Road Rage

Haven't seen this before here, but if it is redundant, sorry:

The 2004 has a unique clutch delay orifice mechanism. It "improves clutch operation" by delaying the slave cylinder release speed when the clutch is suddenly released. This mechanism is built into the slave cylinder.

When the clutch pedal is released, the fluid prrssure from the master cylinder moves a 1-way valve. The clutch fluid passes through 2 passages: the orifice part and the filter part. It then flows out to the slave cylinder to release the pressure plate and the clutch disc.

When the pedal is released, the fluid pressure from the slave cylinder moves the 1-way valve blocks the filter-part passage and delays the clutch release speed by returning the fluid to the master cylinder through only the orifice-part passage.

So in short: When the pedal is pressed t goes through two passages - when released, through one.

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As I recall, BMW's have this as well. I am not sure whethger it is done for smoothness, or to protect the drivetrain against brutal clutch dumps.

It certainly begs the question: can you do a clutch dump on the MY04? The mechanism looks completely different than the 00-03, but probably could be bypassed, or the 00-03 fitted. Not sure though.

squibb

Good question. It might be my imagination but I think I felt this working on my car. I have not tried a full throttle start from a standstill yet in my car but I did feel something strange. I accelerate hard in 1st gear sometimes from about 3K RPMs. When I do this I feel a SLIGHT hesitation or bog in that area and then it goes away.........feels like it could be in the clutch. Not sure......just my 2 cents.

Road Rage

Not quite clear what you are saying - do you mean that when you are in gear and the clutch is engaged and you stomp on it in first from 3K, you feel a delay? The delay is built into the engagement process, and has no effect anywhere else.

Try just dumping it from say 1500 rpm (which should not hurt anything0 and let us know what happens. My car still has 311 miles on it and it is snowing here, so my Mad Scientist experiments are on hold.

squibb

This happens immediately after engagement. I'll try a burnout next week and let you know how it goes. I"ll try it before I install my Comptech blower (I am ordering it tomorrow).........hopefully the wife does not read anything on this board....HA ! I think it is supposed to snow here too, so I probably will not drive the car for a week.

Road Rage

As I understand it, it is supposed to delay before engagement, not after - but you have done it and I have not, so I defer to you (and your wife). Nice area up there (Glen Burnie) - too bad it is in the People's Republic of Maryland, site of my last speeding ticket, in 1978 (1 day later i ordered the then new Escort before Mike Valentine formned his own company). I am a staunch V1 man now.

leatherface_ca

well I tried dumping my 04's clutch at 5K rpm and yes you can dump clutch on the 04s

Destiny2002

Road Rage

I do not think there is much damage to be prevented in that situation - if the clutch is not spiiniing no wear occurs, and the differential does not benefit either - it might benefit from a slower engagement when running.

Road Rage

Thanks for the info.
Hmmmm - maybe it just adds a fraction of delay, but just enough to either add smoothness for "sloppy" drivers, or give the diff a little kindness. I will have to ask a BMY engineer I know.

AndyP

It's a smalllll world. My bro told me you got the S. Question is...how long will you keep this car?