Clutch issues

[markeddy]

Not sure if anyone else is having this problem. So here goes nothing...

When I am accelerating hard and reving it out to 5-6,000RPM and I shift from 2nd to 3rd it seems the clutch lags a little right before it engages again.

It almost feels like a catching or grabbing feel/light pedal feel the last 1/4 of the distance before I take my foot off the clutch to let it engage again.

Any help on this is much appreciated...maybe it's just free play or something that is mechanically set in the way the clutch engages under heavy acceleration during shifting....it just seems kinda odd....I have never experienced this before on any other vehicle.

 

[Mach 3.5 Turbo]

I'm a disc design engineer for a large clutch company (no foolin' ), so maybe I can give a little insight to this problem. I personally think that the disc for this car was most likely slapped together at the last minute rather than designed correctly. At extreme torque, a poorly designed disc's damper will "wind up" before you actually feel the clutch engage (the little springs in the center of the disc compress) while the springs between the inner and outer clutch facings ("segments") tend to slow the clutch engagement. This by itself can lead to a slow-release of the clutch (slipping under high torque). Basically, if the disc were tuned to the car's torque characteristics, this would never occur.

This is why racing clutches have no damper (center row of springs) and "pucks" instead of a compressible two-layer friction material. If you have ever driven a car with an undamped, puck-type friction material disc, you know that when releasing the pedal you feel almost nothing until the clutch violently engages.

The idea of having a two-layer friction facing clutch with springs in the middle is simply for comfort, so you can feel the clutch load up before engaging. This makes it much easier for the average person to drive the car, but lengthens the amount of time the clutch slips under harsh conditions. Just like a factory air intake sacrifices performance for a quiet engine, a factory clutch sacrifices performance for a smooth engagement, or a longer slip time under extremes.

I know it's long, but in summary: Could just be the damper in the middle winding up, but it's most likely the clutch slipping a little due to the segments between the inner and outer clutch facing slowing the engagement time of the clutch. Also might be due to a valve in the master cylinder that the MSP has that no other protege has (heard this on here somewhere). Theoretically causes the clutch to release pressure slower, also slowing the engagement time of the clutch. If you want to avoid this feeling, you're going to have to upgrade your clutch, or maybe "upgrade" the master cylinder. Anyone hear anything about this?

If you guys have any questions, let me know. If I don't know I can ask around at work and I'm sure someone'll have the answer.

 

[markeddy]

Thanks for the info Mach 3.5 Turbo. Since you have a Mazdaspeed 3.5 are you having this same problem that I am experiencing with your MSP?

Please let me know...thanks...

 

[Mach 3.5 Turbo]

Yeah, I am feeling it. I couldn't really tell if it's just my foot or the clutch, but it certainly seems to be the clutch slipping. This isn't necissarily bad for it, but it might wear out faster than if you drove it like a grandma. Don't worry about it glazing or anything, I don't think this small amount of slipping would really affect it's performance. I'll live with it until I can find some way to put a duel-mass-flywheel in my car, but I don't think anyone makes one with a strong enough clamp load yet.

 

[122 Vega]

There is a valve in the return line for the hydraulic clutch that slowly releases the pressure allowing the clutch to engage. If you are shifting quickly, you can feel the pedal come up before the pressure in your foot. There is a mod to remove this, but I don't think that anyone has done it on the MSP. The 1 gen DSMs have it too, search on their forums for the mod.

britt

 

[gcotton]

I have the same problem, I was seriously thinking about buying a upgraded clutch because its slipping. Is there something else to fix it.

 

[122 Vega]

You can do it with the car off, just let the pedal up real quickly and you can feel the lag in the pedal. So I don't think that it is slipping. Mine however does flutter upon engagement/disengagement, it is similar to the P5 TSB complaints. Into the dealer next week for that, again.

