Aftermarket that is? Looking to buy me that street twin and was wondering if it is neccesary to buy the flywheel as well?

 

10-15 Less rotating weight you got it!! They say its hard to take off i didnt see a difference. Less is more haha.

 

You need to do a flywheel with the ST due to the extra three bolts that hold the floater disc in place. I imagine you could machine your stock flywheel for those three fasteners, but I'm not sure it'd be worth the hassle.

 

the lighter the FW the worse off you are. when you dump the clutch all the monentem (acctually angular momentem) in the rotating assembly and FW and are put to the drive train all at once. so now you have less weight that is all ready in motion which means it is easier to stop spinning. so lees power is being put to the ground and the moment you dump the clutch. but there is and affect when your moving, once your rolling the engine taht is lighter will accelerate faster, less weight to rotate.

take a 1 lbs brick on the end of a 5 foot rope and swing it arround and around and try to stop it, not to hard. now do it with a 15 lbs bowling ball. it a little harder to stop. but once you get the brick moving you accelerate it faster than you can the bowling ball. it better to look at it this way you engine is not trying to rotate the drivetrain the drivetrain is trying to stop the engine from spinning and the lighter the rotating mass the eaiser it is to stop.

a perso that is going to drag race would want to the heaver FW the person road racing wants a lighter FW.

just food for thought

 

good points. so how does the weight of the pressure plate play into all this? would it help or hinder in drag racing. for example, would a regular LT4 pressure plate be better than a lightened SLP pressure plate?

 

Only true if you can get down the 1/4-mile without shifting. Otherwise, you need to slow the engine down to shift, and afterwards you need to accelerate the engine back up towards the shift point again. That takes power to do so.

Given that, I still run a steel flywheel on my car - doesn't make much sense to do otherwise, as a 4200 lb car with a bit of cam and a lightweight flywheel wouldn't be much fun in stop-and-go traffic. But I still think you need to buy a new flywheel when going with a Street Twin, unless you modify your stocker to mount the floater disc.

 

Contrary to popular belief, a lighter flywheel is beneficial in drag racing. MMFF did a test on 3 different types of vehicles. Stock, lightly modded, and highly modded. Each car was faster with a lightweight flywheel. Granted, this is true if you have your traction under control, and can launch at a higher rpm and not incur wheelspin. The slight loss at the start of the 1/4 is more than made up for by the shifts and gain in acceleration.

 

The light weight flywheel question haqs to be the second tossed around qhestion with the MAF...Some guys race hardcore with the Aluminum...some prefer steel. what ever works I guess...people that drag run Aluminums with the "scatter shield" and some just lighten the steel up to a billet....

<-----awaiting Billet flywheel!

 

Mt point of veiw on this whole subject is you want your engine to slip a lil on take off to cure spin and bogg, If you run a stout clutch its gonna pull your motor down more than the light fw will.