*Michael.*

I have always wanted to do this if I ever had to change my clutch but the fact that I owned a Euro spec car that I couldn't bring back prevented me from ever really looking into it. Now that I have the US spec 944 coming over to Germany I am wondering if the benifits are really worth it. I understand that it reduces the rotating mass and which means less work for the engine. Does it make a decent difference. Does it make the engine rev a bit more freely? Any expereince or info would be great.

led

I've no personal experience with this but have been told by some friends, non of them p-car drivers, that the engine will rev faster but the top speed decreases by a couple of miles. <img src="confused.gif" border="0">

*Michael.*

[quote]Originally posted by led:
<strong> the engine will rev faster but the top speed decreases by a couple of miles. </strong><hr></blockquote>

That seems weird....... Anyone??

Hans

Engine will rev down faster while shifting, no (noticable)change to top speed.
Price: less stable to rough low RPM (idle)
My 0.000002 (euro)cents: not worth the trouble if the car is for mainly street use iso dedicated track racer.
TakeCare

JGriff

I asked this of my tech the last time my car was in the shop, and he stated that it will help the engine rev easier/faster (and make the car a bit quicker), but it will impact everyday driveability.

How so? The engine will also rev DOWN faster, which means that the shifter is not matched anymore to the engine rpms. (From the factory, the stock flywheel is matched to the throw of the shifter i.e. it drops at a rate relative to the length of time it takes to shift between gears.)

I suppose a short shift kit might help, but otherwise you may have to blip the throttle upon downshifts. That could be quite a nuisance in everyday driving.

I've thought about doing the same the next time my car needs a clutch, but I think before I do so, I will try to find a car that has had the lightened flywheel installed, talk to the owner about their experience, and try to take a drive in it to see how much of an effect it has on daily driving.

Hope that helps.

smokey

I have a lightened regular flywheel, and the main difference is that the engine increases and decreases revs more quickly under zero load. Lightening the flywheel decreases the moment of inertia of the rotating mass, and as a result, its rotational speed increases or decreases more quickly. The only advantage I can see is that it's slightly easier and quicker to shift. It wouldn't make any measurable difference to acceleration of the car or to top speed. The total inertia of the car is an order of maginitude higher than the inertia of the flywheel, so the only effect you feel is being able to blip the throttle more easily and quickly, especially on a downshift. But with a very light flywheel, you don't want to slip the clutch too much, because the flywheel has less mass to absorb heat, and you can overheat the clutch more quickly.
On balance, I enjoy driving the car more on the track with a lightened flywheel.

*Michael.*

Thanks for the info, I guess it isn't really something to do with a street car.