Light Fly Wheel Details
 

Just curious some information about installing light fly wheels.

I have heard plenty good things about adding this mod, but realize there are positives and negatives. So I am trying to make some consumer decisions.

1. A light fly wheel apparently adds responsiveness to the throttle. Anyone have ball park or specific numbers to torque and HP (to the wheels) gains?

2. How much does a fly wheel's weight affect the smoothness of the Renesis engine.

3. I hear stalling is a common biproduct. Is this true?

4. There are several different weights advertised for RX8 fly wheels. Which is the best bet...and are there name brands that have better history than others.

5. Is it a good idea to upgrade the clutch if you lighten the fly wheel. Where would I find a good place for that.

6. Anything else I should be aware of?

Thank you in advance!

Re: Light Fly Wheel Details
 

I can answer some of these, as I've been thinking about getting one of these myself...

Less than 10 WHP, but the engine spools up so much quicker that it is effectively more power than WHP alone can justify. Same power over less time to wind out fully = more effective power.

Should not have much of an effect.

Only until you get used to the new character of how the clutch letout feels.

You want the medium weight for the street... not the "racing" super-lightweight one.
Vivid Racing.

Yup... installation is ex-pen-sive. You're looking at $500+ at most shops. A really good installation price would be $350.

This is one of those mods that I plan to do After the car is out of warranty. I figure that by that time, I will probably need a new clutch anyway, so the installation cost is the same.

go with the MS flywheel and have it installed at the dealer. with the quirks of this tranny, it will be worth it in the long run to keep your warranty.

A light flywheel does not add power! It does mean that the engine does not have to use power to spin the flywheel and that amount of power is directly related to the rate of acceleration (engine not car). A light flywheel will allow the engine to respnd faster. This can be both good and bad. Anyone going from a old original RX7 to the 8 will notice how much easier it is to stall the 8 and how more sensitive it is to throttle at initial start up (I sure did). This is because when you let the clutch out the light flywheel of the 8 has less rotating energy and the engine slows down faster than a 7. Also when you touch the throttle the engine speeds up quicker. This is not because the 8 mkes more power than the 7 as the 7 & 8 make almost the same power below 3000 rpm. If you go to an even lighter flywheel then it will be harder for you to make your start and shifts when driving easy.

Motorcycles have for years used the flywheel to help tune for the various ridding conditions. Road racing and motocross they use almost no flywheel while for off road and especially trials where fine clutch action and stalling are critical they install heavy flywheels.

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