how does the slave cylinder delay valve affect the feeling on the clutch pedal ??
12-19-2018, 04:11 PM
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how does the slave cylinder delay valve affect the feeling on the clutch pedal ??
i read many posts about the delay valve del, but no one exactly talk how it affect the feeling on the clutch pedal.
the reason im asking is because on my 08 S2k,, whenever i shift aggressively at high RPM at any gear i can feel there is a restriction on the clutch pedal slowing me down on the up shift untill the RPM drop a bit. but when i drive normally everything feel fine.
so if i remove the clutch delay valve will my clutch pedal feel great again ??
thank you
the reason im asking is because on my 08 S2k,, whenever i shift aggressively at high RPM at any gear i can feel there is a restriction on the clutch pedal slowing me down on the up shift untill the RPM drop a bit. but when i drive normally everything feel fine.
so if i remove the clutch delay valve will my clutch pedal feel great again ??
thank you
12-19-2018, 07:00 PM
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The delay valve slows fluid movement through the slave cylinder. It's primary purpose is to reduce drivetrain shock by slowing down clutch release. The feeling will only be noticed during quick shifts.
12-21-2018, 04:53 AM
#5
What they said. Let me try and explain what it was like once it was removed. The cluth felt more direct. Crisp.
This felt good, but also amplifies mistakes. If you too abrupt with your engagement, the car, and any passenger, feel it. Not a bad thing, imo. Makes you a better driver.
What you describe sounds more like the heavy flywheel than the cdv. The ap2 flywheel is 22 lb. Ap1 is 14 lb. The heavier flywheel requires a slower shift speed. All that momentum. When its clutch time, plan on replacing flywheel with either an ap1 (budget) or aftermarket lightweight.
What you are describing could also be a slightly dragging clutch. Try doing the clutch rod adjustment (excellent youtube video on it), as well as changing fluid in mc reservoir, followed by a gravity bleed (look for diy).
This felt good, but also amplifies mistakes. If you too abrupt with your engagement, the car, and any passenger, feel it. Not a bad thing, imo. Makes you a better driver.
What you describe sounds more like the heavy flywheel than the cdv. The ap2 flywheel is 22 lb. Ap1 is 14 lb. The heavier flywheel requires a slower shift speed. All that momentum. When its clutch time, plan on replacing flywheel with either an ap1 (budget) or aftermarket lightweight.
What you are describing could also be a slightly dragging clutch. Try doing the clutch rod adjustment (excellent youtube video on it), as well as changing fluid in mc reservoir, followed by a gravity bleed (look for diy).
12-21-2018, 12:47 PM
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The restriction on the clutch pedal is most likely from the mechanical connection between your foot and the clutch.
There are 3 known points that create friction in that connection.
The two 'ball joints' on the push rod wear and lose grease and a polish & new grease will improve it a lot.
The push rod connects the slave cylinder to the clutch fork.
Also, the throw-out bearing slides over a guide, clutch dust, old grease and time make it harder to slide.
That's not so easy (quite impossible to be exact) to clean & regrease without removing the transmission.
There are 3 known points that create friction in that connection.
The two 'ball joints' on the push rod wear and lose grease and a polish & new grease will improve it a lot.
The push rod connects the slave cylinder to the clutch fork.
Also, the throw-out bearing slides over a guide, clutch dust, old grease and time make it harder to slide.
That's not so easy (quite impossible to be exact) to clean & regrease without removing the transmission.
12-31-2018, 10:45 AM
#7
Also, the clutch fork tips can be greased - with difficulty - with the transmission in place. I found that improved my clutch quite a bit. Not sure how long it will last. I want to inspect/clean/polish/replace the bearing guide. But, that job seems to require pulling the transmission. The sticky clutch syndrome can arise even with pretty low miles.
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01-06-2019, 10:41 AM
#9
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The CDV regulates fluid speed so the drivetrain re-engages at a set speed. On a fast, hard, dump of the clutch, the system will still engage at this pace because it protects the car from driveline shock. It's fast enough for a proper engagement with a set amount of cushion / slip similar to not dumping the pedal.
The AP2 with its 22lb flywheel will slip at redline shifts with or without the CDV - the OEM flywheel does not clamp down with sufficient force to stop the disc from sliding when there is that much energy in it.
A great way to easily test this is go take your CDV-equipped car out and do a rolling clutch drop at 5k rpm, 6k rpm, etc. You will not get any slip on a healthy system. Only at ~8k rpm do you get it.
You can remove a CDV for faster engagements, but to remove the redline slip, either shift slower or replace the OEM PP (~220Nm) with an ACT PP (~400Nm) that has about twice as much clamping force, or the ~22lb flywheel with the 00-03 ~12 lb flywheel, which halves the kinetic energy it can store.
My plan has always been to go the ACT PP route once my current clutch needs to be replaced, but I'm going on 15 years and 110k mi now...
The AP2 with its 22lb flywheel will slip at redline shifts with or without the CDV - the OEM flywheel does not clamp down with sufficient force to stop the disc from sliding when there is that much energy in it.
A great way to easily test this is go take your CDV-equipped car out and do a rolling clutch drop at 5k rpm, 6k rpm, etc. You will not get any slip on a healthy system. Only at ~8k rpm do you get it.
You can remove a CDV for faster engagements, but to remove the redline slip, either shift slower or replace the OEM PP (~220Nm) with an ACT PP (~400Nm) that has about twice as much clamping force, or the ~22lb flywheel with the 00-03 ~12 lb flywheel, which halves the kinetic energy it can store.
My plan has always been to go the ACT PP route once my current clutch needs to be replaced, but I'm going on 15 years and 110k mi now...
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