{"id":4097,"date":"2012-11-25T22:23:51","date_gmt":"2012-11-26T06:23:51","guid":{"rendered":"http:\/\/grandmighty.com\/?p=4097"},"modified":"2012-11-26T00:08:23","modified_gmt":"2012-11-26T08:08:23","slug":"act-hdss-clutch-prolite-flywheel","status":"publish","type":"post","link":"http:\/\/grandmighty.com\/2012\/11\/act-hdss-clutch-prolite-flywheel\/","title":{"rendered":"ACT HDSS Clutch & Prolite Flywheel"},"content":{"rendered":"
The pursuit of more power can only be achieved when supporting mods are firstly established. That’s why I decided to move forward with a clutch replacement. The stock clutches on RX-7’s are a weak-link as they are only good until around 300 HP before slipping. Picking which replacement clutch to go with wasn’t easy, I ultimately narrowed my choices down to an ACT Heavy Duty\/Xtreme Duty or an Exedy Twin Plate. <\/p>\n
Typically, I’m all for overkill, but you have to choose more carefully when it comes to clutches. I heavily emphasized NOT sacrificing drivability. The ACT Heavy Duty pressure plate with Street Disc clutch (HDSS) stood out as being the most reasonable choice. It supports up to 400 ft\/lbs of torque which should be sufficient. The actual clutch is a full-face unit, and not a puck style so this will aid both drivability and longevity. I decided against going with the Xtreme pressure plate because I think it would make the clutch pedal too stiff and it may be too taxing on the RX-7’s clutch hydraulics in the long-run.<\/p>\n
<\/a><\/p>\n I also wanted to change out the flywheel and went with the 9.5 lbs ACT Prolite.<\/p>\n <\/a><\/p>\n To ensure that this clutch job is as thorough as possible, I called up Ray @ Malloy Mazda and ordered all possible oil seals, an automatic counterweight (required to install an aftermarket flywheel), and a new clutch fork. I ended up buying one too many seals, only the rear main seal and transmission tail-shaft seal were replaced. Like the seals, the clutch fork was primarily preventative maintenance and also complimented the stiffer pressure plate. I read that they fatigue and crack, especially the earlier ones from ’93 cars. Mazda later strengthened them with I guess better casting. Lastly, I found a steel braided clutch line that I bought almost 4 years ago and never had a chance to use until now. <\/p>\n <\/a><\/p>\n I like to work on this car myself whenever possible because I want the control; however, sometimes you just need to enlist the help of a shop. I’m sensible enough to realize that wrangling off a transmission on my garage floor is beyond my scope. Instead, I brought the car over to the knowledgable folks at P R Motorsports<\/a>, who specialize in Mazdas and, specifically, have done work on RX-7’s. <\/p>\n When I dropped the car off, I didn’t overextend my stay and left for work relatively soon… still, I think the owner, Laura, was keen enough to sense my paranoia and criticality. Throughout the day, she sent me numerous updates and pictures. I’ve never had a shop do that for me before, which was very cool and I definitely appreciated the thoughtfulness. <\/p>\n Here are a couple pictures from the shop. <\/p>\n