Ok, so a quick history on me is I've raced the hell out of my 05 Evo MR since about the 5k mile mark. At 7500 miles, right after winning an Import Bracket race at the drag strip where I made 12 passes in one day all in the 12.2-12.4 range (~40 total drag runs), my stocker started slipping. I then put in an ACT street disk that lasted 9500 miles and over 100 drag passes, the vast majority of which were 12.5 or better along with 8-10 autocrosses and two 2-day track events.
After the ACT started slipping, I got the new Exedy 4-puck to see if it would be a good single disk alternative, since there doesn't seem to be a reliable single disk on the market for less than $1000, and we already know the Exedy Twin is awesome. So, I received it and had a local shop named Revolutions Tuning install it while refilling the t-case/ACD with OEM fluids, and the tranny with BG II (wasn't able to get the Super Diaqueen in time).
First impression was that it was extremely grabby and difficult to drive. I stalled it a few times getting started in 1st and was having trouble changing gears without a clunk or jerk due to the lack of slippage. After 350-400 miles, it was feeling better in the shifts and getting easier to engage from a stop, then I went to the drag strip. It grabbed like crazy on the launch, so I was ripping my tires through first while using the 2-step. I eventually launched a little lower and got a semi-decent 60' en route to a 12.47. Due to altitude, my power is way down, and I have to shift to 5th due to the loss of power up top. However, thanks to the 4-puck, I'm able to shift extremely fast with the greatest of ease. Not only can I shift very fast, but I found that I could No-Lift-Shift every gear effortlessly. That was this vid here:
Exedy 4-puck shifting #1
The next day, I competed in the SCCA-RM 1st Summer Series Event and placed 2nd. I spent most of the time in 2nd, but I did have to a sem-launch and then do a snapshift to 2nd just before some esses. I stayed in 2nd until the end where there was a double 90-degree bend that required a downshift to 1st. I was able to do all this no problem on the Exedy and was pretty fast.
I then drove the next few weeks and found the clutch to break in further as the starting in reverse became no problem at all as did the shifting and downshifting. The only slightly difficult part is starting from a stop without a little jerking. I just have to get the revs up higher than usual so that it can slip off to a smooth start, but it's worth it for the racing performance.
That's when I went BACK to the same drag strip with the same mods except for putting on some new summer tires (Azeni RT615) in place of my winter tires (Blizzaks). My traps were the same, but now that I've figured out the launching a little better and know already that I can powershift with ease, I was able to cut my best ET down by .17s to a 12.30, which is good for no power gain. That got me this run here:
Exedy 4-puck Shifting #2
So far so good, but I have much more testing to do on this. I will be going to the road course on Friday all day for an open track session, so I'll get to see how well it holds up and shifts during long sessions of running hot. My ACT at this track last time was grdining during most of the shifts, so I was choosing to shift slower than normal. I'll see how it does in upshifting, but more importantly in downshifting engagement after hard braking.
Btw, this clutch can be had for just under $1000, and that price includes a chromoly flywheel, throwout bearing, pressure plate, 4-puck sprung cerametallic disk, and alignment tool.
I have the spec sheet for the 4-puck vs the Hyper Single and stock Evo clutches, but it's too large too attach and is a PDF that can't be loaded to Photobucket. Here's the typed numbers, though:
Clutch---------------------OEM-----Hyper Single------4-puck
Clamp (lbs)---------------2093--------3010------------3010
Road Race (max wtq)---250-----------374-------------432
Drag (max wtq)----------201-----------297-------------347
