Aluminum or steel flywheel

[blykins]

Yep. Tolerance stacking. Sometimes the Scat cranks are a tad oversize, sometimes the flywheels are a tad under.

I used a Fidanza aluminum wheel on my 428....the flywheel had to be touched inside to get it to fit correctly.

[CobraEd]

I love my RAM aluminum flywheel!!! You can also get pressure plates with aluminum rings and save an additional 5 lbs. I wish I woulda done that too:

http://www.speedwaymotors.com/Ram-10...ord,33276.html


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[PANAVIA]

I like Steel Flywheels, they are durable and tractable. Aluminum can spin faster , but that is just an additional expense I just cant see on a street car.

[DAVID GAGNARD]

Originally Posted by PANAVIA

I like Steel Flywheels, they are durable and tractable. Aluminum can spin faster , but that is just an additional expense I just cant see on a street car.

Zacctly, any motor will "wind up" a little quicker with a lighter flywheel, be it steel or aluminum......I doubt the average guy could really tell the difference, probably looking a a few tenth's of a second.........Unless your all out racing, there is no need for the extra expense of an aluminum flywheel....IMHO of course......

And I have 2 Mustangs with one flywheel of each,I driven both quite a bit........

BTW: there are steel flywheels out there that are almost down to the aluminum weight for about 60% of the price of an aluminum wheel.......

David

[CobraEd]

The motor winding up faster is not just some interesting anecdotal side effect. If the engine winds up faster when running full throttle in gear as it will with an aluminum flywheel, that means the car is accellerating faster. It is a waste of hp trying to spin up a 30lb disc from 1,000 rpm to 6,500 rpm as fast as possible. It takes a lot of HP that could be going to the rear wheels. It is a parasitic loss. Think of all the time, money, and effort spent in building up our engines for maximum power. The $100 differnece to get an aluminum flywheel over steel of cast iron is a small price to pay for 1/2 second off your 1/4 mile times as indicated in one of the posts above, or for blowing off the competition on the street. It is free hp that is no longer being wasted trying to rotate a 30lb mass.


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[DAVID GAGNARD]

Originally Posted by CobraEd

The motor winding up faster is not just some interesting anecdotal side effect. If the engine winds up faster when running full throttle in gear as it will with an aluminum flywheel, that means the car is accellerating faster. It is a waste of hp trying to spin up a 30lb disc from 1,000 rpm to 6,500 rpm as fast as possible. It takes a lot of HP that could be going to the rear wheels. It is a parasitic loss. Think of all the time, money, and effort spent in building up our engines for maximum power. The $100 differnece to get an aluminum flywheel over steel of cast iron is a small price to pay for 1/2 second off your 1/4 mile times as indicated in one of the posts above, or for blowing off the competition on the street. It is free hp that is no longer being wasted trying to rotate a 30lb mass.


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I wont dispute the above graph showing 1/2 second in the quarter mile runs, but look at the dates on the graph, one year apart.....Assuming all things were the same, that's some big gain....I'd have to get more info on the car, yes, it had the same engine, what what about tires, were they the same, weather conditions, same or not, weather alone will play a factor in 1/4 times. driving will also.... One could assume the driver was a better driver a year later and that alone could account for some of the lower ET.......

I've run both flywheels on the street and on a road race car as well as a dirt track car and never saw more than 2/10's or so better times......definetly something you could not feel by the seat of your pants.......

I'm having a 460 CI FE built for my ERA with 428 block and steel heads. It will be a torquer and not a radical motor. The builder is suggesting an aluminum flywheel - but mostly because that is what everyone wants. This car is a street roadster recreation and will be strictly street driven by me. I'm questioning if I really need and aluminum flywheel for this and wouldn't be better off with a steel flywheel. What are most people using with a mild to medium build big block motor?

The original question was what to put in the car, "This car is a street roadster recreation and will be strictly street driven by me."

For that use, I'd still recommend a steel flywheel.......JMHO of course....

David

[DougD]

Originally Posted by DAVID GAGNARD

BTW: there are steel flywheels out there that are almost down to the aluminum weight for about 60% of the price of an aluminum wheel.......

David

I agree w/David - pick a lighter weight steel version. Instead of deciding between an aluminum and a steel flywheel, decide whether you want a light or a heavy flywheel. There are vast differences between the different brands, from a featherweight 12-15 lbs to 40 or more. You can't just narrow it down to the two materials they're made from. Given the fatigue characteristics of aluminum vs steel, I'd pick a lightweight steel one every time over an aluminum one. Ask your builder what the weights are for the brands and materials you're considering.

[DAVID GAGNARD]

Right now I have 2, 65 Mustangs, one is a 3200 lb. street car with a standard/stock steel wheel, 3.25 rear gear ratio, I can putt-putt around town in 2cd and 3rd gear at 1000 rpms all day with no problems, no jumping/bucking/spitting/caughing, that car is a pleasure to drive....

