Clutch for Daily Driven 6spd 650+WHP

[MJ6]

I'm in the final stages of my build and am shooting for DD figures of 650-750WHP and 600-700 ft lbs of torque on Kratos turbos and e85. While I've read that the stock 6spd clutch is generally adequate in most cases, I have concerns about it's ability to hold up under increased torque loads.

While I want to ensure that the clutch is up to the job, I'd also like to maintain drivability as it's my daily. I'm not too keen on SPEC clutches as I've had my fill of them on previous platforms, and while I'm not necessarily a Clutch Masters fan-boi I like the options they have available for the F8x chassis.

The two that caught my attention were the FX250 and FX350, both offerings of which with the rigid hub are compatible with the OEM dual-mass flywheel. Here's my conundrum: while the FX250 is the better choice of the two for daily drivability, I'd be concerned that the clamping force wouldn't be sufficient (not that I'm clutch dumping or driving overly aggressive mind you). The FX350 on the other hand is designed to handle higher torque values, but at the cost of drivability (to what extent though is unknown).

Does anyone have personal experience with either of these clutches that wouldn't mind providing some feedback?

TLDR:
Clutch Masters FX250 or FX350 - clamping ability versus drivability, which one and why or will the stock clutch be enough?

[MJ6]

Just for clarification, I’m not 100% against Spec clutches if there’s one that’s known to work, I’ve simply had bad experiences with the brand on a different vehicle. I do know they offer a twin disk variant called the Super Twin though which I was looking at initially, but so far I haven't been able to find reviews.

I also saw that Clutch Masters has a twin disk offering as well in the FX850 strapped version, but I wonder if that would be over kill for my goals.

Any feedback on any upgraded 6 speed clutch would be welcome as I wade through the available options.

[TacoJova]

I run the FX1000. After talking with them about my power level and how I drive they recommended that. As far as spec I wasn't able to even get on the phone with them so I have no clue

[TacoJova]

Also the FX850 is a super aggressive clutch which isn't for daily duties. I don't daily mine but I drive in traffic and the fx1000 isn't too bad

[m3elmo]

not same but a data point in that I had the fx350 with the lightened flywheel on my e46m3 and it would have been fine as a DD.

the bigger thing to consider is the clutch delay valve. do you want it there still or not.

[MJ6]

I appreciate the feedback guys.

TacoJova I hadn't even considered the FX1000 as it's not listed on CM's website, at least directly when searching for compatible clutches for the F8x. Do you know if the clutch disks were segmented/pucks or full faced? Have you noticed much in the way of clutch chatter? I'm assuming the engagement isn't too harsh if you can drive in traffic.

m3elmo To be honest I'm leaning towards the FX350 at this point, especially considered that you found it tolerable as a daily driver along with a LWFW. As the un-sprung version is apparently designed for use with the dual-mass flywheel, it might just fit the bill.

[TacoJova]

Yea the FX1000 isn't on any website as I believe it's new. I only found out about it by calling them. And I'm not really sure on your question I just know that that one of the disks was sprung to help with normal driving and less noise. Clutch chatter is more than stock but not horrible. Engagement is pretty much the same as stock is what I found only the pedal is stiffer. Stock is a twin disk also btw
Also fx1000 is strapped too

[TacoJova]

This is the Fx1000 as I hadn't seen a actual picture of it

[MJ6]

Originally Posted by TacoJova

Yea the FX1000 isn't on any website as I believe it's new. I only found out about it by calling them.

I've been emailing Andrew from CM off and on since yesterday, and I think I was initially confused as it appears that there was another FX1000 Twin Disk available previously, but it was more race oriented.

The one that you acquired is most definitely one of their newer offerings, and apparently as a 10" setup one of the most streetable twin disks offered on the market right now.

I'm double checking with my mechanic, but it looks like this might be a winner.

Thanks again man!

[TacoJova]

Yea I think they probably changed the race one to be the FX850 and the new fx1000 is the street one but still very good for high hp. And might even be better than the FX850 as the 850 is a 8.5 inch versus 10 inch. I love the way the lightweight clutch made it rev a little faster too. Seems perfect now

[TacoJova]

Btw I didn't bother with the fx350 or any others as I kind of remember them saying 600 or so hp was the limit and just wanted something that could handle anything. And honestly everyone that's driven my car hasn't noticed the new clutch compared to before so it's not stupid heavy

[bmwtrix]

TacoJova Can you provide the part numbers you got? I'm looking to go with the same setup you have! Thank you!! Also, since you've had it for almost a year, are you still happy with it?

[TacoJova]

Originally Posted by bmwtrix

TacoJova Can you provide the part numbers you got? I'm looking to go with the same setup you have! Thank you!! Also, since you've had it for almost a year, are you still happy with it?

