Fidanza Aluminum Street Rant Thread

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This thread is probably not what you thought.

Those who run or have run the Fidanza aluminum flywheel on your street car that had problems with them...


What was the problem and what did you do to fix it?
 
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I put one in my LX when I did the AOD/T5 swap because it was the thing to do. I hated it from the second I backed the car out of the garage for the first time. On my car, it basically felt like the clutch pedal was an on/off switch. There was no in between. After f-ing around trying to "get used to it" for a week, I swapped in a stock flywheel and never had another issue.
 
I put one in my LX when I did the AOD/T5 swap because it was the thing to do. I hated it from the second I backed the car out of the garage for the first time. On my car, it basically felt like the clutch pedal was an on/off switch. There was no in between. After f-ing around trying to "get used to it" for a week, I swapped in a stock flywheel and never had another issue.

Make sense, since there's so much LESS rotational weight. The OEM plate's inertia carrying through the friction of contact longer than the lightweight piece would.
 
so its just the fact that the rpms move too fast for most because its an aluminum flywheel?

whythors: when you said it felt like an on/off switch that makes me think of the clutch and not the flywheel itself. how did it seem like an on/off switch to you?

i need to replace my stock clutch and was thinking of using an aluminum flywheel. guess ill do more research first.
 
so its just the fact that the rpms move too fast for most because its an aluminum flywheel?


I don't think so. It's that there's so much less rotational mass that when the clutch plate makes contact that the flywheel's rotation is stopped that much easier.

Where with a steel flywheel... it weight carries further and causes a good 'slip' on the friction surface before the two finally match speeds (engine and flywheel to clutch assy and rest of driveline).

The whole purpose of the flywheel is to basically insulate the engine from the shocks of the rest of driveline. So I'm on the fence about whether lighter or heavier is best.

Anyhow... what I really want to know is about the kinds of problems folks have had how they were dealt with.
 
How much faster is an aluminum flywheel anyway? Say, how much time can you expect to drop in the 1/4?

I've always been curious, never seen before and after results, though.

My buddy who is a multiple Wally winner was saying for drag racing to stay away from aluminum flywheels cause it kills your inertia off the line, or something like that, wasnt really paying attention since im a turn burner :lol:
 
so its just the fact that the rpms move too fast for most because its an aluminum flywheel?

whythors: when you said it felt like an on/off switch that makes me think of the clutch and not the flywheel itself. how did it seem like an on/off switch to you?

There was almost no slippage to make for a smooth engagement. The clutch was either engaged or it wasn't. No in between.

An aluminum flywheel has a replaceable, semi-metallic contact surface, much like a brake pad. It is much "grippier" than a metal surface. Once I was moving, the shifts were fine. It was just the starting from a stop that was a PITA. Also, I couldn't tell any difference in driveability with the lighter flywheel. Not sure what all the fuss about them is. You can get a Ford Racing cast iron flywheel for about $90. The Fidanza aluminum unit is over $300. You can get your stocker resurfaced for about $15.
 
There was almost no slippage to make for a smooth engagement. The clutch was either engaged or it wasn't. No in between.

An aluminum flywheel has a replaceable, semi-metallic contact surface, much like a brake pad. It is much "grippier" than a metal surface. Once I was moving, the shifts were fine. It was just the starting from a stop that was a PITA. Also, I couldn't tell any difference in driveability with the lighter flywheel. Not sure what all the fuss about them is. You can get a Ford Racing cast iron flywheel for about $90. The Fidanza aluminum unit is over $300. You can get your stocker resurfaced for about $15.

Less rotational mass
 
There was an article in hotrod magazine a while back about what's new in clutches... and they touched lightly on aluminum flywheels. The general message was that a steel or iron flywheel with more mass would naturally provide more torque for a launch. The difference in weight between a steel and aluminum wheel is half. They went on to say that heavier cars like old 57 chevys, impalas blah blah should stick with steel because they need it to get out of the hole.
In contrast, the lighter cars, i.e. fox mustangs, with big cube balanced strokers already make big torque, and benefit more from the acceleration than suffer from the small loss of torque.

That's hotrod- not me. but those guys have been around racing since before I was born and I'm an old fart.

It's a good idea imo if you're turning a lot of rpm's to at least use steel, because iron can and will explode, and it ain't purty. I've seen it.
 
Yes this is the same reason I don’t run aluminum rods, the steel rods help me launch harder.:rlaugh:.

I have built a few engines and come from tractor pulling where you would think a heavy flywheel might be great when the sled at the end of track is trying to pull the engine to its knees. We run as light of a rotating assembly as possible it will help to get it off the line, note the engine that I have tested this on is turning over 6000 rpm's. I have actually seen better performance at the end of the track using a 40lbs lighter flywheel.

Also I mountain bike, why is it that I perform better when I put on my lighter set of wheels?

If you want to really find out for sure look up Newton's laws of motion, specifically 3rd law.

Scott
 
.....not sayin' don't run aluminum.... just don't try to wind up an iron flywheel too high as it can eff yer feet up when it comes thru the floorpan.

again, with the hotrod article, that's their commentary, not mine. I'm going aluminum.:D

I think what they meant was the inertia of that heavy ass flywheel helps keep the rpm's up on initial launch with a mild motor in a lead sled.

a massive engine in a tractor pulling rig puts out so much torque anyway this theory kinda goes out the window....
 
I could see how folks who are having trouble getting traction off the line might go to aluminnum flywheel. I can see two benefits:

Less rotational inertia = less initial shock to the driveline = lowered chance of breaking wheels loose at the line

Less rotational mass = Less power required for engine to rev = Higher RPM at exit line


Advantages I can see for steel or (better yet) billet steel:

Harder launch on sticky tires (harsh on driveline)

Brunt of shock from clutch drop is taken by that heavy rotational mass vs. being taken by crank and engine internals.
 
How much faster is an aluminum flywheel anyway? Say, how much time can you expect to drop in the 1/4?

I've always been curious, never seen before and after results, though.

i dont think you could do a black and white test like that, my car on radials seemed to work well with the aluminum clutch cause i dont think it shocked the tires as hard, but when i used slicks this year it would bog pretty hard on anything under a 6000rpm launch. I put it to about 6400 rpms on the rev limiter and launched it and it still bogged a little but i was able to run a 1.49 60' so i wasnt terrible. I think if i had a steel flywheel with the slicks i would have been better off

My buddy who is a multiple Wally winner was saying for drag racing to stay away from aluminum flywheels cause it kills your inertia off the line:

this is true