Anyone know if an RX8 manual trans flywheel will fit and FD?

Thanks in advance,
David

 

Yes, from the literature I have read, the FC Turbo II, FD and RX8 (FE?) all share the same flywheel dimensions.
http://mazdatrix.com/flywheel.htm

 

Not 100% sure but, the both are based off the same 13B block so i'm pretty sure it quite possible, it will probably boil down to how the trans is bolted to the Body of the vehicle, cause as you probably know, FD's are bolted up wierd lol

 

I'm curious why you'd want to put one on a Rx-7? Whats the weight of a stock Rx-8 flywheel? (and price)

 

Yes same flywheel, different counterweight of course.

 

Why?

 

Reason: My flywheel has heat cracks and I found an cheap RX8 flywheel for sale.

 

yea it will work i have a rx8 flywheel in my FD

 

I have a exedy rx7 flywheel on a rx8.

 

Wow there is some poor advise in this thread. Just becuause it fits, doesn't mean it should be used. If your talking manuel tranny Rx8 flywheel then yes it will fit. BUT your rotating assembly will be way off balance. Rx8 rotors are lighter than Fd rotors. All Mazda rotary factory manuel tranny flywheels have the counter weights built in and are balanced for the rotating assembly of each individual engine. Swapping these these around will cause the rotating assembly to be un-balanced. You then run the risk of more engine vibrations and accelerated bearing wear. At the very least you should be looking for another Fd flywheel or a 2nd gen Rx7 S5 turbo II flywheel. S5 turbo II rotors weight the same as the Fd rotors. The balance will still be off some but you will be closser than using the Rx8 flywheel.

 

wow didnt think they were all interchangeable

 

Very good points about it not being balanced for this car's engine, why not pick up another stock FD flywheel? Im sure you could find one for extremely cheap....

 

Yep even a 12a 1st gen flywheel will fit. You would have to do some major rebalancing then use a NA clutch disc and pressure plate so it would mate to a NA tranny input shaft. If you know what your doing, you can mix many rotary parts.

 

Hmm...

So what happens when you install a lightweight flywheel using the automatic counterweight?

 

the flywheel with now counterweight is evenly balanced.

[quote=t-von;9655036]Wow there is some poor advise in this thread. Just becuause it fits, doesn't mean it should be used. If your talking manuel tranny Rx8 flywheel then yes it will fit. BUT your rotating assembly will be way off balance. Rx8 rotors are lighter than Fd rotors. All Mazda rotary factory manuel tranny flywheels have the counter weights built in and are balanced for the rotating assembly of each individual engine. Swapping these these around will cause the rotating assembly to be un-balanced. You then run the risk of more engine vibrations and accelerated bearing wear. At the very least you should be looking for another Fd flywheel or a 2nd gen Rx7 S5 turbo II flywheel.%

 

using the auto counterweight will give you the same balance as using the stock manual flywheel so everything will be in balance like before.

 

I have the rx8 and I went threw everything with doing my FD 5 speed swop. I got the aftermarket flywheel cause mine was wore out. Just like what's been said the counter weight is totally different. Go to any site that sells the aftermarket flywheels and the counterweight will be different. It will slide right on and bolt right up. Just like I'm going with the FD rotors in my rx8.

The counter weight is for the off balance of the rotor's. The FD rotors are lower compression and a lot heavier then the rx8's. There for DIFFERENT counter weights.

 

Uh....what?

What exactly does flywheel interchangeability have to do with "how the trans is bolted to the Body of the vehicle"?
How exactly are FDs "weird" compared to other vehicles?

 

Also just so you know not only are the rotors lighter but the e-shaft is half a pound lighter. Sounds like a really bad idea if you dont have the whole rotating assembly balanced.

 

You mean it will get you close to the "same balance". The auto counter weights are also balanced to the individual rotating assembly as well. You have to remember that 13b rotors have 5 different weights for the rotors. "A"-"F". "A" weights being the heaviest while "F" being the lightest.

Example: You have a 5speed Fd 13b. You decide you want to go with a aftermarket light weight flywheel. Finding a flywheel isn't a problem but you have to find the correct counter weight for your Fd engine. The only problem with this is you will never know what rotors weight your engine has unless you open it up. But lets just say your engine has "A" "B" rotors already but you find a counter weight off an engine that had "E" "F" rotors. Guess what??? your engine will be out of balance if you use that counter weight. Now since were talking street car, this imbalance isn't really going to be a major thing because the engine isn't going to be running for sustained hi rpm's.