 200hp, so I would just have the lower torque option in plates.

I've also used Direct clutch before for the FD and they are really good to deal with. I wish they could have made something similar to the Super Miata one to stay local, but it wasn't possible.

Tim_cyc03 wrote:I've got the Super Miata Twin plate, which is really just a competition clutch setup... there is a dealer in Australia. .

Thanks Tim that’s handy info. I gave them a call today.

I found a 7.25" twin plate racing setup that Xtreme do too - Xtreme KMZ18523-2E

I would imagine if you could get the flywheel you could mate any 7.25 racing clutch up to it.
Found prices ranging from $1500 - $2200 online, so not cheap.
I haven't used one so can't give an opinion on it.

CrazyRacer wrote:I found a 7.25" twin plate racing setup that Xtreme do too - Xtreme KMZ18523-2E

I would imagine if you could get the flywheel you could mate any 7.25 racing clutch up to it.
Found prices ranging from $1500 - $2200 online, so not cheap.
I haven't used one so can't give an opinion on it.

Wish there was a like button. Thanks for sharing CrazyRacer