I was looking for the usual bolt-on parts for the RX-8 and saw that Unorthodox Racing is working on an aluminum flywheel. Being an ex-RX-7 owner I know that you need a counterweight when replacing the stock flywheel with an aftermarket one. This required me to order a counterweight from Mazda when I did the aluminum one for my 7 and they are not always available (had to wait for a while to get it). But now it looks like UR has integrated it into the flywheel... way cool!! Anyone ever see something like this? This pic was taken from their site...

Looks promising. Unorthodox makes some quality transmission componants from what I have heard. I haven't heard about the counter weight however. I didn't even know you needed to counterweight a lightened flywheel. Seems to ruin the point.

You will need a new counterweight with that flywheel. Counterweights are usually around $110. Both ACT and Racingbeat are making flywheels which will be cheaper than the unorthodox.

Jason
www.rx8store.com

The counterweight actually doesn't have anything to do with the flwheel, it has to do with the rotors in the motor. There are counterweights in the front and back. When you remove the stock flywheel, the counterweight is cast into it. So you have to replace it.

Jason, that flywheel INCLUDES the counterweight. It is that steel part embeded in the back! I'll give them a call today and see if they have any pricing...

Just called UR. The guy there said the flywheel is about a month away from going into production, maybe sooner. I also confirmed that it has the counterweight embeded into the back and will include all hardware. He said pricing is $539 and that there will also be the version for the RX-7 (different weight in the back). Sounds cool to me!

That sounds like a quality part for a decent price. Thanks for the update man.

No problem... any suggestions on clutches?

I think a lightened flywheel is exactly what this engine needs.

I hate when upshifting fast, and the engine doesn't wind down fast enough to match the revs. That equals clutch wear and jerking in the car.... very dangerous if you actually have to shift in a corner on the track.

7 posts, and not a single mention of how much weight exactly the LIGHTEN flywheel is saving and how much more hp is that gonna pull??

It will probably save you 10lbs off the stock flywheel. Wont add HP but will let the engine rev quicker.

Jason

M-ster, I totally forgot to ask! I think the RX-8's flywheel is somewhere around 19 lbs.? I thought I might have seen that in a post somewhere. I don't see a weight on their website. I'll drop them an e-mail. Mazda has definately gotten lighter over the years. My old 88 TII I think was something like 27 lbs....

Most lightweight flywheels are in the 9.5lb range

Jason

His posts mean nothing!

Why don't you contact UR and ask them for some more stats?

Here's a linky for your convenience.
http://www.unorthodoxracing.com/mazda_rx8.html

and here's their contact page!

http://www.unorthodoxracing.com/contactus.html

Stock RX-8 flywheel: 22 lbs.

UR Flywheel w/counterweight: aprox. 14 lbs.

UR Flywheel on its own without any hub or conterweight: 9 lbs.

They said the exact weight will be determined with the production run and which counterweight is required depending on if it is a 3rd gen or an 8. The gains in acceleration are like taking 100 or so pounds out of the car... he started getting into the rotational mass thing and moment of inertia. I just want to know it will be faster! I can tell you that a lightened flywheel made a really nice difference in my 7...

Good info!! thanks for posting it up ;)

Was hoping for a little feeback on clutches to match up to the flywheel... any suggestions? UR said they will have one... what about experiences with ACT or Clutchmastes...

I don't know much about buying aftermarket flywheels, but is it necessary to buy a new clutch with the new flywheel or will it work just fine with the factory clutch?

im don't see whyit would not work with the factory clutch......however if you were planning on installing a new flywheel, might as well install a new clutch while the trans is dropped.

I would imagine the stock clutch is good... but a turbo or supercharger would make things a little different...

Just thought I'd revive this thread. For the record, the UR flywheel has the counterweight built in, and altogether weighs about 14 lbs. Does anybody else have the UR flywheel?

Jeff

I've seen a prototype of this flywheel in person as it was being assembled off the mill, and it looks exactly like the picture shows. Basically, it's a 13B flywheel that is mostly compatible with previous RX motors, but has a weighted arc about 3/4 of the way around the outer face which serves as the counterweight. 14 lbs sounds about right for this unit.

Alternately, you can make your own lightweight flywheel setup by purchasing an aluminum flywheel for a 3rd gen RX-7 as well as the counterweight for an automatic 3rd gen.

in the us when you say 3rd gen do you mean fd? In .au 3rd gen would be the last incarnation of the origional rx-7 shape.

Yes, my apologies. By "3rd gen" I am referring to the FD3S.

ACT is making a carbon clutch for the RX8, I would go with a clutch/flywheel set up while the car is down, kill two birds with one stone.

Actually, the flywheel on the car has been a source of trouble for many people so I would advise a change along witht he clutch. Also, you have a good setup for a turbo if you so desire it.

UR is making clutch kits for the RX-8 as well.