Clutch slipping (M90/TTV/850R Clutch) redblock

Hey Guys,

my 3000km old TTV/850R flywheel/clutch started to slip in 4th gear, when i upped the boost to 1.4bar/21psi. Did anyone try one of these or used something else?: https://www.classicswede.co.uk/240m...TVM90_850_SVC70_T5_etc/p1733344_17157484.aspx

Not sure if my m90 will like it haha.

Specs:
- unopened b230fk with 250kilometers
- 530 head with a bit of bowl work, shaved 0.5mm and a Ipd-Cam with new valve springs (stock)
- Ebay T3/T04e China-Trim A/R .50 / A/R .63 at 21psi
- 3" Exhaust - 3" 200cell cat
- 012 maf / 440cc Green Giants injectors
- Stoni´s chips (lh/ezk)
- Kl-Racing Intercooler
- Snowperformence Water/Meth Injection (starts at 6Psi)
- TTV Racing Flywheel with 850R Clutch
- Bosch WR5DC+

Cheers

at least that friction disk has springs in the hub. You need them if you use a solid flywheel. Otherwise it will be very hard to drive in everyday street use.

Why did the old clutch start slipping? 3000km is not a lot at all. What kind of pressure plate is in the old setup?

I have been using an 850R friction plate and a 940TDic pressure plate on a stock deepdish flywheel for many thousands of KM's without issue (tweeked B204GT, 240-ish hp). Maybe you were not using a strong enough pressure plate in the old setup? If that is in fact the case then i don't think that 7-puck friction disk will solve the issue.

Presuming your application is whiteblock? If YES, check Homer's thread..... he upgraded his 850R clutch to the "707" spec unit, I believe. Same clutch is referenced in the famed M90 thread, from Fred......

I have a similar issue with mine. I've got a full 850R clutch kit fitted to a solid TTV flywheel I used to replace the stock dual mass.

Mine slips in 3rd, 4th & 5th if I give it death around 2500rpm. I've had it on a Dyno showing around 450 - 470nm / 340lbft at full boost around then so it's feasible it's actually just slipping if you are making the same as mine is. There is something on the classic swede website about possibly having to shim the pressure plate out so it achieves full travel and full clamping load but I can't verify this will work as I've not tried it personally. I also didn't put the clutch in myself and I remember mate telling me there was issues getting the slave cylinder travel correct. If your clutch pedal is super light it may be it isn't fully engaging.

Hey, have you shimmed the pivot ball?

It's not sure the pressureplate gives the highest clamping force at the thickness of the clutch disc. If you have the possibility, have it measured and probably you will need to shim it.
BR

thanks for the replies guys.

well it's not a mechanical fault. it was holding 400nm (20T Turbo) for 3000km just fine.

The clutchset is capable for 420nm. I guess i'm just making slightly more which cause the slipping.

So my question: what's the best upgrade? or did anyone upgrade to the product in the link.

swizzy said:

thanks for the replies guys.

well it's not a mechanical fault. it was holding 400nm (20T Turbo) for 3000km just fine.

The clutchset is capable for 420nm. I guess i'm just making slightly more which cause the slipping.

So my question: what's the best upgrade? or did anyone upgrade to the product in the link.

Click to expand...

Yep you just reached the limit of the clutch. I ended up going to a sachs 707 pressure plate with the 850R disc. You will have to redrill and repin the flywheel to fit the new pressure plate.
https://www.autodoc.co.uk/sachs-performance/2692983

It sounds like you have reached the limit of the clutch. I have the flywheels ready for the 707 cover that can be used either with the R friction plate or a sprung paddle plate

hey,
https://www.classicswede.co.uk/240m...TVM90_850_SVC70_T5_etc/p1733344_17157484.aspx isn't this a straight fit to my current ttv flywheel?