XClutch Twin Disc Review & Installation (6MT N54)

suspenceful

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After my Spec Stage 3+ clutch started to slip after only 5k miles at 750whp, I was forced to search for another new clutch. The Spec clutch was only rated at 671 tq, I thought it would be capable of holding more power. My search of 1000+ tq rated clutches led me to research twin disc options for the N54.

As some of you might be aware, there is a new twin disc clutch option for those of us with manual N54's. Xtreme Performance Clutch (or XClutch) is an Australian company that specializes in clutches for performance vehicles overseas. With the recent group buy, I decided to give their clutch a shot given the price is much cheaper than the Motiv or MFactory twin discs.

For more detailed information, check out my complete blog post about this topic. I also included a video at the bottom of this post that shows the noise and pedal engagement.

I ordered the ceramic version of the clutch, which is capable of holding more torque and is meant for track-driven cars. However, there is also an organic version available.

I received the clutch a few days after ordering and was very impressed with the quality! It includes the clutch & flywheel assemblies, metal throwout bearing, pilot bearing, flywheel bolts, machined alignment tool and locktite.

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I couldn't wait to get it installed! Here is the list of items I replaced while I was in there:

- Bellhousing Bolts (one-time use): https://bit.ly/2Ht7mYL
- D0wnpipe Gaskets: https://bit.ly/2w83I0R
- Rear Main Seal: https://bit.ly/2VIgzGi
- Upgraded Clutch Delay Valve: https://bit.ly/2LudXYd
- Royal Purple Transmission Fluid (2 qts): https://amzn.to/2E6O6PK
- Upgraded Brass Clutch Fork Pivot Pin: https://bit.ly/2VHh1EJ
- Poly Transmission Mounts: https://bit.ly/2sOXEJH
- Clutch Pedal Stop: https://bit.ly/2Vcjkec

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Break-in Overview

The recommended break-in mileage is 1000 kilometers (621 miles). This should include mostly city driving where you are frequently using the clutch. Racking up highway miles aren't going to help break in the clutch. I noticed that the driveability gets better and all noises quiet down a little after 500 miles. It will never be as quiet or as smooth as a stock clutch... but it's much more capable than the stock clutch.

Noise Overview

If you install the metal throwout bearing that is included with the kit, it will produce a metallic whirring noise when the clutch is depressed. This does not bother me, but it might bother some of you who don't like noise. Please watch my video at the bottom of this post to hear the noise.

The metal throwout bearing included with the kit is recommended and more robust, but this is the OEM-style throwout bearing if you'd like to avoid the noise: https://bit.ly/2Hy6rX3

As with any SMFW or twin disc, you will have low RPM gearbox chatter. While idling and while driving at high load/low RPM, you can hear it. If this bothers you, you will have to stick with an OEM-style DMFW clutch setup. Otherwise, you can raise the idle via MHD to 900 RPMs or so to reduce the chattering.

However, at power levels of 600whp+, the stock DMFW is not recommended and there are not a lot of upgraded clutch options available that mate up to the stock DMFW. I've used many different clutch/flywheel setups in these N54s, and have no qualms with the increased noise of a SMFW or twin disc. It's all part of the game when you're chasing horsepower!

Driveability Overview

I knew the ceramic version of the clutch would be a little more difficult to drive than the organic version, so please take that into consideration when reading my review or purchasing the clutch.

The pedal is stiffer/heavier than stock, but not by much. It's effortless to depress, which is good. Engagement doesn't happen until the top of the pedal during release. My stock clutch and my Spec Stage 3+ clutch both engaged a lot closer to the floor, so this took some getting used to. Installing the clutch stop helped, but still has a large area of dead space in the pedal. Again, watch my video at the bottom of this post to see how much dead space there is.

Once the engagement starts, the window is fairly small. You don't have a lot of slipping area, and this can result in a shuttering take-off until you learn the clutch. I've heard that the organic version is a little more forgiving in this sense.

The clutch itself is very grabby, just like it should be. I was getting slippage between gears in my old Spec Stage 3+ and this one grabs right away, which is great. I have no concerns about it holding any power I'm capable of making right now (750whp+).

