Flywheel Alum vs Iron

[ERA 626]

Bob,
Flywheel Alum vs Iron

Bob,
I started a thread on a Alum flywheel vs a steel one and what is your opinion on this??
Peter said my ERA 427 S/C is going to start construction in Jan.
Have you guys assigned me a # yet?
My name is Mike Lagrone
Thanks,
Mike

[Bob Putnam]

Mike,

Personally, on a street car I wouldn't use an aluminum flywheel unless I had to replace the one that came with the engine. It's nice to lose the rotating inertia, but I have reservations about the longevity of the clutch face - some designs are better than others in that respect but I'm not an engine expert.

When Peter calls you for the second installment, he'll tell you the number. I don't know nuttin' bout the production line unless there's something that requires my alleged expertise.

[ERA 626]

Bob,
Thanks for the reply, Is there a size that I need for my ERA (184 tooth?)
Mike

[Bob Putnam]

I didn't even know that there was more than one ring gear choice before you asked the question... I'm pretty sure that you want the 184T gear with a manual trans, but maybe someone out there is an expert. We're on holiday shutdown, so Doug is not here right now.

[CobraEd]

It seems that for around town use the aluminum flywheel would always be better. At any speed, if you floor it, your revs will come up faster and the car will accelerate faster because there is less inertia to overcome. So if you are cruising along next to a guy with a new Viper on the highway at say 55 mph and you floor it, you will accelerate faster with the aluminum unit because there is less inertia to "spin up".

A heavy steel flywheel is better for drag racing only (not any racing, only drag racing) because you spin up the engine IN ADVANCE OF THE RACE while still at the line to say 5,000 rpm. Now you have this heavy flywheel spinning at 5k, you dump the clutch and all that inertia works with the engine torque to help keep the revs from dropping for a good launch. Then when you hit 2nd and third (4th??) the spinning inertia again helps keep the revs up for more forward thrust at each full throttle shift. So this is good for a drag race.

On the street, you dont dump the clutch at 5 grand everywhere you go and speed shift at max rpm every single time you shift. You want the ability to spool up fast from any speed/rpm including low rpm cruise for fast acceleration from any speed/rpm.

Ed

[ERA 626]

Ed,
Thanks for the explanation!! That is the advice I am looking for (smoke the viper)
Mike

[CobraEd]