Flywheel re-surfacing for Kevlar clutch

[The S is Silent]

Chris,

I just got my flywheel back from the machine shop...and I'm not sure it's going to fly with the kevlar, but wanted to run it by you first. Here are the pics. You can still see the machining lines, and you can feel small ridges...like it's not completely smooth.

http://people.clemson.edu/~mkessin/Pictures/Charger%20Pics/Flywheel%20far.jpg

http://people.clemson.edu/~mkessin/Pictures/Charger%20Pics/Flywheel.jpg

Do I need to try and get it smoother? Would a new flywheel from ma mopar have the correct finish? Would a new aluminum flywheel have a smooth enough surface?

[Turbodave]

Not sure about the Kevlar clutch disc, but everytime I've ever had a flywheel cut they looked like that, never had a problem with them on a normal clutch disc.

[BadAssPerformance]

Looks like most I've ever seen machined. I've never had a ceramic clutch, but with a puck-type sintered bronze clutch, one trip around the block and it will be smooth where the clutch goes :thumb:

[The S is Silent]

Chris told me that the contact surface between the clutch face and the flywheel needs to be as smooth as possible or else the kevlar will wear faster. This doesn't appear to be that good. I'd be fine for a normal clutch, but I was thinking something closer to rediculously smooth for the kevlar clutch. That finish was as good as the machine shop I went to could do.

[BadAssPerformance]

Some machine shops are smoother than others, it all depends on speeds and feeds and tool sharpness.

Wow, I didnt know Kevlar is that soft. I ran a Kevlear fiber re-inforced RPS clutch for years w/o issue.

Chris, any words for the whole class here?

[Chris W]

Sorry, I just spotted the thread a few minutes ago.

In any case, you need a stone ground surface. It needs to be as smooth as the pressure plate contact surface. That means you should be able to run your fingernail across it without it catching on anything. That flywheel would be okay with a ceramic or organic clutch but the kevlar will not survive. Did you get the instructions on flywheel surfacing with the kevlar?

Chris-TU

[mcsvt]

I wish I had known this earlier. Luckily mine hasn't gone in yet. And all I got in the box with the clutch and pressure plate were warning messages about shattering discs or something.

[The S is Silent]

Did you get the instructions on flywheel surfacing with the kevlar?

Nope. It came with a warning about high torque, high RPM usage, and a little sticker that says that flywheel surface has to be crack free.

I'm going to run it by the machine shop here on campus and see if they can't do it for me. I'm not really in trouble with this...I have a few more options, but I don't want to pay $25 each time to find out it's not a satisfactory surface.

Chris, what about a new flywheel or a lightweight one?

[Chris W]

Nope. It came with a warning about high torque, high RPM usage, and a little sticker that says that flywheel surface has to be crack free.

I'm going to run it by the machine shop here on campus and see if they can't do it for me. I'm not really in trouble with this...I have a few more options, but I don't want to pay $25 each time to find out it's not a satisfactory surface.

Chris, what about a new flywheel or a lightweight one?

It all depends on who is doing the machining and how much time they spend on them. The flywheel surface MUST be as smooth as the pressure plate surface. I checked with my manufacturer and he will be including the above underlined statement with all future Kevlar clutch packages. We also added it to our description of the product.

Chris-TU

[The S is Silent]

It all depends on who is doing the machining and how much time they spend on them. The flywheel surface MUST be as smooth as the pressure plate surface. I checked with my manufacturer and he will be including the above underlined statement with all future Kevlar clutch packages. We also added it to our description of the product.

Chris-TU

I got it taken care of. Is mirror finish good enough? :eyebrows:

[mcsvt]

Now I am going to have to check my flywheel when I get home :(
I have no idea of any shops in this area. If i was still in school I would do it myself, but I don't have access to that shop anymore.

Guess it is time to break out the phone book...

[The S is Silent]

The machine shop here does it for $30...but I don't think it would be cost effective to ship it here and have me ship it back. Those things are heavy. Although it would probably cost less than taking it somewhere and paying them $24 dollars just to find out that the smoothest they can do is no good enough. :banghead:

[mcsvt]

LOL yeah I know what you mean. It is a "lightened" flywheel though...

I still have to look at it when I get home, can't remember what kind of finish is on it. I will have to specify how smooth I need it when I start looking for a shop.