The other is a 2700 lb. road race car,3.70 rear gear, 13 lb. aluminum wheel and I can't putt-putt around the paddock in 2cd or 3rd gears at 1000 rpms, it'll buck and kick eveytime.....I wasn't going to put an alum. wheel on that car till the machine shop offered me a brand new one still in the box for 100 bucks, I couldn't pass up that deal......seems they had that and a few other parts along with a block they machined for a guy that never came to pick up his parts nor pay the bill, so the shop was selling off the stuff to recoup money.....

back in my dirt track days we tried an alum. wheel, the car did come off the corners a little crisper, then the track outlawed alum wheels, so we expiremented with taking weight off stock steel wheels... We were running a small block Chevy at the time and you could get stock steel flywheels at any junkyard for 5 bucks a piece.....we had 5 to 8 at one time....we drilled a bunch of holes in some and in one, we turned it down on a lathe and then drilled holes in it and got it down to 12 pounds....I was afraid it would explode, cause it was soo thin and didn't want to drive the car with in it.....I split seat time with a buddy and he drove the car with that wheel the last half of the season with no problems/failures........

I WOULD NOT recommend to anyone to do what we did, it was down right crazy/stupid and dangerous, but we were young and bullet proof, or so we thought....

Normally, small block steel wheels weight in around 30 pounds, aluminum from 12 to 15 depending on brand, I've seen some new steel wheels advertised in the low 20 pound range and to strike a happy meduim, I would use a lightweight steel wheel for the reasons DougD listed above.........

David

[RodKnock]

Isn't a steel flywheel about $250 and an aluminum flywheel about $500? Assuming that's about right, isn't worth getting an aluminum flywheel for additional $250? Makes sense to me in a Cobra.

EDIT: It seems to me, and maybe only me, that when building an FE, the $250-$300 or whatever is just a "rounding error."

[CobraEd]

As I recall, my RAM unit was about $300 about 2 years ago from Jegs. In a light car like a Cobra it makes a huge difference. In a heavier car, not so much. I putt around at 1,000 rpm all the time, very smooth. Take off from lights just off idle, no reving or problems.


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[blykins]

I can do a RAM steel flywheel (for an FE) for about $275, or a PRW steel flywheel for an FE for $225.

For aluminum needs, I usually push the Fidanza. It has all pressure plate patterns and is the lightest (14lbs) between RAM, McLeod, and Centerforce. I can do it for $350.

For small block cars, I have some awesome deals on steel wheels.

[RodKnock]

So, $75-$125 difference. Hmmm.

[Rwillia4]

there might not be a clear answer but there is some good information and opinions along with some hard facts. In any case it has me thinking hard...

[spl310]

There is a third option that has not been discussed - lightening the stock flywheel. I know of several guys that had failures with aluminum flywheels. None that I recall off hand were catastrophic - but they were enough of a failure to take the car off the road for a while. A steel flywheel is more durable. A lightened steel unit gives you the best of both worlds.

[ENTDOC]

I used a lightweight steel flywheel, a good compromise for our cars. 20lbs I think

[undy]

It would depend on what your definition of "lightened" is. If it's a factory made "lightened" unit, OK. But ... if it's done at a local machine shop then it scares the hell out of me. If it was SFI rated, then that rating is gone plus ... it could be very d-a-n-g-e-r-o-u-s.

[CobraEd]

Heaviest = old style cast iron
Medium = Steel
Lightest = Aluminum


My RAM aluminum flywheel is SFI rated. I guess that is good, but I don't know specifically what it means


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[undy]

Originally Posted by CobraEd

Heaviest = old style cast iron
Medium = Steel
Lightest = Aluminum


My RAM aluminum flywheel is SFI rated. I guess that is good, but I don't know specifically what it means .

In case you're still wondering...

"What Do the Letters "SFI" Stand For?

SFI was originally a foundation run by SEMA, the automotive aftermarket trade organization. The letters "SFI" stood for "SEMA Foundation, Inc." Although SFI is now completely independent from SEMA, the Foundation has retained the name SFI Foundation, Inc. but the "S" no longer means SEMA.

Who Uses SFI Standards?

Manufacturers of equipment are the primary users of SFI standards. Some standards are adopted as part of the rules of race sanctioning organizations. Ultimately, the consumer benefits from the program as it establishes recognized levels of performance or quality for a product.

How is the SFI Standards Program Funded?

Participating manufacturers pay for development and administration of these programs through licensing fees and/or unit charges. Also, interested associations have provided grants and donations.

How is a Standard Initiated?

The SFI Technical Committee initiates the specification process, typically at the request of the affected industry or race sanctioning body.

How is Participation Obtained?

SFI encourages industry-wide participation in the drafting of specifications. However, once a standard is enacted, participation by the manufacturer is strictly voluntary.

What About Enforcement?

Typically, there are policing provisions through contractual or licensing agreements whereby SFI may inspect the records and/or equipment of a manufacturer in order to ascertain that the product involved meets SFI Specs. Once a manufacturer has voluntarily committed to participating in the program, it must comply with the specifications in all respects.

How Are the Specs Used in Racing?

When adopted as part of the rules of a race sanctioning body, enforcement is entirely up to that organization. The manufacturer then provides the racer with product that is in compliance with the specs enforced by the sanctioning body.

All contents of this website Copyright 2005 by the SFI Foundation, Inc. All rights reserved."

[FatBoy]

Originally Posted by CobraEd

Heaviest = old style cast iron
Medium = Steel
Lightest = Aluminum

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Not necessarily.

The cast flywheel (C8AE-A) originally fitted to my 427 weighed in at 20lb. The shiny new McLeod steel flywheel weighed in at a hefty 40lb.

Paul