Adjust the clutch?

I don't know how aggressive you've got yours, but I've redid mine a little looser to alleviate occasional hard shifts. Feels like the clutch hasn't let go entirely as you shove the shifter out into neutral, makes a nice loud bang. Most times I'd even hit the next gear still, like I was so close to the disengagement point that the little tiny bit of torque I had going on was enough to keep things in contact.

I'm not stupid and I know I've got my foot hard on the floor, but it would still only happen occasionally and not since I've made it a bit looser. Maybe you're out there heating up and growing the disc material or something, more room might help?

Isnt there an issue that people often run into with FM clutches about having it adjusted wrong that causes no disengage when hot because of a bleed port or something?

I think it could be the clutch adjustment. I can't even remember where it grabs, going to check that out today and probably adjust it.


Also you mention growing the disk. I'm launching the thing at 5,100 in boost, and slipping the clutch for about 10' out of the hole (so about 1/4 second) but I know that's throwing a ton of heat into it. Was cutting 1.76 60' times doing that. Someone at the track mentioned it getting to hot and the disk growing, so yeah maybe that's it.

But if it is, how do I fix that? Adjust the clutch so it disengages so much that it still disengages when super hot?

Leafy, I've never heard of that, but if you got any more info I'm all ears. I have an ACT Extreme clutch, but maybe I'm having a similar problem.

Ok so I just went and checked the clutch pedal out. As it was, it starts to grab a tiny bit about 1/2" off the floor. That is, I can feel the syncro's having to do work to get it to snap into gear after the pedal was 1/2" to 1" off the floor. But it didn't really grab until 2-3" off the floor.

I adjusted it about as much as possible. My adjuster rod is barely threaded all the way into the nut. Now it's about 1/2 way threaded into the nut, so can't really adjust it out much any more. I also adjusted the upper clutch switch out a touch so the pedal will come up a bit more so I'm not keeping pressure on the throw out bearing when the pedal is out.

This changed the pedal engagement for the better. Will have to run it at the drag strip to see if it's better or fixed. But I'm not sure if this is normal, seems odd. I hate to think my 8yr-old-bought-used ACT Xtreme could be compromised???

From looking at what it's doing, it seems a larger bore master cylinder for the clutch system would help, since that would move the slave cylinder more for the given clutch pedal movement. Or maybe a different clutch line to replace the rubber one, perhaps it's flexing and soaking up some of the travel by stretching the hose.

You still have that nasty rubber clutch and pigtail line?

Bees knees is the 1 piece stainless line, or the short stainless stub line like I've got.

I bet what little extra throw you added in the pushrod will keep the clutch further enough out when hot now, though. I went the opposite direction with the clutch switch, but I'm pretty sure it's not engaging the master at all, I can feel a bit of slack between the pushrod and piston at least.

What clutch line do you have? I'm going to order one, it can only help.

I have this, it uses the firewall hardline still but ditches the pigtail and rubber.

Miata MX5 clutch line

There's a longer one piece deal that replaces the hardline, straight shot from master to slave.

MiataRoadster "Straight Shot" clutch lines MAZDA - MiataRoadster - High-performance customer service...and parts for Roadsters

There may be other places to grab both these.

Let me know what you find out...

I replaced the entire clutch hydraulic system two months ago, brand new master cylinder, slave, ss line all from FM, amsoil brake fluid, flushed it many times...

2500 miles later the fluid is black again. And the clutch pedal moans sometimes when its pushed in/coming out...

I ordered a stainless line to replace the stock rubber one, and a bronze shifter bushing and something else. I doubt that fixes anything but we'll see. I'm actually beginning to wonder if maybe the clutch is worn enough that the angle of the lever that actuates the PP to disengage is affecting how much "throw" it moves, causing it to not fully disengage. No idea, will have to climb under car to look, but that's a possible explanation I came up with.

If the clutch line doesn't fix it, I'm going to look into modding the pedal to gain a bit more travel.

Hm, that could be an explination for your pedal feel issues, but not the fluid darkening?

Yeah I can't explain the fluid getting dark so fast. Only guess is something is getting too hot causing it. I was launching at 5,100 that night so wasn't taking it easy by any means. Cut a 1.76 60'. Still one day it went from new out of the bottle to black.

Shifting issues, replace the master and slave.

I'm going to try the new line first. Both master and slave are new mazda parts installed in 2013. But I'll replace them again if nothing else works.

Curious, what failure inside a master or slave cylinder would cause this problem? Leaking o-ring? Something else?

pretty good 60' time. what tires?

I was reading that the slave cylinder is more prone to darkening the fluid due to it's proximity to the ground and dirt/dust, and its large movement. I haven't taken the slave apart other than taking the plunger out and packing the boot with high viscosity amsoil grease. I'm assuming there is a thick o-ring / gasket...

oh, and what were your 1/4 mile results? I'd guess in the 11s at 110? but I have no idea. I'm a subaru drag guy.

I adjusted the clutch pedal so that it disengages wayyyy before my foot hits the floor. Same result as before, if not worse. I'm starting to think it's not the clutch at all, maybe it's the transmission? And it affects all the gears, I missed 2nd, 3rd, and 4th last night once it got 8-10 passes in a row worth of heat into it.

I think I'm going to swap the Ford fluid for some Amsoil and see if that fixes it or at least has any affect.

This helped me.

1 quart of MTG, 1 of syncromesh. It didn't fix it completely but it was better than the ferd stuff.

I just picked up some mopar stuff that made my gf's jeep transmission go from shifting like a screwdriver in a box of rocks, to a screwdriver in something smooth.

Its like $22 a quart though. Might be worth a shot.

Also emailed ACT, told them I bought this clutch used 8 years ago, and asked if it's still under warranty. :)

Interesting. Did you try straight MTG before doing the mix? Curious why you went with the mix. My syncro's seem to quit working when it gets hot.

I did not try straight MTG. The mix was recommended by a few people in my thread.