Thinking about switching back to an act puck disk after the last trackday
 

I bought the FM stage one happy meal last year and have really enjoyed it so far, the drive-ability is great. But on the way home from a track day at the local road course yesterday the clutch started slipping. I'm thinking the organic disk just can't handle the heat and it's probably time to go back to a 6 puck act.

The car is a 1.6 with forged bottom end running 16psi on what once was a greddy(td04h 15g) kit, 225 nt01 tires and some aero. The car sees mixed track and street driving, and has less than 5000 miles on the clutch.

Anyone see any problem with using an act sprung 6 or 4 puck disk with the rest of the FM happy meal combo?

You probably should have gone with the S2.

I don't like the engagement on the Spec S3 clutch because its hard on drivetrain parts, but it never slips and never overheats. I'm saving up for a twin disc for my next clutch.

I don't have any dyno charts, but I didn't think I was near the torque limit of the stage one. It hasn't ever slipped on the street, or on the track with street tires. Just started with the nittos and minor aero. Anyone with a S2 living at the track with a similar or more aggressive setup?

I avoid spec clutches, had a few stage 3's melt to the pressure plate with the old 240.


I'd love the twin disk setup, but not at twin disk prices.

Have you called FM and talked to them about it? I have the FM2 and will be very upset if it start slipping when I start the track the car next spring.

Did you have the flywheel turned when you installed it? My ACT performance disc didn't hold up at my recent track event. i think it is because i didn't have the flywheel turned. Either that or the 12% estimated drivetrain loss is underestimated, and I've heard the ACT clutches are conservative with their ratings. Mine should have held 302 at flywheel, and I put down 255 at wheels recently. I ordered an ACT 6 sprung 6 puck. It hasn't been installed yet.

Yea, Brandon at FM brought up a very good point that it may be a hydraulic issue.

It makes sense that the fluid might be getting hot to the point of boiling (or that I had a preexisting air bubble), and expanding, the piston in the slave putting pressure on the fork. The hood I was using wasn't vented near the turbo like my other hood is. It didn't slip at the track, but on the way home after my last session, I didn't give the engine bay much time to cool so it might have gotten heat soaked.


I haven't driven the car since I got it home, I'll replace the fluid and do a through bleeding.


The flywheel was brand new when installed, it was a full fm happy meal kit.

I think you were right in your first post. I have a FM stage 2 clutch in my 94 1.8l on 10psi. It seemed to hold the power just fine. Wouldn't slip at all, but couldn't take heat. I was at the drag strip and I would make a run and let it cool. Sometimes I let it cool 20-30 minutes and when I made another run it would slip. I doubt my fluid was getting that hot it started boiling in one run in the 1/8th mile, then cooling, the another 1/8th mile run. In my opinion the FM just can't take the heat were throwing at it.

I'm also looking at going to an ACT 4 or 6 puck clutch.

The jury is still out, I've got a few more things I want to try before I give up on this clutch.

I too am on a FM S1 and it doesn't like repeated abuse. This is also the only clutch that I've driven that even thinking of hovering over the pedal and it will slip. Yes I have proper free play. I'm thinking I have some kind actuation problem but I'm not certain. Does yours take the FULL pedal travel to disengage and the very last bit up top to engage? I've got it adjusted as far out as possible and still have proper free play. It's annoying to drive and doesn't seem to hold the torque its rated for.

free play is a function of the upper clutch switch. you want free play...too little and when the fluid expands in the heat is no good.

I dont see how these could just suddenly not hold abuse. clutches are pretty simple, so unless theres really an issue with the PP not holding down hard enough, or the clutch disc itself slipping, it could easily be an issue with hydraulics preloading the diaphragm.

Ive driven on the FM1 ona car making over 275rwhp...we've abused it and autoxed it...no issues.

My upper switch is adjusted basically all the way out and the actuation rod is adjusted as long as possible while still having freeplay to get the disengagement point higher. It still takes practically forcing it to the floor to disengage enough to get into reverse. I let up a little I can hear the tranny start spinning. And it wont fully engage unless it ALL the way up, any little pressure on the pedal and it will slip. I've bled the system a few times with no change. My "butter zone" still includes the whole travel. Slave is a few months old and had the same problem with the old one. Replaced this one do to the old one leaking. I'm at a loss.

Ok after venting the hood over the turbo, adjusting freeplay in the clutch, bleeding and re-bleeding, and upgrading the fluid. The clutch didn't slip last weekend. I'll update if it starts slipping again.

Would you mind going over your adjustment technique, and new fluid you are using? My car is in the shop now having the 6 puck and replacement 6 speed installed. My disc looked like ass. Glazed really bad. My mechanic said the flywheel was in pretty bad looking shape before he sent it of to be turned. I suspect that this situation would have been avoidable if I had turned the flywheel to begin with. That being said, I was not about to risk it happening again with the organic disc, so I went to the 6 puck.

