Turbo-Geist

I tried this over in the C5 Performance area but got zero responses after a couple of days. Hopefully there will be better luck in here.

I'm looking for advice from those who have used a manual transmission with a C5 or C6 corvette to run 9.99 or quicker.

The goal is to accelerate off the line as quickly as possible and be able to shift as quickly as possible using a stock 6060 transmission.

All things being equal, which is better, aluminum or steel flywheel with a manual transmission at the drag strip and at runway racing events?

Turbo-Geist

I'm looking for pros and cons, advantages and disadvantages.

I've had an aluminum flywheel for the last 8 years starting with the stock combo all the way to the 427 TT combo now. I need to make a decision and I'm trying to decide if I should stick with aluminum or go to billet steel.

In this case, going to steel would add ~14lbs to the rotating mass of a 10" twin disc assembly. ~ 41 lbs vs 55lbs. My last setup was 38 lbs, but I'm switching to something with more capacity.

Billet steel flywheel weighs ~27lbs
Aluminum flywheel weighs ~13lbs

inspector12

Well I haven't used an AL FW as you know in a vette or even a high HP car only a few all motor F-bodies. But like I said in your other thread 100% without a doubt the steel FW will net you better 60' times! That weight will help you with your taller geared 6060 to get out of the hole! The weight of the FW doesn't affect shifting speed only acceleration speed, meaning after the clutch is re-engaged. GL!

winters97gt

Exactly what I told Ben. My 60ft's on a stock driveline and drag radials are just being replicated with high hp, drag setup, corvettes with more power and drag wheels/tires, so many years later.

Ben is a smart guy, and you've been at the forefront of the LS scene since the beginning. Y'all will get it figured out sharing info. Got a lift close to Ben that we can swap out a clutch in a couple of hours before Pump Gas if needed.

Ben will drive the pants off his car, just need to get the non existent quality control of old clutch companies under control.

stevieturbo

Hard to compare though.

Your old clutch was a normal style, with a large diameter steel cover ? Placing more weight at the larger diameter ?

Your Spec has a steel flywheel...but the cover is alloy and smaller diameter.

So actual mass of the components, isnt as important as where the mass is on the diameter of the parts.

So the two may not be vastly different if you can calculate that.

Someone over on tech ( in the manual trans section ) did some calcs for an ultralight setup vs a heavy one, and any performance gains were barely measurable. Yes they did have some numbers attached, but they were very small.

For me, for a car that gets used regularly I really cant see any benefit in moving to a very light setup.. There's no doubt the heavy flywheel will drive nicer and launch far easier too.
That said, if you have good launch control strategies ( or a crude 2 step ) then flywheel weight might be less of an issue.

But also consider that the smaller diameter Spec clutch will also be grabbier on the takeup vs your McLeod, so a little extra flywheel weight might be helpful when driving too.

Turbo-Geist

Good points

The RXT 1200 weighed 38 lbs and had a 13lb flywheel so it's parts were 25 lbs and 10" nominal disc size.

The Spec is a Super-Twin so it is also in the 10" nominal disc size. It's parts weigh 28lbs. So there is a very slight MOI increase with the Spec clutch.

The steel flywheel was 14# heavier and I agree it would have added an additional MOI increase, but I'm not if it would be significant. I read threads where people had to go from a 10# flywheel to a 40# flywheel to see a measurable difference in the quarter.

I had to make a game time decision, so I went with what I know for now. These cars are time consuming to swap clutches in without a lift and special driveline supports. I would rather stay the course and not know what I'm missing than choose something and not like it and want what I don't have anymore.

Mark offered to help out with access to a lift and free labor. I really appreciate it and may take him up on it down the road. My weekend is jam packed with my daughter racing her soap box derby car Saturday and Sunday.

I started the clutch install last night and will continue tonight and hope to be done by tomorrow so I can give my full attention to the soap box races. Next week, I'll get the break-in miles on it and then drive to Dallas for the Pump Gas Invitational. #c5life