Clutch Match Balancing
Heel & Toe
Joined: Nov 2005
Posts: 19
Likes: 0
There is really only one way to do it "right" if you are at all concerned about flywheel/clutch balance: Take the flywheel, PP, PP bolts and washers to a good shop (the one I use can balance to 1/10th of a gram, closer than anyone could possibly need!) and have them zero balance the flywheel alone. Then have them attach the PP and rebalance to zero, removing/adding metal as needed on the PP portion only.
This way, if you have to change the PP in the future, you can have just it balanced, without being forced to re & re the flywheel as well.
This way, if you have to change the PP in the future, you can have just it balanced, without being forced to re & re the flywheel as well.
Racer
Joined: Nov 2003
Posts: 451
Likes: 1
From: Ringgold Ga.
Originally Posted by Cobra4B
worthless post 
Last edited by rplaster; Nov 18, 2005 at 07:02 AM.
Team Owner
Joined: Mar 2001
Posts: 25,889
Likes: 7
From: Virginia Beach
CI 3-5-6-7-8 Veteran
Originally Posted by TT_Vert-
let me tell you what a corvette tech and I discussed a few months back. Mind you he does JUST corvettes and seems very competent. I have done 99.9% of the work on my car and only brought my car in for warranty so I feel I am a good judge of competence. What he does is such:
He notes the spots on the stock flywheel that has weights on it. He marks those spots on the new flywheel he puts in. he does NOT put those weight on until after he test drives the car and noticed a vibration. THEN and on THEN, IF there is a vibration, he takes that black plastic cover off the front of the bellhousing (not the inspection plate) and inserts one weight at a time and repeats. With that said, my new LS7 setup didnt need any weights and I have no vibration or balance issues. Ditto w/ the LS6 clutch I put in last year. The way he does it, the H pipe does not need to come down every time you want to insert a balance weight.
Dave
He notes the spots on the stock flywheel that has weights on it. He marks those spots on the new flywheel he puts in. he does NOT put those weight on until after he test drives the car and noticed a vibration. THEN and on THEN, IF there is a vibration, he takes that black plastic cover off the front of the bellhousing (not the inspection plate) and inserts one weight at a time and repeats. With that said, my new LS7 setup didnt need any weights and I have no vibration or balance issues. Ditto w/ the LS6 clutch I put in last year. The way he does it, the H pipe does not need to come down every time you want to insert a balance weight.
Dave
So it's better to just pull, match balance and re-install. BUT, for a factory flywheel w/ the holes that's damn smart.
Race Director
Joined: Sep 2003
Posts: 13,550
Likes: 6
From: Now in God's Country, the Big Sky, Montana!
Cruise-In 7-8-9-10 Veteran
St. Jude Donor '06-'07-'08-'09-'10-'11-'12
Originally Posted by zulatr
who or what is catek?
Melting Slicks
Joined: Feb 2005
Posts: 2,087
Likes: 4
From: granville mass
Originally Posted by Cobra4B
Yes, I actually installed a brand new LUK Stage-II assembly that was guaranteed to be zero'd out. Then I got a rather annoying vibration. That clutch eventually broke and my rear main seal started leaking.
The Corvette tech mis read the LUK instructions ( you have to torque the pressure plate to the aluminum flywheel at a lower torque b/c the alum is softer) he torqued the flywheel to the crank at the lower settings and the bolts sheared off.
Fun ****.
I sent the shop that's been doing my engine work for years this thread, and they picked up on this statement above. His thought was that if the bolts were never torqued properly, you couldn't be sure what was causing your vibration, and that if the assy was properly torqued, you may not have had a problem. When I asked about your 8 gram out of balance that you measured, and re-introduced, he just said he's never heard of anything like that, and 8 gm is a mile off.
I'm getting cold feet on the aluminum flywheel install I wanted to do because now I'm going to be hanging the car up on a lift while the parts are in the machine shop to be checked. That just will not cut it the way I get my stuff done.
Thread Starter
Instructor
Joined: Sep 2001
Posts: 119
Likes: 0
From: Evansville IN
I called several machine shops, there were several that had absolutly no idea what I was talking about. I finally found a shop locally that balances race engines and they said no problem. I guess it takes a special type of machine such as a "Hines" or "Stewart Warner" balancer.
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Team Owner
Joined: Mar 2001
Posts: 25,889
Likes: 7
From: Virginia Beach
CI 3-5-6-7-8 Veteran
Look... I literally poured over the forums after getting into this issue. I called 21st century, A&A, Lingenfelter, MTI, ECS, and Cartek to talk to all the top of the line Vette tuners. All said that it can be a problem w/ LSX motors. They said that most are fine, but some can and do need a match balanced clutch. Seeing as how there's so much labor involved in the process I'd want to make sure mine's right.
Step 1 take stock clutch assembly to machine shop and have it spun up. If it spins out balanced then yuo're fine. But if not then you know it's off to compensate for the motor. It's really very simple.
I know for a fact that my stock clutch ended up being 8grams off and now after matching it the car is like stock again.
Talking to the tuners they always balance a clutch even when new b/c they're not always zero'd eventhough the mfgs say they're supposed to be. Some are as much as 40 grams out. This is comming from lingenfelter.
Step 1 take stock clutch assembly to machine shop and have it spun up. If it spins out balanced then yuo're fine. But if not then you know it's off to compensate for the motor. It's really very simple.
I know for a fact that my stock clutch ended up being 8grams off and now after matching it the car is like stock again.
Talking to the tuners they always balance a clutch even when new b/c they're not always zero'd eventhough the mfgs say they're supposed to be. Some are as much as 40 grams out. This is comming from lingenfelter.
Melting Slicks
Joined: Feb 2005
Posts: 2,087
Likes: 4
From: granville mass
thanks for all your help and insight.
now it will be a matter of being able to tie a lift up while the original flywheel and clutch are at the machine shop - as Cobra points out, this isn't where you want to make a mistake. It sure makes the whole process a pain that this isn't a car that you can roll off the lift once you've started the job....
now it will be a matter of being able to tie a lift up while the original flywheel and clutch are at the machine shop - as Cobra points out, this isn't where you want to make a mistake. It sure makes the whole process a pain that this isn't a car that you can roll off the lift once you've started the job....
