Lightweight flywheels
 

Hello,

It is time for me to change my clutch which is a ceterforce dual-friction. I have to say that centerforce is a good product since this clutch has been in two different mustangs, is 8 years old and has been through some serious ABUSE. It's time to replace the clutch now though and while I am at it, I'm thinking of picking up a lightweight flywheel. The stock cast iron flywheel weights almost 29lbs. I have read that he aluminum is around 13- 14 lbs. and I'm not sure on the billet steel. What is everyone's opinion on the matter? Which would be the best?

Re: Lightweight flywheels
 

i dont have much experience with clutches and all that matter ...since most of my cars are auto's but if you think about it - the lighter weight of the flywheel will mean that it will take less to turn it meaning less loss of power through the drivetrain, and on top of that you are also losing a bit of weight on the overall car.

Re: Lightweight flywheels
 

Dont run a lightweight flywheel unless you are running alot of gear.

Most mustangs lose alot of low end grunt and even run slower with a lightweight flywheel. The inertia generated by the flywheel really helps you get off the line and keeps rpms up between shifts.

I also cosidered getting a lightweight flywheel last year and after alot of research i decided against it.

Re: Lightweight flywheels
 

The flywheel is there to keep the engine running as it fires and smooths out the impulses. The flywheel is heavy for the inertia of the spinning of it to get the weight of the car moving.

If you go light the car will lose bottom end. I don't think it will make up enough at the higher RPM to overcome the bottom end lost.

I wouldn't do it.

Re: Lightweight flywheels
 

just out of curiosity, wouldn't the lighter weight get the engine spinning faster though, enough to pull right past the low end loss?

Re: Lightweight flywheels
 

Upon acceleration, As soon as you push the clutch in on the shift, you fall out of the powerband quicker, but running alot of gear could fix that.
I say do whatever you want to do, and post about it:) I can see how the alum flywheel would help power once the car is already moving, but the launch would be better with a steel flywheel for obvious reasons.

Re: Lightweight flywheels
 

There are certain set-ups were it would. 8000rpm low geared race cars.

I researched this topic very heavily last year and asked the opinions of some very smart guys and they all said I would run slower.

I then Googled the hell out of results for light weight flywheels and I found an article that totaly made me against doing it. I found a post were a guy built his motor with a lightweight flywheel and was unhappy with his 1/4 mile times. Thinking it may be the lightweight flywheel he reinstalled his stock flywheel and cut a much better 60ft and picked up 2 mph cause the rpms didnt fall so bad betwen shifts.

Re: Lightweight flywheels
 

I'm gonna throw what I've learned at ya, take it for what it's worth.

I'm running a 609 flywheel HP (N/A Baby!!) small block, and my tranny guy told me that I DO NOT have enough horsepower to run a lightweight flywheel!

Sure, that killer smallblock you have will spin that sucker up FAST and get you into the next gear Faster than Gen. Grant went through Richmond. The only problem with that is what was stated in this thread already.

As SOOOON, and I repeat, as SOON as you hit that clutch pedal, that engine is gonna fall on it's face just as fast as it spun up when it was in gear and you had your foot in the water pump.

Like the guys are telling ya, unless it's a 9K high gear race car, stay away from it!!!

Re: Lightweight flywheels
 

Ok, how many people posting in this thread have actually track and dyno tested aluminum versus steel? How many have just read about it?

After testing out my combinations and my friends, I have probably been involved in testing this theory at least a couple dozen times. Then there was the magazine article written by David Vizard that was originally in MM&FF and has since been republished in PHR, that I was part of. Plus the experimental testing I did for QuarterMaster, I think I'm plenty qualified to speak on this subject.

The most important factor is vehicle weight. Supporting factors are horsepower, torque, rpm, tire size, tire material, rear gear ratio, ratios in the trans, and what type of racing you are doing. Theres an infinite number of possibilites of all these factors, and for every combination there is an ideal clutch/flywheel weight.

However, of the couple dozen combinations I have been a part of testing, not one of them ran slower with an aluminum flywheel.

We have tested Mustangs that weigh 3000 to 3330lbs, blown, n/a, rear gears from 3.73 to 5.13, RWHP from 320 to 650, 2.92, 3.27, and 3.35 first gears, slicks and drag radials: They all ran faster with an aluminum flywheel. And they could have all gone faster if we had the time and money to to find the ideal weight for the clutch/flywheel combo. There is definately a point where they will get too light.

Andy

Re: Lightweight flywheels
 

Good to see you again Andy!

OK, so I'm going to interpret this as I was only half correct. Possibly for MY combination, Walt is telling me to stay with steel, NOT "stay with steel" in general? I know ALOT of guys running aluminum wheels, and having great sucess with them!

Did that make sense? LOL

Re: Lightweight flywheels
 

I know a guy with a 99 cobra that uses an al. Flywheel, I realize that is a modular, whole different animal, also they are known for having no bottom end, well this cobra did pretty good with the aluminum flywheel and 4.10's, even down low....just some of my experiences.....good luck