Clutch Options & Suggestions?

[F80_Greg]

Hello everyone,

Anyone have tried and true clutch suggestions for the s55 platform? I know there are only a limited amount of options out there but not much feedback that i could find on how well they perform. I'm getting some really bad slippage at WOT in 3rd-5th gear. Only 30k miles on the chassis with original clutch. This was expected as the car is putting out around 800whp & 700wtq. Anybody out there who has first hand experience with a specific clutch kit that is capable of holding those power ranges, your input would be greatly appreciated. Was hoping to stay away from single mass flywheels since chatter can be really annoying, but looks like there isn't many options. Thanks guys!

[F80_Greg]

Bump!

[F80_Greg]

Bump!!

[Wanted_M]

Good luck with DMF/upgraded PP/clutch holding that kind of power, you need SMF and twin disk. Some sacrifices have to be made lol, a little chatter in return is not that bad for what your asking the clutch to do. Avoid full face as they can't dissipate heat as quickly when launching which can cause them to fuse to flywheel, use a 4-5 or 6 puck sprung hub/ceramic disk which is aggressive but its Johnny on the spot.
Of course this is my experience on other platforms and growing pains/mistakes, good luck.

[F80_Greg]

Originally Posted by Wanted_M

Good luck with DMF/upgraded PP/clutch holding that kind of power, you need SMF and twin disk. Some sacrifices have to be made lol, a little chatter in return is not that bad for what your asking the clutch to do. Avoid full face as they can't dissipate heat as quickly when launching which can cause them to fuse to flywheel, use a 4-5 or 6 puck sprung hub/ceramic disk which is aggressive but its Johnny on the spot.
Of course this is my experience on other platforms and growing pains/mistakes, good luck.

Thank you for your input. I've heard a 6 puck vs a full face is a world of a difference for a car that's almost daily driven. I won't be dumping the clutch at all, just don't want it to slip at WOT.

[Wanted_M]

Originally Posted by F80_Greg

Thank you for your input. I've heard a 6 puck vs a full face is a world of a difference for a car that's almost daily driven. I don't be dumping the clutch at all, just don't want it to slip at WOT.

Yes you are correct, a full face is more forgiving on your leg/tranny/daily drive.
Engagement is less aggressive and better for the street, a 6 puck is grabby as hell, it will shudder like crazy on take off but don't give up. Once broken in I tell ya, it almost gives you the feeling of a DCT as it grabs hard and can handle the kitchen sink lol.
I say SMF/stage 3 clutch but all up to you for the TQ you want and you will have some chatter.

[F80_Greg]

Originally Posted by Wanted_M

Yes you are correct, a full face is more forgiving on your leg/tranny/daily drive.
Engagement is less aggressive and better for the street, a 6 puck is grabby as hell, it will shudder like crazy on take off but don't give up. Once broken in I tell ya, it almost gives you the feeling of a DCT as it grabs hard and can handle the kitchen sink lol.
I say SMF/stage 3 clutch but all up to you for the TQ you want and you will have some chatter.

Sounds good thanks, do you know if a certain brand or model that people are using? I hear good and bad things about all brands out there

[Wanted_M]

Man that's a tuff questions as its a crap shoot, I've used SPEC 3+ to Tilton twins and all have some issues and compromises. One example was my SPEC 3+ full face with SMF I had, bent the fingers on PP after 2 launches with 3500 miles on it. TOB wasn't engaging properly passed 5k rpm as I couldn't shift gears, below 5k all good. Replaced clutch slave then clutch master to no avail, dropped tranny, removed PP bam there it was like a porcupine. Onto the next clutch lol.
I say call and chat with the folks at EAS and/or SSR for their input and go from there.

[RSXDC5]

Spec twin disc here, in 'P Spec' pulling spec, makes for better slipping of the clutch around town. Will hold 1,100wtq and pretty darn drive-able...I used to daily drive it before Covid and working from home started. 1 downside, it's slow to enter the gate of the gear in lower gears, this dissipates in higher gears

[F80_Greg]

Originally Posted by RSXDC5

Spec twin disc here, in 'P Spec' pulling spec, makes for better slipping of the clutch around town. Will hold 1,100wtq and pretty darn drive-able...I used to daily drive it before Covid and working from home started. 1 downside, it's slow to enter the gate of the gear in lower gears, this dissipates in higher gears

Do you still recommend this clutch?

