MR_Fisher

Hey guys, did you know SPEC makes a light weight billet aluminum pressure plate option for the 8? I saw the option on the website looking for clutch details and wondered why they don't make one for the RX-8, so I emailed them reminding them that some older models had the same specs and they responded immediately stating they DO in fact make one and that it is now listed.

http://www.specclutch.com/cars/Mazda/RX-8/2005/Single

I am going to reply back and ask exactly how much it weighs and if the clamping force is more than stock like their standard pressure plates. I was thinking of doing a swap to a light flywheel and new pressure plate, keeping the stock friction disc.

MR_Fisher

Well, ****. That sucks. I used a SPEC stage 3 six puck on my last car and loved the way it felt and engaged, I had just assumed this was an "upgrade".

I am definitely not swapping over to a part with a 75% failure rate. Thank you for sharing your experience.

champi0n

iTrader: (1)

I have a spec stage II on my other car and within less than 2,000km it started slipping. Oddly the stock clutch managed to survive much longer.

I spent like $600 to downgrade my clutch to a SPEC, only to replace it with the stock one i took off in the first place... go figure.

-WILL-

so are you saying a lighter flywheel or pressure plate will make the car harder to drive? if so, why?

staticlag

In a normal Manual transmission car, the clutch pressure plate and the flywheel are heavy, partly because they use cheap materials but also because it makes it easier for the average joe to drive.

With lightened components you achieve an ultra responsive car, the problem is most people aren't good enough at shifting to make this useful.

http://www.youtube.com/watch?v=w5OrO...feature=fvwrel

So for people who are poor at shifting its a pain and very jerky, for those who are precise at shifting it makes the car a joy to drive.

The car on the right has only a lightweight flywheel, it would be much faster revving than this with the light clutch.

MR_Fisher

It's not just that one has to be 'precise' at shifting, it also entails a loss - a compromise if you will, like all modifications. The purpose of the flywheel is to keep the engine rotating after power is cut (i.e.: throttle closed) so that it doesn't just drop to zero RPM immediately and helps keep the forward momentum going. When you lose alot of that forward momentum, it is more difficult to make the car move smoothly. Many are not willing to sacrifice that.

My machinist told me not to do both a lightweight flywheel and knife edge the crank (removing unnecessary weight from the crankshaft counterweights) in my last car because he felt it would not be streetable due to the loss of momentum. I, however, loved the way it revved, didn't mind the loss of momentum, and had no problem starting from a stop.

MR_Fisher

Also, to threadjack myself a bit...
staticlag - how is the 4.777 gear compared to stock? Does 1st seem too quick? What did your top speed drop to?

ssspeedfreak

iTrader: (1)

I have the BHR stage II light weight option Charles is speaking of and this thing is super sweet and performs as I believe Charles intended! I hope this last a very long time! In fact a just installed a rebuilt tranny and the installer said it looked fine, I wish I would have been there to take pics but no, sorry Charles! I also have the ignition and radiator upgrade, love the BHR stuff! To bad it didn't work for many others.

ssspeedfreak

iTrader: (1)

That means I have a limited edition BHR exclusive were the only other product exist is at BHR themselves! Priceless! Lets see the new seven stock stuff!

andrewhelmus

Sorry to revive such an old thread, but I was wondering if any type of lightweight pressure plate products might possibly be in the works, either from BHR or other manufacturers?

I'm certainly interested in reducing the rotating mass much like you did with your car. 4 lbs is a nice reduction, but I think almost 8 lbs would be pretty great!

I have a Miata with a lightweight flywheel and I love it! It's a must-have with the RX-8 now..