JHM R Series Clutch and Lightweight flywheel review

[jwr9152]

Well you can see my mods in my signature, the big one obviously being the APR Stage 3 supercharger. The only real issue that comes along with the supercharger is the need for an upgraded clutch. The stock unit cant handle the increase in horsepower and torque. I decided to go with the JHM stage 4 clutch and lightweight flywheel, it's a good combination for the street. The lightweight flywheel really frees up the engine and revs build and drop very quickly. If shifting slowly, a throttle blip between gear changes really smooths things out. I don't drag race, but I do autocross so I do launch my car at starts. The stage 4 clutch engages better then the stock unit, but still has a fatal flaw of the oem unit, that being the self adjusting pressure plate. While the clutch can easily handle repeated launches, the pressure plate seems to be a weak link, and starts behaving erratically. The clutch engagement point starts changing based on rpm's.

So, I decided to upgrade to the R series clutch. It is a 6 puck sprung clutch with a non self adjusting pressure plate. It takes 500 miles of city driving to break the clutch in, and it is not a pleasant 500 miles. A lot of chatter unless you absolutely drop the clutch. Not always an option in city driving. Honestly there was not a lot of improvement in the clutch during the break in period, but after the first 500 miles and once I started being a little more aggressive with it, the clutch began to get better and better. I have over 1000 miles on the clutch now, and have run it in 2 autocrosses. It is fantastic on launches, very smooth and engages very quickly with no slip. Now that it is broken in and I have learned how to drive it better, it is very smooth everywhere. Still takes some concentration off the line to be smooth if you are going slow, but it is much better then the stage 4 clutch everywhere else. Up shifting and down shifting takes no thought and there is nothing special you have to do to be smooth. I don't notice any increase in pedal pressure, and like it a lot better then stock. It really is a good clutch, and looks like it is going to be a good match for the extra power.

[Rusty Axle]

Just curious - at what rpm are you launching at. And is it a quick drop of the clutch? I have a 2013 manual with stock clutch and have often wondered what kind of impact a hard launch would have on the driveline.

[jwr9152]

I'm usually between 2000 and 2400 rpm's. I just drop the clutch and feed in throttle as wheel spin allows. To me it doesn't seem near as hard on the driveline as the B8.5 with launch control.