Clutch Delay Valve

Dinan55 · Nov 18, 2003

I found out a few days ago why it's so hard to make my car not shake when I shift. It has some sort of "clutch delay valve." It's some kind of device that no matter what you do with your foot the clutch will always come down smoothly. I don't like the idea of this and I'm considering taking it out. I've heard people have done it, and none of the M cars have it.

What do you guys think?

Dinan55 · Nov 18, 2003

http://www.bmwtips.com/tipsntricks/cdv/cdv.htm

xLibelle · Nov 18, 2003

for better response, yeah, take it out. but i dont know what the difference could be like. it sounds like it might be a good ting unless you had some serious mods to the clutch and engine.

frolf · Nov 19, 2003

i think the E39 M5 has something that does the same thing, its called a dual-mass clutch/flywheel. the reason bmw used it on a highperformance car was to smooth out the idle, though a standard clutch is availible from dinan.

Dinan55 · Nov 19, 2003

frolf said:

None of the M cars have this thing. M drivers are willing to sacrifice luxury for performance so they don't put it in. The M5 has a heavy-duty clutch/flywheel because with power like that of the M5 and the insane drivers who own them, you need something that can take the abuse.

MrElussive · Nov 20, 2003

I believe most manual transmission cars have this clutch delay valve. It is to prolongue the life of the clutch and the transmission. You CAN make it smooth for your passengers when you are shifting. Let's say you're going from 1st to 2nd, accelerate in 1st all the way to 3K rpm and stop accelerating...don't keep accelerating past 3K (assuming you want to shift at 3K). While holding the accelerator, gently push the clutch in while slowly letting off the accelerator, and then shift to 2nd like you normally do, but make sure you catch the rpm's at the right time. You basically need to be more gentle about it. Personally, I have been practicing this technique as much as possible as it really works...my passenger(s) don't go back and forth anymore...it's not second-nature the way normal shift is for me, but soon it will be. [;)]

frolf · Nov 20, 2003

Dinan55 said:

but M5's do have dual mass my friend.

Dinan55 · Nov 20, 2003

Dual mass/heavy duty... what's the difference?

frolf · Nov 23, 2003

Dinan55 said:

enough to need clarity. if you drop the clutch on an M5 it will feel like its slipping, but its not, its the second part of the flywheel catching up with the first. i would consider that just normal dual mass, i would consider dinan's standard flywheel/clutch setup as heavy duty, having to deal with the M5's massive amount of power straight up.

MrElussive · Nov 23, 2003

The M5 has a stiff clutch.