Just got my car back today with the ACT 6 puck installed. It's great! It has almost the same feel as the performance organic disk. It grabs slightly quicker, but it's by no means harsh. It's fine.

Anyone interested in a 6 puck should know that I did not swap from a stock clutch. I have no comparison. I went from and upgraded eedy to the ACT xtreme with organic disk and pedal effort was a lot more, and engagement was much more harsh (quick, no slip).

The jump for xtreme pp and organic disc to xtreme with 6 puck is barely noticeable. I actually like the crispness that it engages.

Having gone through a few stock clutchs, an act xtreme, and an act sprung 6 puck, I'd say they're all fairly different.

The stock clutch assembly feels like a feather for pedal pressure.

Xtreme is sorta like stock but with a nice heavy pedal

6 puck is sorta like Xtreme but you have to slip it more at low speeds. If I was going to stay under 300 i definetly would go with a act xtreme.

It's an ACT xtreme pp with a 6 puck sprung clutch.

Update:

I can see how people who have to deal with stop and go traffic would not want a 6 puck. I generally don't have to deal with this type of traffic, but experienced it a couple days ago. When trying to SLOWLY creep forward with this style clutch it gets to a point where it starts to shudder. I guess this is the point when the clutch really isn't slipping anymore.

If you live somewhere that stop and go traffic is pretty none-existent, then 6 puck is just fine. I like it. If stop and go traffic is a regular part of your commute, then it would get old pretty quick.

Motul RBF600, the adjustment is under the dash on the linkage between the pedal and the master. You need to stick your head in the footwell and look up, take a flashlight(or fleshlight if you're into that kind of thing). There is a threaded rod with a nut that tightens into the clutch pedal. I bled it really well to get the air out, then adjusted the pedal linkage.

To be honest it did slip on the highway on the way to the track, but I think it just had a gaze to it at first from the last track day. It didn't slip again all day.

I typically use unsprung puck disks, I've broken the springs out of other sprung clutches, but the puck disks are a lot harder on the rest of the drivetrain. I really like the driving manners of the FM clutch, hopefully it will save a transmission or two.

It all depends on the wheels tires and break upgrades you have. An r compound tire soaks up tons of power on a dyno, i have seen a 40hp increase to the wheels switching from et street slicks to nitto invo street tires. have also put an additional 10psi in the rear tires of a mustang on mt drag radials and watched it pick up 20whp. also if you have some enormous breaks those are gonna soak up alot more then the stockers would, obviously. you are talking about torque right? you must be making ungody power numbers.

Another thing you can do to help the clutch heat issue is drill the bellhousing vent out a little bit. If you use a 1/2" bit to open up the hole at the bottom of the bellhousing it helps cool the disk faster.

Just a simple/free potential solution

This doesn't sound like a good idea. And wouldn't you want to do it on the top since heat rises?

Theres an existing OEM hole there already, just use that as a pilot.

It works to some degree otherwise i wouldn't suggest it

Well it looks like it starts slipping towards the end of the day still. :\

I'll have to add a clutch job to the growing list of projects on the table.

Anyone have a recommendation on which 4/6 puck to get and cheapest source? I would like to reuse the FM pressure plate.

I'll probably get an act 6 puck unsprung through summit if no one has any opinions.




I'd love the 949 one, but I'm not going to spend 1k+ on the clutch.

Carolina Clutch? I got my sprung ACT 6puck from there.
http://www.carolinaclutch.com

I think y8s recommended them and the guy was nice and well priced and shipped fast.

+1 Great price and fast shipping ACT 6-puck, XT pp feels great. I adjusted the pedal using the FM guidelines.

After driving them both on the track I prefer the feel of a pucked clutch for track use. They are a little difficult in 1st and R if your not paying attention but easily overcomed if your a man. I do agree that they are harder on the drivetrain but if you use a little mechanical empithy it shouldn't be a problem. For quick snap shifts a 9lbs fly wheel from gripforce let the revs drop fast enough that it didn't feel like I was shocking the trans.

So did you eventually get the Xtreme 6 puck sprung clutch or the Heavy Duty?

I read and looked up some prices. Don't mind the universal pictures but the serial numbers check out.

almost 50 bucks cheaper compared to Gomiata same serial number

http://www.carolinaclutch.com/ShowIt...tch%20Kit.aspx

http://www.gomiata.com/actmi6padrac1.html

Xtreme ACT clutch 6 puck sprung picture not shown but serial number clears


Cheap
http://www.autopartsdealer.com/act_x..._content=rank1

http://www.jdmhub.com/index.php?rout...1131_1132_1443

Clutch and flywheel.

