Hey guys, been searching like crazy and can't seem to find if there is an ACTUAL minimum flywheel thickness for the Stock flywheel since Mitsu only reccomends replacing it and not servicing it? Anyone know this spec if it exists???

 

The stock flywheel cambers inward towards the center, also, if you have to cut it to get it smooth the balance will be offest requiring a rebalance as well. Even if the flywheel gets step surfaced and rebalanced the pedal will be offset too

 

Well, plenty of members have resurfaced the stock flywheels without an balance issues as far as harmonic vibrations are concerned at least. What exactly do you mean by the pedal being offset?? It is adjustable to compensate after all.

 

The pedal will engage higher off the floor so you will have to adjust it closer to the floor thereby narrowing the pedals range of movement alltogether.

The reason for this is the pressure plate, with the flywheel cut flat, will be moved at least 1mm inboard, this change in turn is felt through the whole assy (bearing, fork, pushrod, ect), and more prominant at the pedal.

I learned this the hard way, lukily I have a spare unalterated used 40K flywheel laying around. This time I resurfaced the face by hand and sent it off to a machinist to get rebalanced to at least 1 gram. The stock step inwards is still intact.

One thing, to get it rebalanced they might have to enlarge the center disc guide hole to 1.5" to fit the standard guide on the machine

 

1mm!?? Jesus, what'd you do to that poor flywheel? Thats .040", I resurfaced mine at .010" and I felt that was a lot, most are smoothed at around .005" to clean them up and remove any warping. I'm not concerned, especially since so many have done it before me. Next clutch will have a new flywheel.

 

With a straightedge over the face of a mits flywheel there is about a 1mm (approximate) camber towards the center. To get it cut flat the same amount will be removed at the edge. My first clutch r/r the flywheel was cut, my next r/r (soon) I just smoothed it by hand and the machinist is balancing it now.

 

I don't see how or why this is possible. The stock disc isn't angled to wear evenly on such a surface and a cast steel flywheel isn't going to flex .040" under the clamping force of a stock clutch. My flywheel came out for the first time and had LESS than .005" warpage across the ENTIRE flywheel. I work at a machine shop running vertical drilling machines and had the CNC lathe department chuck up my flywheel in the most accurate machine we have (can hold a 0.0001" tolerance) which costs nearly a $900,000. The first pass was .002" to knock down the high spots from the warpage. Next we took another .003" to clean up the surface all the way across. If what you're saying is true, we'd have only made contact on the outer edges and wouldn't have cleaned the surface all the way across.

We then machined another .005" to get past some hard spots on the surface from the clutch slipping. After all was said and done, it was measured and had +/- 0.0002 of taper across the entire flywheel. Definitely overkill for a flywheel but the machine just kicks butt,lol.

 

Did you ever find an answer to the original question in the first post?

Thanks!

 

I didn't, but I have had zero problems with my clutch/resurfaced flywheel. Just dyno'd over 300whp at Buschurs and made a handful of 1/4 mile passes at the dsm/Evo Shootout without any incident.