[The S is Silent]

LOL yeah I know what you mean. It is a "lightened" flywheel though...

I still have to look at it when I get home, can't remember what kind of finish is on it. I will have to specify how smooth I need it when I start looking for a shop.

Oh...in that case, how about I send you mine and you send me yours. We'll trade :thumb:

And because yours is lightened...you'll have to pay less shipping than me. :D

On a serious not...how lightened is yours? How did you do it?

[mcsvt]

I bought it from a board member. He had his machine shop do the lightening. Seems like they took some meat from the back side of it so the face is still solid. Not sure on weight, I will check tonight when I look at the finish. I'll probably take a pic as well.

[The S is Silent]

Awesome, I'd like to see that. I might have mine back tonight as well. We'll see how much the stocker weighs.

[mcsvt]

Here are some pics of mine.

Weight: Looks about 14.5-15lbs
http://www.turbo-mopar.com/forums/photopost/data/500/medium/flywheel-weight.JPG

2 pics of the back:
http://www.turbo-mopar.com/forums/photopost/data/500/medium/flywheel-backside2.JPG

http://www.turbo-mopar.com/forums/photopost/data/500/medium/flywheel-backside1.JPG

I checked the finish. I looks like yours at the top :(. Going to start the machine shop search now.

[BadAssPerformance]

I got it taken care of. Is mirror finish good enough? :eyebrows:

Pics? Mirror? I thought they wanted a little non-directional cross-hatch like the p-plates have?

[The S is Silent]

I havn't picked it up yet. I'll post pics tomorrow. I'm sure it will have some marks, but it should be really close to the pressure plate.

[The S is Silent]

Got the flywheel today and I'm very happy with it. Much better than the last one.

http://people.clemson.edu/~mkessin/Pictures/Charger%20Pics/Flywheel%20Good.jpg

There is some fuz on it, but I'll brake kleen it before I install. I also weighed it, and it was 17.5 lbs.

[mcsvt]

Looks great. Still haven't found a place to do mine yet. Kinda got distracted by work ;)

[2.216VTurbo]

Just picked up my flywheel from the machine shop-the only one in town that has a flywheel 'machine' (most are still cutting them on a brake lathe type machine-not so good for flatness!) Since this thread was going I asked him about the RA finish. Seeing as how I had to explain it to him what an RA is and that certain clutch manufacturers had an RA spec requirement, he was pretty much no help in determining what the RA of my finished flywheel was:o

No, I am not running Kevlar-been there done that. Kevlar has a much lower coefficient of friction than organic or sintered (it's 'slicker') so to make one work properly you need a boatload of clamping force. I am getting too old for DD type set ups.:yuck: My experience with the duals is like ten years old so no doubt, technology has moved on. I think I read somewhere that spec has altered the pivot points on the diaphragms to increase clamping force rather than running a super heavy cover.

[Chris W]

I think I read somewhere that spec has altered the pivot points on the diaphragms to increase clamping force rather than running a super heavy cover.

The pivot points are altered on all our High End clutches as well. This provides much higher clamping forces while retaining the stock pedal feel.

Here's some feedback from one of our customers:

http://www.turbo-mopar.com/forums/showthread.php?t=4060

Chris-TU

[packrat_turbo]

I know this is an old thread but I just wanted to comment on whether you need a mirror finish on a kevlar flywheel. I got a kevlar clutch with pressure plate through turbosunleashed and I dont think the pressure plate is a mirror finish . Dont you just want to have the flywheel ground like the pressure plate? It is smooth but I dont think mine looks mirror smooth. There can be quite a difference between not catching your fingernail and mirror smooth.I had mine done at Scottsdale automotive machine, which Dave said they used a stone ground type method.

Tom

[Chris W]

I know this is an old thread but I just wanted to comment on whether you need a mirror finish on a kevlar flywheel. I got a kevlar clutch with pressure plate through turbosunleashed and I dont think the pressure plate is a mirror finish . Dont you just want to have the flywheel ground like the pressure plate? It is smooth but I dont think mine looks mirror smooth. There can be quite a difference between not catching your fingernail and mirror smooth.I had mine done at Scottsdale automotive machine, which Dave said they used a stone ground type method.

Tom

Stone ground with a surface equivalent to the pressure plate surface is all that is required.

Chris-TU