Flywheel step

[prove_it]

I'm going to be switching to a ACT 2600 plate and a OEM disc. I know that .610" step is what is recommended, but is this number right for every disc/flywheel/plate combo?


Yes, yes, odd combo, blah blah blah. I have the plate leftover, got the disc for 80, and have a ACT streetlight flywheel already. I'm doing this as a budget clutch to hold 350whp with great DD ability.

In time the OEM will swap out for a SB puck disc.

 

[gaylantvr4]

Jon from tre recommends a.607 step

 

[gaylantvr4]

If the car is a dd I would stick with the stock flywheel. I have never been a fan of the lightened flywheel. The drivableity will be much nicer.

 

[prove_it]

I've had the streetlight installed with a 2100 ACT clutch for 5 years....

At 320 she's finally slipped on me. This thread isn't about recommendations for set-up, more a tech discussion on proper step on the flywheel.

 

[gaylantvr4]

witch, I gave you on my first post

 

[manikbastrd]

I went with a thousandth under the minimum reccomended. I have a comp stage 3, and it works well. The step height is all about correct flywheel height in order to get a full disengagement of the friction disc. Every clutch will be slightly different, but I think that my engagement has gotten better over time rather than worse. Just my .02 if it helps

 

[slugsgomoo]

I believe the vfaq has RRE's recommendation, I want to say it's .609 though I'm guessing Jon at TRE wouldn't be a bad source either.

For what it's worth I've daily driven a car with a fidanza (noticeably lighter than the ACT) for a long time and there are no drivability issues. You want to talk about those let me tell you about the flywheel weight of my PTT setup... /ubbthreads/images/graemlins/wink.gif

 

[belize1334]

Spec is 0.608 - 0.612. That's true of any OE replacement clutch, regardless of mix / match options. Anything in that range will be fine. Ask the shop for 0.610 and you're not gonna have any issues.

 

[Wizardawd]

Only time that number would change would be if the disc would be of a different thickness. And to my knowledge, none of them are different. And Ryan, I have run the OEM disc's on my current 2100 setup, and many 2600 setups in the past with actually better results than the ACT disc. Not to mention, cheaper and available locally. So I approve this message.

Wiz

 

[prove_it]

That's what my research has been showing me too. I got the mitsu disc for 90 bucks new. Can't beat that.

 

[tektic]

I'm thinking for my south bend clutch I'm going to need a higher step.

In this thread they are going to .620

click

How did you make out with yours?

 

[AllanL]

this was my email from TimZ late 2013.

clutch/pp combination was the SS-TZ with the stcok flywheel


No problem, get it resurfaced to a 0.612" flywheel step height.

If your machinist requires new dowels, they are M8x18mm otherwise the OEM Mitsubishi number is MF472404, and you would require 3 new ones. Be sure they machine it perfectly flat across the entire plane as if you do not do it perfectly flat the Kevlar lining will not bed properly and will have uneven wear and decreased torque capacity. As well, after It is machined, have it media blasted with 80/120 grit aluminum oxide blast media to increase the surface porosity as Kevlar material beds in faster and better with a porous surface in comparison to a smooth machined surface. Kevlar works best against a surface that can bond in Kevlar and have a Kevlar to Kevlar (or steel with Kevlar particles bonded into it) bedding surface for best longevity, torque capacity and heat dissipation. The biggest benefit is that if you launch the car on a media blasted surface flywheel with a properly broken in Kevlar clutch, you will have a significantly lower chance of slipping out and glazing the clutch in comparison to a flywheel that is not media blasted. This is because a flywheel that is simply machined flat and smooth cannot bed any Kevlar into the pore surface and when you slip the clutch hard it will simply wipe the surface clean and it will result in the Kevlar material glazing and heating up causing slippage. You would then need to let the clutch cool down and drive it normally for a while to properly break the clutch back in. it won't be trashed but you need to break the clutch back in just like a brand new clutch with zero mileage.

The pressure plate will already be media blasted per my specifications from SBC so you won't need to do anything to the clutch or flywheel itself. If you are not able to do these services to your flywheel, at least get it machined flat and to the 0.612" step height and then run a Kevlar / Ceramic TZ/B clutch disk as it will eliminate the need to media blast the flywheel with an aluminum oxide blast media. Ceramic doesn't require the media blasting process to be optimized for break in and racing; it beds in just fine on a machined smooth surface.

 

[prove_it]

Quoting tektic:
I'm thinking for my south bend clutch I'm going to need a higher step.

In this thread they are going to .620

click

How did you make out with yours?




Haven't been able to run it yet. Shortly after I started this thread, my trans completely grenaded. Been sitting in the drive ever since. It will be months before I do anything yet.

 

[GSTwithPSI]

Trans grenaded? What happened?

 

[prove_it]

Well.... I was screwing around in 3rd at about and thought I'd open it up, well I roll into the throttle at 3700rpm and start going, the cyclone opened up and I heard a huge, and I mean huge, boom!!!. Next thing I know I'm coasted with a noise that sounded like a bunch of screws in a blender at full speed.

Coast to a stop and try to creep in first and it would bog down and struggle to move. Had Mike come out and tow it with his lancer. He said he had to go full throttle in 2nd to pull it at 15mph. It does not move much. Not sure what popped, but it was epic.

Really suprised that this was in 3rd gear, but I think what happened is I got into it just right so I had a 28psi hit and cyclone engaged all at once which shocked the crap out of the trans. Pretty sure it was the center diff. I've been having issues with launches just before that. I'd drop the clutch and the front wheels would spin like crazy for about 3 secs, then it would start pulling.

Stock 93 dsm trans.... Number 6 now. /ubbthreads/images/graemlins/rofl.gif So now I'm saving up and rebuilding it with parts from my two blown trans in the garage, with all new bearings and an EVO gearset. Soo, now it will have a fresh trans AND clutch. Hoping to run deep 11's next summer now that I have Nitrous to throw on top of it too.

 

[GSTwithPSI]

I'll bet you cleaned all the teeth off of 3rd gear. It's always the weak link when you start making any sort of power. It would be surprising if you trashed the diff from a roll.

 

[prove_it]

I'm only hitting 320whp peak, lol. At 4k it must have been the torque, but even then it's not that much. Damn weak gears. One day I'll open it up. I'll post pics. All I want for xmas is a shep stage 4 trans....

Doubt I'll wake up to that under the tree though.

 

[GSTwithPSI]

I've been strongly considering a set of face plated gears from Liberty Transmissions. I have a spare trans I can tear down and pull the cluster out of to send off to them. I just wish I knew more about them. Seems to me when it's all said and done, you have a sudo-dogbox. Still the same weak ass gears, but at least it would shift at 10k. I think blackvr4 is running a set in his car.

 

[prove_it]

Sad part is that I have never wanted to make 500hp due to not wanting to deal with dead trans all the time, yet I've killed 6 now at under 400whp.
Cracked a bell housing. (my bad for leaving the rear bolt out)
Distroyed 1st &2nd syncros, which took out all bearings
Blew up a 1st gear(gvr4 1st).... twice
Blew a input shaft bearing which allowed the shaft to eat into the sandwich plate of the housing
And now this one, yet to be determined

Oh well, love the car too much to build something else. That's why I recommended an auto for reliability in a separate thread. /ubbthreads/images/graemlins/rofl.gif

 

[tektic]

Wow, That's a lot of trans carnage. The cyclone does hit pretty hard in my car too.

I'm going to try to have my flywheel stepped a little extra. I'll let you know how it comes out.