wolverine

I just had my CDV replaced using a Dave Zeckhausen modified CDV. The difference is unbelievable. I was grinning ear to ear when I pulled out of the shop. Anyone who enjoys driving a manual transmission should have this done.

The CDV from Dave was $35. The total labor cost from the shop was 1 hr - $80.

Now my car shifts like it should. I know exactly where the clutch pickup is, and my shifts are quick, smooth and precise. Heel and toe is far easier to match the rev?s. I can launch the car better, downshifting is smoother, upshifting smoother. Clutch pedal effort feels just right (maybe slightly increased, hard to tell), and now I can feel the clutch engage.

I replaced it figuring if I didn?t like it, I?d put the original back, and it would only cost me another $80. No way am I going back to the original CDV. I just can?t believe BMW put this ?thing? in between my foot and the clutch.

Man, what a difference.

mrbelk

It's awesome now, isn't it? It shifts like it should.

Have you considered getting a clutch-stop? The engagement zone is so high that I think a clutch stop would be a very useful addition to your CDV-less, EVO3 shifted tranny.

I'm strongly considering the EVO3 as well, so I'm anxious to hear how you like it after a couple thousand miles.

-MrB

heezy545i

Sounds good. I need to get around to ordering one.

wolverine

Installed a clutch-stop (just velcro'd a small block of wood to the floor under the pedal). What a difference - eliminated about 2" of clutch pedal travel. Less leg fatique, quicker, smoother shifts. Mr. Belk you were right - this is the way to go for those of us who are really into shifting!

Tuga

Can someone explaines me what's the CDV ?
Is it possible to change it? Is it better ? In my 530d is it possible to change it?
Please give me some info about this.

wolverine

From Dave Zeckhausen's website:

http://www.zeckhausen.com/CDV.htm#Th...of%20Operation

"The Clutch Delay Valve (CDV) is a one-way restrictor valve that BMW installs between the clutch slave cylinder and clutch master cylinder, as shown in Figure 1 below. Its function is to "delay" the engagement of the clutch, much like old record players used a damped tonearm to gently lower the needle onto the surface of the record.

No matter how quickly you lift your foot off the clutch pedal, the clutch always engages the flywheel at a constant (slow) rate. In theory, it can save the drive train from shock, were an inexperienced (or teenage) driver to suddenly dump the clutch at high RPM. But in practice, all it does is accelerate wear on the clutch and turn experienced drivers into people who suddenly, despite 20 years of practice, cannot shift gears smoothly. During parking maneuvers, the delay can be infuriating, causing constant slippage of the clutch. And during hard acceleration, the large amount of clutch slippage can greatly shorten the life of your clutch. During normal, sedate driving, the shift from first into second gear is often jerky, leading passengers to question your skill at driving manual equipped cars."

Go to the website and read the information Dave has, and give him a call if you're interested. He knows a lot about BMW's.

Tuga

Can i get the changed CDV here in europe?

wolverine

I would bet any good BMW shop can do it. You'll need to buy the modified CDV first - I would have Dave Z mail you one if he has them in stock.

JDN

wolverine/MrB -- will this mod endanger your warranty?

Gizmo

This is the $64,000 question (literally!!!) ...