[RSXDC5]

The clutch works great, may be our best off-the-shelf option to be honest. Do I recommend the clutch? Yes, but with a few caveats/drawbacks:
Low rpm cabin vibration on the highway at a specific rpm
Slow to enter gear 1
Slow to enter gear 2
Semi-slow to enter gear 3

Upsides:
Fantastic clutch engagement (I recommend the 'p-spec' or 'pulling spec' vs the default 'st-spec' or 'street/sport spec)
Very very low chatter when slipping clutch
Holds 1,100wtq in 'p-spec'

Misc thoughts:
Clutch pedal is definitely firmer & shorter
If you ever need to change wear items, it's a low cost

[F80_Greg]

Originally Posted by RSXDC5

The clutch works great, may be our best off-the-shelf option to be honest. Do I recommend the clutch? Yes, but with a few caveats/drawbacks:
Low rpm cabin vibration on the highway at a specific rpm
Slow to enter gear 1
Slow to enter gear 2
Semi-slow to enter gear 3

Upsides:
Fantastic clutch engagement (I recommend the 'p-spec' or 'pulling spec' vs the default 'st-spec' or 'street/sport spec)
Very very low chatter when slipping clutch
Holds 1,100wtq in 'p-spec'

Misc thoughts:
Clutch pedal is definitely firmer & shorter
If you ever need to change wear items, it's a low cost

Appreciate the write up man!

[MJ6]

For what it's worth, I initially went with a Clutch Masters FX1000 set up and am switching back to the stock DMFW and Clutch Masters FX250.

Similar to what RSXDC5 stated, these twin disk clutches can definitely hold up to abuse, but there are trade offs that you need to consider. From my experience with the FX1000, the cabin vibration is what did it for me: while technically tolerable, I'm getting old and this is my daily driver.

The biggest difference between the SPEC and CM setups though is the FW: SPEC's single mass comes in at (I believe) 42lbs while CM's is around 17lbs. Less mass equals less dampening ability and more propensity for drivetrain noise. If noise isn't an issue, I think both are excellent options.

[F80_Greg]

Originally Posted by MJ6

For what it's worth, I initially went with a Clutch Masters FX1000 set up and am switching back to the stock DMFW and Clutch Masters FX250.

Similar to what RSXDC5 stated, these twin disk clutches can definitely hold up to abuse, but there are trade offs that you need to consider. From my experience with the FX1000, the cabin vibration is what did it for me: while technically tolerable, I'm getting old and this is my daily driver.

The biggest difference between the SPEC and CM setups though is the FW: SPEC's single mass comes in at (I believe) 42lbs while CM's is around 17lbs. Less mass equals less dampening ability and more propensity for drivetrain noise. If noise isn't an issue, I think both are excellent options.

Thank you for your input! I definitely consider drivetrain and cabin noise as a factor. The car is loud as it is and would like to avoid more noise if possible. Interesting to know that clutch is compatible with the stock dual mass. Did you order a new FW or going to reuse the stock one you had?

[MJ6]

Originally Posted by F80_Greg

Thank you for your input! I definitely consider drivetrain and cabin noise as a factor. The car is loud as it is and would like to avoid more noise if possible. Interesting to know that clutch is compatible with the stock dual mass. Did you order a new FW or going to reuse the stock one you had?

I'll be reusing the stock FW myself as I had it changed out at 21k miles and my BMW mechanic informed me that it still looked good.

It should be going in next week for the swap, so I'll let you know once I have some miles on it how it compares to the twin disk in drivability and cabin noise man.

[RSXDC5]

Originally Posted by MJ6

I'll be reusing the stock FW myself as I had it changed out at 21k miles and my BMW mechanic informed me that it still looked good.

It should be going in next week for the swap, so I'll let you know once I have some miles on it how it compares to the twin disk in drivability and cabin noise man.

^^ This is a really cool setup. Please let us know what it's like when you get it installed!

What wtq is it rated at?

[MJ6]

Originally Posted by RSXDC5

^^ This is a really cool setup. Please let us know what it's like when you get it installed!

What wtq is it rated at?

Clutch Masters unfortunately doesn't provide specific wtq figures, they base it more on a percentage of holding capacity.

Based off of their estimate of 110% increased holding capacity, if we use stock torque ratings of 406ft lbs at the crank and an appropriate drivetrain loss of 18%, it should theoretically hold around 700wtq. For a single disk I think that's decently generous as I'd be happy in the 650wtq range.

[MJ6]

Just an update as I picked up my car from the shop yesterday.

First impressions are good: the loud drone I was experiencing has disappeared and engagement is smooth as butter. My only issue right now is that I'm on a tank of E85, so I have to really watch my pedal input as if I'm not careful the torque hit will slip the clutch as it's not bedded in yet. I'll have to wait until it's fully broken in to give a better review as to its holding capacity.

As a side bar, I do have the Ultimate Clutch Pedal installed and needed to readjust the settings to accommodate the different clutch plate, and in doing so I found that the clutch master cylinder is leaking. Likely my fault as during the install the plunger popped out, but I'll be replacing it next weekend when I bleed the brake system with new fluid.