[paul e]

Okay....other than a 2 year period when I drove a 1962 V8 Impala with Powerglide I’ve driven manuals my entire life since age 16....I’m 65 now.

I’ve never heard of a Clutch Delay Valve.

Nor do I understand the need for one.

Some please explain the need for this device. Thanks.

[kern417]

The purpose is to soften the engagement/disengagement of the clutch to improve driveability and help protect your transmission from shock loading.

[kern417]

Originally Posted by Incontinentia Buttocks

I would argue about the driveability bit. Quite usual in the UK to remove the CDV. To improve driveability

It softens the engagement to ensure you get smooth takeoff and shifts. I haven't had any issue when driving slowly, otherwise the delay isn't noticeable. IMO a bigger issue for smooth driving is rev hang, but that's another subject.

The main issue caused by the CDV is when trying to quickly accelerate from a stop or shift fast, but the clutch delay prevents that from happening.

[jparnes1]

If you're looking to modify the CDV in your F3x, this was recently posted in this forum. I just did it myself

[JJS]

Originally Posted by kern417

It softens the engagement to ensure you get smooth takeoff and shifts. I haven't had any issue when driving slowly, otherwise the delay isn't noticeable. IMO a bigger issue for smooth driving is rev hang, but that's another subject.

The main issue caused by the CDV is when trying to quickly accelerate from a stop or shift fast, but the clutch delay prevents that from happening.

I can't say I've noticed any deleterious effects from the CDV in my F31. Maybe I'm not trying or driving hard enough.

[jparnes1]

Originally Posted by JJS

I can't say I've noticed any deleterious effects from the CDV in my F31. Maybe I'm not trying or driving hard enough.

It's not just that. The CDV works by allowing clutch slippage, so over the long haul your clutch will wear faster. If you're experienced with shifting, you don't need it.

[JJS]

Originally Posted by jparnes1

It's not just that. The CDV works by allowing clutch slippage, so over the long haul your clutch will wear faster. If you're experienced with shifting, you don't need it.

I've been driving MT cars for almost forty years. I think I'd know if the clutch was slipping. Dumping the clutch or power-shifting are not regular habits of mine. I have far too much mechanical empathy for my vehicles. So if it takes an extra half a second to fully engage (so long as road speed and engine speed are more of less aligned) I don't think clutch wear will be factor. I dare say that a single hard launch will wear the clutch more than a thousand well timed shifts with the CDV intact. As usual, YMMV.

[kern417]

Originally Posted by JJS

I can't say I've noticed any deleterious effects from the CDV in my F31. Maybe I'm not trying or driving hard enough.

Like I said, when driving regularly it shouldn't be an issue. But say your foot slips off the clutch during engagement or you jump into your F30 after driving a truck all weekend and slam the pedal thinking there will be more resistance. The CDV just limits the max speed of engagement. I've even had situations where you slam into gear and the car cuts power to protect the drivetrain.

Originally Posted by Jrboulder

My understanding is that it slows the travel of the slave cylinder piston by creating a restriction in the hydraulic circuit. I'm not sure if the master cylinder has a built in accumulator-like system or if it just relies on the hose swelling under pressure.

The "accumulator" is the brake fluid reservoir.