Britt

 

[Mach 3.5 Turbo]

The lag in the pedal is causing slipping at the clutch. The pressure that gets let out of the slave cylinder is slowed down by the valve, which in turn slows the onset of the clamp load on the disc. When the clamp load * the coefficient of friction of the disc is too low, the clutch slips. Has anyone tried just taking the valve out? You might get a little rough engagement, but it should clamp much faster.

 

[markeddy]

Thanks for all the information, it's most HELPFUL!!!

 

[Spooled]

One more thing that you might want to try (I am doing this soon) is get a steel-braided clutch line. This will eliminate any flex or expansion from pressure. I think Cork Sport has thm for cheap.

 

[funnylittlman]

the 03.5's have a modded clutch from the 03's w/ a stronger spring. You can REALLY feel the difference between the 2

 

[mazdaowner123]

When I let the clutch out fast in neutral or with the car off, I can feel it kinda catch, and it makes a noise audible from the engine bay, like a click almost. Is this the same thing you guys are talking about, or is this normal, or different? I feel kinda what you are talking about in the 1-2 shift but it feels more like wheelspin to me, but no noise of tires chirping (but our tires don't really make much noise). Mach 3.5 Turbo, thanks for the good info, you've been really helpful.

~brian

 

[RX-KEVIN]

122 vega you know your stuff (impressive). Every thing he said is true about the master cylinder (disc design engineer). I have had major clutch slippage recently, when trying to perform a second gear tach drop b-out. 23000 miles and I am in the market for a new clutch setup who do you work for disc design engineer?

 

[Dr.Sound]

the 03.5's have a modded clutch from the 03's w/ a stronger spring. You can REALLY feel the difference between the 2

exactly
the clutches between the 03 and 03.5 are like night and day.
when cold, my 03's clutch would slip badly untill the car warmed up.....and even then i would feel it slip under big load.

i even drove my buddie's 03 and felt the clutch slip.

the pedal feels heavier on 03.5

 

[island-p5]

I'm a disc design engineer for a large clutch company (no foolin' ), so maybe I can give a little insight to this problem. I personally think that the disc for this car was most likely slapped together at the last minute rather than designed correctly. At extreme torque, a poorly designed disc's damper will "wind up" before you actually feel the clutch engage (the little springs in the center of the disc compress) while the springs between the inner and outer clutch facings ("segments") tend to slow the clutch engagement. This by itself can lead to a slow-release of the clutch (slipping under high torque). Basically, if the disc were tuned to the car's torque characteristics, this would never occur.

This is why racing clutches have no damper (center row of springs) and "pucks" instead of a compressible two-layer friction material. If you have ever driven a car with an undamped, puck-type friction material disc, you know that when releasing the pedal you feel almost nothing until the clutch violently engages.

The idea of having a two-layer friction facing clutch with springs in the middle is simply for comfort, so you can feel the clutch load up before engaging. This makes it much easier for the average person to drive the car, but lengthens the amount of time the clutch slips under harsh conditions. Just like a factory air intake sacrifices performance for a quiet engine, a factory clutch sacrifices performance for a smooth engagement, or a longer slip time under extremes.

I know it's long, but in summary: Could just be the damper in the middle winding up, but it's most likely the clutch slipping a little due to the segments between the inner and outer clutch facing slowing the engagement time of the clutch. Also might be due to a valve in the master cylinder that the MSP has that no other protege has (heard this on here somewhere). Theoretically causes the clutch to release pressure slower, also slowing the engagement time of the clutch. If you want to avoid this feeling, you're going to have to upgrade your clutch, or maybe "upgrade" the master cylinder. Anyone hear anything about this?

If you guys have any questions, let me know. If I don't know I can ask around at work and I'm sure someone'll have the answer.

I have a 1.5 s-vt 130hp 5-speed i got a center force dual fiction about,7 months ago and slips real bad. see t got it from the USA,the 1.6 makes about 105hp, so if i change the p-plate would that help, and i never bled the clutch,after putting in the c-force .