Thinking of using something like this for my 4.9 swap. Do any of you have any experiance with or know anything about these?

http://www.tiltonracing.com...age=list2&id=167&m=d

Here is another one. This says for chevy V6. Look under button flywheel in the dropdown menu.

http://www.racingclutches.com/content/product.asp

[This message has been edited by Fieroseverywhere (edited 04-15-2007).]

FastIndyFiero got one for his project car https://www.fiero.nl/forum/F...2/HTML/055858-6.html

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3.4L S/C 87 GT www.fierosound.com
2002/2003/2004 World of Wheels Winner &
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If it matters to you ... in general, multi-disc clutches are not a good choice for use on the street. They tend to be pretty notchy ... as in on/off ... in operation.

quote Originally posted by Marvin McInnis: If it matters to you ... in general, multi-disc clutches are not a good choice for use on the street. They tend to be pretty notchy ... as in on/off ... in operation.

I thnk you misunderstood what I was talking about. I plan on using a SPEC stage 2 or 3 clutch built by SPEC for use on a Fiero. My question is about the flywheel. A button flywheel is basically a flywheel that doesnt have any teeth for the starter. It bolts to the flexplate to engage the starter. Because of the smaller size and the fact that it can be made out of alluminum you can end up with a much lighter weight unit. This is as much as I know about them so far. Hope this helps.

I am just wondering if anyone has any experiance using them?

Fierosound: Thanks for the link, but I need more info then that. Any one else?

Here is a pic of one. I just not sure what size will work.

[This message has been edited by Fieroseverywhere (edited 04-15-2007).]

As fierosound mentioned I got one for my project. I'll try to explain some things about them...
First off, button flywheels are generally one piece units that serve as the friction surface for the clutch. This excludes them from being made from aluminum (although I have seen very few with steel friction inserts).

Secondly, the advantage of running a button flywheel is reduction of moment of inertia. In this case it's the polar moment of inertia around the same axis as the crankshaft. MOI is basically mass times distance from the axis. A reduction in MOI will result in faster acceleration, because less of the engine's output is being used to accelerate the given object instead of the wheels. So a flywheel with the same mass but with 4" smaller diameter will improve acceleration. But part of the advantage of a button flywheel is the smaller-diameter multiplate clutches that go with them. With a sufficiently strong input shaft and button, clutch torque holding capability can be increased (basically) by increasing the number of disks in the clutch. Because of the smaller diameter, the added weight doesn't cost you as much in acceleration.

But there are tradeoffs. A smaller diameter clutch is more sensitive to excessive slipping, and like what has behn mentioned, generally require a heavy or long clutch pedal. Drivability issues besides that occur as well, because the larger mass of the boat anchor they put on fiero engines serves to dampen things like a rough idle, and make it easier to launch.

I'm going to use a 5.5" 3-disc clutch, perhaps carbon-carbon if I hit the lotto. I'm also going to try trans-mounting the starter so I can use a clutch cover-mount ring gear to further reduce MOI. This should give me a total weight between the ring gear, clutch, and flywheel of about 8.45lbs, and a HUGE decrease in MOI.

The picture that you posted appears to be a 5.5" flywheel, which I would not recommend for the 4.9. A 7.25" clutch would be more suitable, especially for street use.

Hope this helps!

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My Web page | The Turbo Super Duty Build.
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quote Originally posted by Fieroseverywhere: I thnk you misunderstood what I was talking about.

Yes, I understood ... but perhaps I didn't express myself clearly enough. "Button flywheel" implies a significantly smaller diameter than stock ... which means a smaller clutch diameter ... which means less friction, and thus lower torque capacity ... for which the solutions are either heavier springs and/or multiple discs, and usually the heavier springs by themselves aren't enough.

quote Originally posted by FastIndyFiero: the advantage of running a button flywheel is reduction of moment of inertia. ... But part of the advantage of a button flywheel is the smaller-diameter multiplate clutches that go with them. With a sufficiently strong input shaft and button, clutch torque holding capability can be increased (basically) by increasing the number of disks in the clutch. ... The picture that you posted appears to be a 5.5" flywheel, which I would not recommend for the 4.9. A 7.25" clutch would be more suitable, especially for street use.

Exactly.

[This message has been edited by Marvin McInnis (edited 04-16-2007).]

Sorry for any misunderstanding. I was looking at the 7.25 or larger anyway. I found a company (ace engineering I believe) that has 8, 10, 10.5, and 11 inch. They also have single plate clutches. I'm still not sure what the Fieros standard size friction plate is. I know the clutch is 9.25 or you can use up to a 9 11/16 out of an S10. I was thinking for street use it would make more sence to use a bigger one with a street clutch. I am just trying to figure out if they would work. Makes sence to me that if used with the caddi flexplate it would give you a good amount of friction material without the extra weight. Most of the ones I have seen are made from Billet Steel. They should be very strong and lightweight. One of the problems I've run into is that nobody that sells them has any prices listed. I have an 88 flywheel but don't like the idea of plugging and re-drilling holes if I don't have to. I also heard from Captn Fiero that LSC in California will make one for 215 shipped. This is a new, not re-drilled, flywheel.

As I suspected, I just found a couple for arounnd 125-140 (5.5 inch as low as 60, 8.5 for 80) dollars which makes them less inexpensive the going the custom flywheel way. I can't find any reason why these wont work great with a street clutch. Does anyone see any reason why this wouldn't work?

Here is the link to Ace performance. They have street versions.
http://www.ace-mfg.com/html...ds/aceracing2004.pdf

[This message has been edited by Fieroseverywhere (edited 04-16-2007).]

I am using a Quartermaster setup. Right now it is triple disk but is too think so i will be switching back to twin disk.

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By:Custom2M4
in process-12" front brakes using '88 calipers and '88 brakes in rear
hybird '88 rear suspension
3400 bottom end, 2.8 Falconer Race heads, 60-1 BB turbo, A/W IC

quote Originally posted by Coinage: I am using a Quartermaster setup. Right now it is triple disk but is too think so i will be switching back to twin disk.

How does it work for you? Are they noisy? Are they streetable? Is there allignment issues or any other problems that I should be looking out for?