Check out the video I put together of the clutch. It includes an install timelaspe, some driving, and my impressions of the noise/pedal engagement. If you're into BMWs or N54 stuff, give me a thumbs up on YouTube and subscribe to my channel!


Overall, it takes some getting used to but once you learn the clutch, it's definitely streetable. I drive my car frequently in the summer and am happy to have a clutch that will hold the power. If you don't have high power goals, I would recommend the organic version of this clutch. If you plan on making 700wtq+ or more, I would definitely go with the ceramic version.

I hope this thread is helpful to those who are considering this clutch, or other clutch setups. Please drop questions below and I'll do my best to answer them from an enthusiast point of view.
 

martymil

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Pretty much sums up everything I said all in one post, it will make it easier to find all the info with visual aid for new customers.
 
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fmorelli

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As usual nice write-up with lots of useful tidbits. Rear main seal simple to swap on the N54?

Filippo
 
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GGMR2T

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How do you like the Royal Purple Synchromax? I put Redline D6 ATF in mine and am wondering if that is contributing to the gearbox chatter. I've got some stock gear oil on the way so I'll find out soon enough, just wondering your thoughts. Martymil I think you said you stick with stock fluids and it seems to suit you best which is one reason I decided to switch back and give it a go.
 
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fmorelli

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I'm generally happy with the Synchromax, but went to it because I'm running a short shift kit (UUC) and my experience is those do better on BMW's with Synchromax. If you are not running a SSK, honestly I don't see the reason to run anything but factory fluid. I've not done a comparison on the N54 MT of fluids - honestly I've done so many MT SSK's on BMW's that my de facto from previous experiences is to go to the Synchromax in that case. It seems to work fine in my N54 MT setup, but don't take my commentary as gospel - just as consideration :). My car has had so many combined mods done that I couldn't tell you differences anyway. And I'm about to go to twin disc clutch, etc ... kind of like a baked German Chocolate Cake - hard to reduce it back to its constituent pieces...

Filippo
 
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suspenceful

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Pretty much sums up everything I said all in one post, it will make it easier to find all the info with visual aid for new customers.

Yup, was nice to have some tips from you in the other thread!

As usual nice write-up with lots of useful tidbits. Rear main seal simple to swap on the N54?

Filippo

Thanks! NoQuarter gave a great explanation below for the RMS.

It is. Drill small holes in the existing to insert a pik and pull it out.

Tap in the new one using the old to tap on during the insertion.

Right on!

How do you like the Royal Purple Synchromax? I put Redline D6 ATF in mine and am wondering if that is contributing to the gearbox chatter. I've got some stock gear oil on the way so I'll find out soon enough, just wondering your thoughts. Martymil I think you said you stick with stock fluids and it seems to suit you best which is one reason I decided to switch back and give it a go.

The Royal Purple seems good so far. I used it to help the 1-2 shift when WOT, but haven't tested it yet. I've used Redline MTL and D6 ATF in the past. Both were good. The MTL felt the smoothest of the 3, honestly.
 
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GGMR2T

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All good info thanks! I too am running a SSK with DSSR, M3 weighted shift knob, and replaced the rear bushing on the shifter carrier with the turner motorsport poly bushing. All seems to have increased feedback for a better shifting experience. My thought is if I can get away with a bit thicker oil to quiet the noise just a bit, but still have a good shifting experience, that's where I'll go. I think most importantly for me though, I want to rip through the gears without grind or hitting a wall. On the subject of grind, how's your "new" used tranny doing for you Jake? Or have you not had a chance to rip it yet?
 

suspenceful

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All good info thanks! I too am running a SSK with DSSR, M3 weighted shift knob, and replaced the rear bushing on the shifter carrier with the turner motorsport poly bushing. All seems to have increased feedback for a better shifting experience. My thought is if I can get away with a bit thicker oil to quiet the noise just a bit, but still have a good shifting experience, that's where I'll go. I think most importantly for me though, I want to rip through the gears without grind or hitting a wall. On the subject of grind, how's your "new" used tranny doing for you Jake? Or have you not had a chance to rip it yet?

I was previously getting locked out of 2nd or hit with some grinding whenever I'd rev out 1st all the way and try to power shift into 2nd. Only happened during WOT and redline. I haven't broken in the new clutch yet so I haven't attempted that same thing with the new transmission yet, but I'll let you know what happens when I do!
 

