PDA

View Full Version : JST, time to remove your CDV


undefined
12-15-2003, 04:18 PM
http://members.roadfly.org/ump/Dcp00185.jpg

#15 below:
http://members.roadfly.org/rs2/cdv.jpg

JST
12-16-2003, 12:18 AM
Yeah, I've been following that. Have you deleted yours? Any feedback on feel? I actually don't have that many complaints about the clutch engagement on the E46--it gives a much more positive engagement than the E36 did.

undefined
12-16-2003, 12:21 AM
Yeah, I've been following that. Have you deleted yours? Any feedback on feel? I actually don't have that many complaints about the clutch engagement on the E46--it gives a much more positive engagement than the E36 did.

No, I haven't. I would think about it if I was not selling it next year, but like you, I really have had no complaints about my clutch feel.

The HACK
12-16-2003, 06:55 PM
So it appears...

E46 M3s with manuals have CDV.
330i with ZHP has CDV.
Xis have CDV.

I've yet to confirm late model 330i/Cis having it, although the one 330Ci that I looked didn't (Raffi's car), although it's early production. I've heard people with later ('02) 330i/Cis complaining that their clutch engagement is extra vague, and I have confirmed that driving Doeboy's car. May be a rolling change per '02 production.

Z4s with 3.0 liter engine supposedly has the CDV as well, although I can not confirm until I can get a car up on a lift. NONE of the SMG equipped cars will have the CDV (clutch slave cylinder assembly is completely removed for the SMG hydraulic controller).

At the next techsession I will put out a call for various other models, 330/325, Z4...etc to confirm a few other model that's missing from the list. I know 325iTs do not have it (checked Kazuto's car), I know 323Cis don't have it.

Pike
12-16-2003, 09:17 PM
I was thinking about my M3, which is tricky to shift smoothly from 1-2nd, mostly because the clutch travel is too long for my liking, and the engagement point is a little too high so I end up feeding the gas too early.

But I don't recall the clutch behaving like it has a CDV. Of course, maybe I'm just so used to it I can't discern it. Mostly, my clutch seems happy to engage instantly if I'm dumb enough to let it out too quickly, resulting in wheel spin or at least some jerking from the driveline.

The HACK
12-16-2003, 10:22 PM
I was thinking about my M3, which is tricky to shift smoothly from 1-2nd, mostly because the clutch travel is too long for my liking, and the engagement point is a little too high so I end up feeding the gas too early.

But I don't recall the clutch behaving like it has a CDV. Of course, maybe I'm just so used to it I can't discern it. Mostly, my clutch seems happy to engage instantly if I'm dumb enough to let it out too quickly, resulting in wheel spin or at least some jerking from the driveline.

If you look at the location in which the E46 CDV is installed, it's installed in REVERSE of how the CDV is installed on the E39. I cant' quite figure out if this is having a different effect or sensation compared to how the CDV works on the E39.

Nick M3
12-16-2003, 10:57 PM
I was thinking about my M3, which is tricky to shift smoothly from 1-2nd, mostly because the clutch travel is too long for my liking, and the engagement point is a little too high so I end up feeding the gas too early.

But I don't recall the clutch behaving like it has a CDV. Of course, maybe I'm just so used to it I can't discern it. Mostly, my clutch seems happy to engage instantly if I'm dumb enough to let it out too quickly, resulting in wheel spin or at least some jerking from the driveline.

If you look at the location in which the E46 CDV is installed, it's installed in REVERSE of how the CDV is installed on the E39. I cant' quite figure out if this is having a different effect or sensation compared to how the CDV works on the E39.

What do you mean? It's not actually a valve. It actually just constricts the flow of hydraulic fluid.

This image illustrates it well:

http://www.nrubenstein.com/images/cdv/cdv3.jpg

The HACK
12-16-2003, 11:09 PM
Right. On the E46 it constricts the fluid from flowing back into the master fluid reservoir, on the E39 it constricts the fluid from flowing from the fluid reservoir into the slave cylinder. The end that THREADS into the CDV has a wider opening than the end that it comes out of. The E39s have the CDV threaded into the slave cylinder opposite of the E46.

Maybe all it is is two conical shapes meeting in the middle to create a restriction...If so then it doesn't matter where it's installed and it'll serve the same purpose.

doeboy
12-17-2003, 03:44 AM
Hrmm... I guess we can check it out on mine too next time we have a get together.

Raffi was saying my clutch felt better than his though... :dunno: :scratch: