Aluminum Flywheel: Pros & Cons?
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Racer
Joined: Oct 2000
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Aluminum Flywheel: Pros & Cons?
I'm getting everything together for my clutch change on my '94 and have been thinking about going to an aluminum flywheel. By doing so, I know that it will reduce rotating mass and allow it to rev quicker and free up some extra horsepower. I'm wondering about drivability issues(my wife may have to drive it sometime- God forbid :eek: ) What about noise? Is it considerably noisier? Those who have one on their car, is it worth it? Little info needed before I decide. Thanks
Instructor
Joined: Oct 2001
Posts: 175
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From: Wilmington Delaware
Re: Aluminum Flywheel: Pros & Cons? (Dr. Doom)
I've heard that aluminum flywheels are better for road racing because they reduce rotating mass and allow the revs to go up and down faster and steel flywheels are better for drag racing because the increased rotating mass keeps the revs up which is what you want in a drag race.
Scott Chab
Scott Chab
Drifting
Joined: May 2001
Posts: 1,630
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From: Brandywine, Chester and Ridley Valleys Pennsylvania
Re: Aluminum Flywheel: Pros & Cons? (94Hawk110)
Someone who isn't mechanically inclined would probably stall the engine the first 5 times he or she tried to start out in first gear. After that, he or she'd ensure that the car didn't stall again by riding the clutch at 3500 rpm. He or she'd also ensure that you'd be putting a new clutch and flywheel in soon.
My advice- I drove a friend's 96 LT4 six speed with alum. flywheel for a few hours on a trip. Personally, I loved it. But I'm the kind of person who would never lend his car to anyone and is willing to trade off drivability (no city driving, etc.) for performance. I also don't mind the guy next to me thinking I'm trying to race because I have to slip the clutch a bit down low to ensure a smooth takeoff.
I don't run one on my "toy" because I honestly don't see a stock TPI L98 gaining much, if anything from one. By the time the revs are high enough to see a HP gain, the L98 is running out of breath anyways... But that engine isn't long for this world, and I am certainly going to consider one with the next engine setup.
My advice- I drove a friend's 96 LT4 six speed with alum. flywheel for a few hours on a trip. Personally, I loved it. But I'm the kind of person who would never lend his car to anyone and is willing to trade off drivability (no city driving, etc.) for performance. I also don't mind the guy next to me thinking I'm trying to race because I have to slip the clutch a bit down low to ensure a smooth takeoff.
I don't run one on my "toy" because I honestly don't see a stock TPI L98 gaining much, if anything from one. By the time the revs are high enough to see a HP gain, the L98 is running out of breath anyways... But that engine isn't long for this world, and I am certainly going to consider one with the next engine setup.
Melting Slicks
Joined: Aug 2001
Posts: 2,047
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Re: Aluminum Flywheel: Pros & Cons? (94Hawk110)
Scott, what's the update on the Fireturkey repair? Was the spark advance the prob? E-mail me at EricVonHa@aol.com
Aluminum vs. Steel? Rotating mass, inertia and the laws of physics. It takes more power (torque) to accelerate (rotate) a heavier mass. You've got the same horsepower/torque available because it's the same motor, right? So it stands to reason the aluminum unit will accelerate faster. But the steel unit will rotate and carry it's intertia longer. Somebody oughta add something here coz I really cant' say that it adds a tenth to the quarter mile times, but maybe?
Aluminum vs. Steel? Rotating mass, inertia and the laws of physics. It takes more power (torque) to accelerate (rotate) a heavier mass. You've got the same horsepower/torque available because it's the same motor, right? So it stands to reason the aluminum unit will accelerate faster. But the steel unit will rotate and carry it's intertia longer. Somebody oughta add something here coz I really cant' say that it adds a tenth to the quarter mile times, but maybe?
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: Aluminum Flywheel: Pros & Cons? (EricVonHa)
Somebody told me that it would be too soft for drag racing and the clutch doesn't hold as well. I'm not sure I buy that one. Anyway, with the ZF 6 tranny if you get rid of the stock flywheel your tranny will sound like it is about to explode if you idle with the clutch out.
I've never driven an aluminum flywheel car, but it seems like the extra rotating interia would actually help some. Sure the motor will rev quicker, but it would be easier to stall and seems like the motor would absorb more punishment from the drivetrain. With less inertia to keep the motor turning it just seems like it would get jerked around a lot more as your drivetrain speeds change. Note, the last two sentences may be complete :bs That's just what I think about it, could easily be dead wrong for lack of first hand experience.
I would have to drive one before I could make a decision, but it just doesn't seem like the best idea for a daily driver.
I've never driven an aluminum flywheel car, but it seems like the extra rotating interia would actually help some. Sure the motor will rev quicker, but it would be easier to stall and seems like the motor would absorb more punishment from the drivetrain. With less inertia to keep the motor turning it just seems like it would get jerked around a lot more as your drivetrain speeds change. Note, the last two sentences may be complete :bs That's just what I think about it, could easily be dead wrong for lack of first hand experience.
I would have to drive one before I could make a decision, but it just doesn't seem like the best idea for a daily driver.
Melting Slicks
Joined: Dec 1999
Posts: 2,816
Likes: 2
From: Austin, TX
Re: Aluminum Flywheel: Pros & Cons? (Dr. Doom)
I've had an aluminum flywheel in for almost a year now. Personally, I love it. But I also love weekend roadcourse events. Here's my experience:
-engine revs quicker, easier to match RPMs when up/downshifting (after you get used to it
-Get one with a steel friction insert (don't know if they make them without), clutch grabs just as well as with stock FW
-I went with 3.73 gears because the 3.45's made it a bit tricky going up ramps / hills from a standstill
-A bit noisy at idle with the clutch out (I don't mind, but my girlfriend thinks it sounds broken)
-any engine vibrations you have will be more noticable (the factory flywheel does a good job of masking small vibrations)
-Make sure you get the FW balanced to match your stock FW (LT1's are externally balanced) regardless of if the manufacturer says it's already balanced.
-engine revs quicker, easier to match RPMs when up/downshifting (after you get used to it
-Get one with a steel friction insert (don't know if they make them without), clutch grabs just as well as with stock FW
-I went with 3.73 gears because the 3.45's made it a bit tricky going up ramps / hills from a standstill
-A bit noisy at idle with the clutch out (I don't mind, but my girlfriend thinks it sounds broken)
-any engine vibrations you have will be more noticable (the factory flywheel does a good job of masking small vibrations)
-Make sure you get the FW balanced to match your stock FW (LT1's are externally balanced) regardless of if the manufacturer says it's already balanced.
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Racer
Joined: Oct 1999
Posts: 467
Likes: 1
From: Lufkin tx
Re: Aluminum Flywheel: Pros & Cons? (Dr. Doom)
I should be able to comment better on this in a couple of weeks. Still waiting on the clutch to come in and then I will be testing the aluminum flywheel. There was a good post in the Engine Mods section about the effects of rotating mass.