The Convert

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I'm generally happy with the Synchromax, but went to it because I'm running a short shift kit (UUC) and my experience is those do better on BMW's with Synchromax. If you are not running a SSK, honestly I don't see the reason to run anything but factory fluid. I've not done a comparison on the N54 MT of fluids - honestly I've done so many MT SSK's on BMW's that my de facto from previous experiences is to go to the Synchromax in that case. It seems to work fine in my N54 MT setup, but don't take my commentary as gospel - just as consideration :). My car has had so many combined mods done that I couldn't tell you differences anyway. And I'm about to go to twin disc clutch, etc ... kind of like a baked German Chocolate Cake - hard to reduce it back to its constituent pieces...

Filippo
If you enjoy driving your car, I strongly recommend against a twin disc...at least a ceramic one. I have the spec ceramic and it absolutely ruined the car for me. I actually hate driving it because my city is full of hills and pulling away from a stop is a nightmare with it.
 
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fmorelli

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I suspect that is more the ceramic (vs organic) than the twin disc ...

Filippo
 

martymil

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Mine is as quiet as a mouse and drives like stock, I ran mine in the garage as it makes the gearbox louder and there is no noise.

 
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The Convert

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I suspect that is more the ceramic (vs organic) than the twin disc ...

Filippo
That I can’t comment on. Switching to an organic has been recommended, but I’ve already replaced this clutch twice and am not spending another thousand dollars and doing the job again without driving one first. I also feel like I got screwed because I ordered the organic and was shipped the ceramic. This was all back when the clutch was first introduced to market. Not sure if any of you remember all of the snafus around that launch.
 
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GGMR2T

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I forget Marty, are you running the ceramic? And you said the TOB does quiet down a bunch? And quite possibly your gearbox is so quiet because of the thicker bmw fluid in there. Anyone know if you can buy just the replacement disks? I can slip a clutch, but there isn’t much “slipping” of the ceramic in my experience so far. If I try and slip it during engagement, it shutters and sometimes will shake the car violently. It might be a matter of “driving around it” but I’m wondering if after break in, this part gets better. I think I’m at 2-300 miles on it so far and am trying to drive city as much as I can.
 

GGMR2T

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Ok cool. I just need to be patient then haha! I’m certainly not planning on ripping this thing out anytime soon that’s for sure. Just wondering what the options down the road may be. I haven’t heard yet of anyone replacing just the disks so I wondered if that was an option. Maybe they never wear out . Probably would have to get the plates resurfaced too and that would throw everything out of spec possibly anyway?
 

The Convert

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Ok cool. I just need to be patient then haha! I’m certainly not planning on ripping this thing out anytime soon that’s for sure. Just wondering what the options down the road may be. I haven’t heard yet of anyone replacing just the disks so I wondered if that was an option. Maybe they never wear out . Probably would have to get the plates resurfaced too and that would throw everything out of spec possibly anyway?
Not sure about xclutch product, but spec ceramic does not get to a comfortable state. I have a few thousand on mine. I know you can buy replacement discs from spec, but flywheel, intermediate plate, and pressure plate surfaces are recommended to be resurfaced when switching friction material as the material needs to bed into the steel mating surfaces during break in.
 

DCook

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Not sure about xclutch product, but spec ceramic does not get to a comfortable state. I have a few thousand on mine. I know you can buy replacement discs from spec, but flywheel, intermediate plate, and pressure plate surfaces are recommended to be resurfaced when switching friction material as the material needs to bed into the steel mating surfaces during break in.
Not at all. I highly recommend against the ceramic spec as well. Mine use to be tolerable but the last month has gotten worse. It use to be somewhat slippable. Not anymore. Im hoping the xclutch organic twin disc is a hell of a lot better. I hate slipping this ceramic crap.
 
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GGMR2T

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Dcook, are you saying you have the xclutch ceramic version and it’s gotten harder to engage not easier over time?

Or you had the Spec version of the ceramic...
 

DCook

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Dcook, are you saying you have the xclutch ceramic version and it’s gotten harder to engage not easier over time?

Or you had the Spec version of the ceramic...
Spec version ceramic.