Just installed it last weekend. I don't hear the rollover noise so many complain of.. Does it manifest itself later or does it happen right away ?? Here's a few pix. I had the Dinan LWFW / HD clutch setup .. You guys can see the size differance. The UUC setup is lighter than the Dinan setup even with the bigger stuff ..Here's a few pix.
Another UUC V12 Clutch thread..
1 - 9 of 9 Posts
The rollover noise comes from the trans fluid heating up and thinning out. It only occurs when the car is hot. Just give it some time, it will show up.
Also, if the outside temps are cool, and you're using their 75w140/D4 ATF fluid mix you wont hear any rollover noise unless you've been driving very hard.
I switched back to MTF LT2 and the rollover noise increased.
Also, if the outside temps are cool, and you're using their 75w140/D4 ATF fluid mix you wont hear any rollover noise unless you've been driving very hard.
I switched back to MTF LT2 and the rollover noise increased.
The UUC setup is 11" versus the stock 9 5/8" hence the UUC has to be MUCH lighter than the stock size in order to even have the same moment of inertia. Don't forget that weight is not the only factor to comapre when you are changing the size. Depending on the radius of gyration difference between the two, the UUC 11" will need to be about 30% (or even more actually) lighter to have the same rotational inertia (moment of inertia varies with the square of the radius of gyration).
In dynamics, for evaluating the rotational inertia of an object, there is a radius where you can consider the mass to be located -- that is called the radius of gyration. You then use the radius of gyration in the equation for inertia to come up with the moment of inertia of the object. Well, the moment of inertia of a rotating mass varies with the square of the radius of gyration.
In this case, nobody knows the radius of gyration exactly since it would take some serious measurements and calculations, but we can guess it reasonably closely. It is obviously not the outer radius of the assemblies; most like the radius of gyration is roughly the inside radius of the swept area of contact on the flywheel -- somewhere in that region -- it won't be much if any closer to the inside.
So perhaps the radius of gyration is roughly 4.5" on the large UUC assembly and 3.875" on the stock assembly. That means the UUC would need a 35% lighter weight than stock to equal the same moment of inertia of the stock assembly (4.5^2 / 3.875^2). If we had a better estimate of the radius of gyration for the two, we could get a closer estimate.
People who just focus on weight are missing more than 1/2 of the problem since that radius of gyration has an exponential relationship to inertia.
Chuck
Pedal effort is the same as stock..
1 - 9 of 9 Posts
