Welp, my Spec Stage 3+ clutch started to slip after only 5k miles at 750whp so 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. There is also an organic version for those of you who might not need the 1350 tq rating.
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.
The recommended break-in mileage is 1000 kilometers (621 miles). I noticed that the driveability gets better and all noises quiet down a little after putting on some miles. It will never be as quiet or as smooth as a stock clutch... but it's much more capable than the stock clutch.
Noises:
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.
Driveability:
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 have no concerns about it holding any power I'm capable of making right now (750whp+).