I called by phone and placed the order and I can't seem to find the invoice in my email only the receipt but it doesn't have part numbers. And so far it's held the power. It's not the best for traffic but it's livable for me. But I'm also used to semi clutches so I wouldn't take my word for it. It does chatter a lot and will not be smooth when backing up or turning

[heitzke]

Fwiw I ended up going with the Spec twin-disc and i've honestly been quite happy with it: https://topgearsolutions.com/spec-tw...m3-m4-f80-f82/

Aside from the little "churning" noise sitting in neutral from the clutch, I have no complaints. The pedal feel is quite nice and also good to know that I'll literally never run out of holding power.

[Vertix]

Originally Posted by heitzke

Fwiw I ended up going with the Spec twin-disc and i've honestly been quite happy with it: https://topgearsolutions.com/spec-tw...m3-m4-f80-f82/

Aside from the little "churning" noise sitting in neutral from the clutch, I have no complaints. The pedal feel is quite nice and also good to know that I'll literally never run out of holding power.

Whats the clutch like vs stock for daily driving?

Is the churning noise in neutral loud at all?

Hope you dont mind me asking, tossing up between a few clutches at the moment!

[heitzke]

Originally Posted by Vertix

Whats the clutch like vs stock for daily driving?

Is the churning noise in neutral loud at all?

Hope you dont mind me asking, tossing up between a few clutches at the moment!

It's actually been really pleasant for daily use. I'd consider the pedal feel around as light a the factory unit.

The churning is definitely audible with it sitting in neutral, even with a fairly loud exhaust setup. It's loud enough for my partner to ask me "has it always made that noise?" but to be fair, there was also no music on.

With any sort of music or noise in the car it doesn't bother me at all. How do you feel about it now MJ6 ?

[MJ6]

Originally Posted by heitzke

It's actually been really pleasant for daily use. I'd consider the pedal feel around as light a the factory unit.

The churning is definitely audible with it sitting in neutral, even with a fairly loud exhaust setup. It's loud enough for my partner to ask me "has it always made that noise?" but to be fair, there was also no music on.

With any sort of music or noise in the car it doesn't bother me at all. How do you feel about it now MJ6 ?

So far I'm liking it. Compared to the FX1000 the Spec is much easier to drive on a daily basis; I feel that the FX1000 might be able to hold up to more abusive driving due to the ceramic disks over the hybrid-Kevlar on the Spec, but for everyday duties it was just too much for me.

The pedal is a bit more firm, but I also have an Ultimate Clutch Pedal installed and deleted the helper springs so that probably has a healthy say in it. At idle I can occasionally hear a little chatter, but for a twin disk setup it's barely noticeable unless you're really listening for it.

I'm still in the brake-in period so I haven't had the chance to really romp on it yet, but I'm glad I finally ended up with the Spec.

[CaTalyst.X]

Is there a way to get rid of the clutch assist with an aftermarket clutch? Seems like they might not play nicely together

[MJ6]

Originally Posted by CaTalyst.X

Is there a way to get rid of the clutch assist with an aftermarket clutch? Seems like they might not play nicely together

The Ultimate Clutch Pedal allows you to adjust where the helper springs mount, providing with either more or less assistance depending on your preference. You can also remove them entirely, which is what I did as I feel it gives a more direct feeling to the clutch pedal.

Removing the Clutch Delay Valve from the slave cylinder helps immensely as well.

[-Eidos]

Keep an eye out for the XClutch, which will be released early to mid this year for the F8X cars. I've been beta testing it for a while now and it's a serious motorsports grade clutch that is friendly on the streets with respect to the beating that it can take (Half-mile events and track days). I daily it with the Ultimate Clutch Pedal, Auto Solutions SSK at stock height with 15% throw reduction, and Rogue trans mounts.

They're based in Australia too, so that should tell you all you need to know.

[1000hp]

Originally Posted by MJ6

The pedal is a bit more firm, but I also have an Ultimate Clutch Pedal installed and deleted the helper springs so that probably has a healthy say in it.

This is the SuperTwin we're talking about?

How much more firm than stock is the pedal feel?

And what setup, if any, was required? They advertise it as a direct bolt-in with no special setup required. Is that accurate?

[MJ6]

Originally Posted by 1000hp

This is the SuperTwin we're talking about?

How much more firm than stock is the pedal feel?

And what setup, if any, was required? They advertise it as a direct bolt-in with no special setup required. Is that accurate?

Correct, this is the Super Twin SB55PT P-Trim. Pedal feel wise, as I already had the UCP installed prior to installing the clutch I couldn't accurately say how it equates exactly to the stock pedal feel. However, I can tell you since I had the UCP installed along with the stock clutch beforehand that it feels similar, and maybe just a little bit firmer.

And it's is indeed direct bolt in, no modifications necessary as it includes the flywheel bolts, TOB and alignment tool.