Aluminum flywheel

V

Vetteski

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Joined
Jun 13, 2008
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6
Location
California
I am autocrossing and I am needing a new clutch and I want to go to the lighter flywheel and clutch. I have talked to Ram and McCloud tech guys and I wondered if any of you know more about it and or have done it. My car weight is 3260lbs and I have the ZZ4 engine with the hp at 355 torq at 405. My trans is the Richmond Super 5 speed with 2.89 first gear and 3.70 rear gears for a total of 10.963 for the first gear. I understand the lighter flywheel removes the weight that helps you start the car rolling but then really helps your car in the braking and accellerating out of a turn. My question is how much is too much and if there is a formula to use. I have looked at the Ram dual disk 9 1/2 " and also the 168 tooth aluminum flywheel with the 1/4 " replaceable insert but what I am not sure of is would it be better to have a good gripping clutch or a more stock type due to the take off and having to slip the clutch more. I autocross more than I drive it but I drive it to the tracks and home again.
 
A lighter flywheel reduces the inertia of the rotating mass. RPM moves up and down faster. The drawback is there is less of that inertia to help get it rolling.
I have a 12 pound flywheel on my BB.
 
TimAT said:
A lighter flywheel reduces the inertia of the rotating mass. RPM moves up and down faster. The drawback is there is less of that inertia to help get it rolling.
I have a 12 pound flywheel on my BB.
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I would be scared shitless of any ALUMINUM flywheel.....to me that's just asking for troubles I don't wanna wear....

:hissyfit:
 
What about the nodular lt1 flywheel?

Sent from my GT-I9000 using Tapatalk
 
I have a Fadenza Lite weight flywheel in my 70, with a Richmond and 3.36 rear gear, used Ram clutch and Press Plate, much better drivability. will accelerate harder in the higher gears. I have 3.27 low gear, the lite weight wheel is a good match with that. I would go this route, you will gain all round. Make sure that if you go with an aluminum flywheel you get one with a steel insert on the friction face. On the reliability issue, my set up has been in the car since 2005, aprox 50,000 miles, of hard use with NO issues. I drive my car , it is NOT a Sunday cruiser.
 
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Carb Doc said:
I have a Fadenza Lite weight flywheel in my 70, with a Richmond and 3.36 rear gear, used Ram clutch and Press Plate, much better drivability. will accelerate harder in the higher gears. I have 3.27 low gear, the lite weight wheel is a good match with that. I would go this route, you will gain all round. Make sure that if you go with an aluminum flywheel you get one with a steel insert on the friction face. On the reliability issue, my set up has been in the car since 2005, aprox 50,000 miles, of hard use with NO issues. I drive my car , it is NOT a Sunday cruiser.
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OK, another learning experience...I would have never guessed....

:clobbered:
 
Carb Doc! I would like to know do you have a big block or small block and what is your power like? I ask because I am close to your gearing and I would like to know the power your engine puts out, and the weight of the flywheel that you have, if you have the reciept. I just don't want to have to say shoulda or coulda I would like to get it right the 1st time. Thanks guys for the imput it all helps!
 
I used a Fidenza 198681 Flywheel 13.5 lb with a 1045 steel friction surface, Ram 3000 series pressure plate, Ram 300 series Disc and their Release bearing. If you go this route and there is substantial mileage on your clutch rods I would urge you to pull them out of the car and inspect for wear before putting a high pressure pressure plate, you may find that the main clutch rod from the pedal to the Z bar is worn at the clutch pedal end, I built all new bars , everything on Rod ends, did the same with the bottom rod to the Fork, all rod ends again, this has proven to be adsolutely bullet proof over the years. You will want to retain your GM clutch fork as it is much stronger and a slightly different shape than the replacement ones from Ecklers or any of the others is too light and is not up to the task, you will have to make a slight modification on the clutch fork to accomodate the rod end, very easily done.
 
look for a 153t aluminum flywheel instead of a 168t, the lighter and closer you can get the "mass" to the crank centerline the better...........the following from the Quartermaster catalog:
What Is Moment Of Inertia (MOI)?
Moment of Inertia, or MOI, is a measurement of how much energy it takes to spin an object. The heavier or larger the object
in diameter, the harder an object is to accelerate or decelerate. If two objects are the same weight and one is half the
diameter of the other, then the smaller diameter object will accelerate and decelerate faster with less overall energy being
used. This translates to a faster acceleration coming out of a turn, and a faster deceleration going into the next turn. Faster
acceleration = Speed advantage over the competition
 
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My 355 puts out 456 hp at 6200, is not on the track, is more or less a daily driver, with my setup it runs 68.4 mph at 3000. I have a solid flat tappet cam in the car right now which is a bit lacking on low end torque, next service will put back a solid roller , will end up with substantially more low end torque and will likely change back to a 3.23 or 3.08 rear gear to try to pick up a bit of highway mileage. Redvetracr is right on with his advice, as I see your car is on the track, mine is Highway use only.
 
Carb Doc said:
as I see your car is on the track, mine is Highway use only.
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if he didn`t drive it on the street I would have suggested a 5.5" triple disc clutch possibly with a reverse drive starter, the difference between that and a conventional clutch/flywheel is like night & day, although I have heard of guys driving a 7.25" triple disc on the street they really don`t like to be slipped, it`s either in or out, I was advised not to even drive mine into the trailer and never have.
 
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I've got a button flywheel and 7.25 clutch. Made a very noticeable difference

I've got another button flywheel for a piece rear also, brand new, I had to get a custom made one for the magnesium bell housing I have.

You just use a auto transmission flex plate, you can even get a lightweight one of those also

I don' know If I'd want to drive with a 7.25 clutch on the street though. They are pretty cheap used on ebay from a nascar though
 
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