+1. An extra $300 to shave fourteen pounds of rotating mass from the drivetrain sounds like money well spent to me.

By the time you put together a clutch disc, plate, flywheel, and throw-out, you're $200-300 away from video-game style driving glory. People that haven't driven it, don't understand...it rev's like a damn SR-3. I finally drove John's car on the track with the clutch and I grinned the entire time. My tax return is supposed to go on student loans..right? God damn you 949 Racing.

I remember grabbing John's single disc and comparing it to the one that came out of his car, and the suspended disbelief that followed.

Why is it ok to take mass off the rear of the crankshaft but not the front via a lightweight pully?

Is there some "happy rotating mass on the end of the crankshaft threshold"??

How much does the pulley on the front weigh?

Less than 9lbs or whatever a lightweight flywheel weighs. 3lbs?

I'll sell my old twin plate setup to you cheap. needs new disks and floaters. total weight is like 16 lbs including the flywheel.

Because the pulley dampens vibration and a single-mass flywheel (basically) doesn't. It's fine to put a lightweight pulley on, as long as it sufficiently dampens the vibration coming from the motor. It's not the weight loss that causes issues from LW pulleys, it's the fact that you've removed the harmonic damper.

So. Why not have a dampened flywheel?

I mean, other than material/construction issues, this would be great right?

How much do you think that would weigh?

I'll give you a hint: The 4th gen Toyota Supra has a dual-mass dampened flywheel (the Getrag is really noisy without it, apparently). It weighs 34lbs.

LG takes the stock 63lb ZR1 clutch down to 18lb.

From what I'm thinking it would be an extra $800+ unless someone bought my current flywheel, pp, and disk for a premium.


I'd love the 949 setup, and I know it's the best way to go. At this point I'd rather get something at a lower cost that works, and spend that cash on lower hanging fruit like an OS Giken diff, or real shocks/springs.

You want to sell the twin disk? How come? I might be interested but I just want to hear from you your pros and cons about it.

Was that addressed to me?

While it works very well for a street car, it's just not up to a 20 mile commute with stop and go traffic. Service life in real-world daily driver use is between 18 and 24 months. The reason is slippage and heat. The parts dont wear out, they warp over time.

In a track/race car, the clutch has a much lower slip-to-rest ratio and it gets time to cool down. And the number of times you are starting from a stop when racing is pretty low compared to in traffic.

I suppose I could have vented my bell housing (and now that I think about it, I wish I had tried that) to get more life but I didn't.

Pros: bragging rights, holding nearly 400hp, near stock pedal feel, easy driveability.

Cons: I don't have a garage anymore so changing it every 2 years gets to be a bit of a challenge (especially since my driveway is dirt). That's really it.

Thanks for the input. I do have a dd and though I don't see much stop and go, the idea to fix and swap parts every couple years is a turn off like you said. I will be autocrossing on weekends whenever there is a track setup locally. I also do not own a garage and see why it's an inconvenience. I did plan on getting a street clutch and lightened flywheel what rounded around 800 and thought that if I saved an extra couple hundred for the twin disk. But after your experience I appreciate you solidifying my decision.

Note that Y8s is a home built twin based on Tilton hardware and using I believe, .150" thick discs. The 949 Racing twin is not a Tilton and uses custom made .250 thick disc (same thickness as OEM). Our twin organic will last a very long time, probably forever for most users.

i have the rally clutch which uses .280 thick disks. as i said, they didn't wear out, the floaters warped.

Everything was dry inside and did not see any signs of contamination. but I did see lots of evidence of over heating and slipping.

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I switched back to a 4 puck and seems to be good, but haven't had a good chance to thrash it at the track yet.

With localized heat spots on the pressure plate and I think the friction plate, I would suspect something is/was bent or is/was mounted incorrectly (not flat).

I torqued to the proper torque, using the proper method. But that could have been a possibility. The other side of the disk does not have that same pattern. You can see the discolorations on the disk from heat.

I just bought a spec 3 clutch with a fidanza flywheel. Its going in the beginning of next week. I also purchased ss clutch race lines from 949 today. All I need to do is buy replacement seals and such for the rest of the job.

only looks like half the material was grabbing.

My Exedy Stage 1 started slipping after slightly less than 12 months of use. Yesterday I ordered the ACT XT/6 puck sprung setup to replace it. I've never had a puck style disc before so its going to be interesting to try it out.

If your not paying attention, it will make you look like a kid that is just learning to drive a stick when pulling away from a stop light.

You'll quickly get used to it. But it takes me care when starting from a stop like djp suggests. I could drive mine like a stock disc, but I got tired of the effort required when DDing the car, so I went back to a street disc.

Thanks for the input guys. The only time I usually have serious stop and go traffic is coming home when I'm working 7-3:30 on a weekday which is usually only 6-8 times per month.

I like mine a lot