Remove CDV
- Thread starter flybobbie
- Start date
A
Anonymous
Guest
What is a CDV?
Other than canine distemper virus...
Other than canine distemper virus...
Didn't want to spend too much time on the job, but i think the flexible hose would probably reach the slave cyl. which also has quick connector.
And thus remove and bypass the bendy bit of piping.
Left bendy pipe as not quite sure whats its for, might be for keeping fluid cool?
And thus remove and bypass the bendy bit of piping.
Left bendy pipe as not quite sure whats its for, might be for keeping fluid cool?
A
Anonymous
Guest
What does it do and why remove it?
I removed it because of an annoying judder when pulling away in first gear. Removing it stopped the judder. I think a fast gear change will always be a problem due the nature of the notchy gearbox. That and the steering the only two things that spoil the enjoyment of driving the car.
Actually never considered a BM before due their gearboxes, but fell in love with the shape.
Actually never considered a BM before due their gearboxes, but fell in love with the shape.
I thought it might just be me. I've considered removing the cdv but heard mixed reviews on doing itstayfrosty
Member
I am having the CDV removed this month when The Beast is serviced. Yes, some varying reports but what is the worst that can happen? Can't image the gearchage could get much worse!
Will update once done.
Silver grey MC
Mods: Strongstrut 3 piece / Stormwerks ST1 gearknob / clutch stop / stubby / ipod integration / LED interior
Work in progress: Exhaust tweaks
Will update once done.
Silver grey MC
Mods: Strongstrut 3 piece / Stormwerks ST1 gearknob / clutch stop / stubby / ipod integration / LED interior
Work in progress: Exhaust tweaks
stayfrosty
Member
Just got back from collecting The Beast from the garage after a full service and CDV removal. I also had them change the gearbox oil, just to help things still further.
What can I say? Just feels perfect now, no issues with trying to tiptoe around the gearbox and clutch. Highly recommended. Just annoyed the car left the factory with it in the first place!
Please note I also have Stormworks gearknob (500g of lovliness, I avoided the lightweight ZHP alternative) and a clutchstop fitted, and now believe I have one of the sweetest shifting Z4Ms on the planet!
Silver grey MC
Mods: Strongstrut 3 piece / Stormwerks ST1 gearknob / clutch stop / stubby / ipod integration / LED interior
Work in progress: Exhaust tweaks
What can I say? Just feels perfect now, no issues with trying to tiptoe around the gearbox and clutch. Highly recommended. Just annoyed the car left the factory with it in the first place!
Please note I also have Stormworks gearknob (500g of lovliness, I avoided the lightweight ZHP alternative) and a clutchstop fitted, and now believe I have one of the sweetest shifting Z4Ms on the planet!
Silver grey MC
Mods: Strongstrut 3 piece / Stormwerks ST1 gearknob / clutch stop / stubby / ipod integration / LED interior
Work in progress: Exhaust tweaks
This is on my to do list, hoping to do it myself one weekend soon.
Can anyone actually explain what the CDV does and I mean the engineer type response, not just ' it makes gear changes rubbish'. I am the sort of person who would just like to know how I am altering the car before removing something.
Can anyone actually explain what the CDV does and I mean the engineer type response, not just ' it makes gear changes rubbish'. I am the sort of person who would just like to know how I am altering the car before removing something.
Ok i dont have a full grasp so this might not be 100% correct.
But my understanding the CDV is to prevent harsh and sudden shocks causing damage to the DMF. From surges of power from say the clutch being drooped or poor gear changes. Its sole purpose is to protect the DMF from shock.
But my understanding the CDV is to prevent harsh and sudden shocks causing damage to the DMF. From surges of power from say the clutch being drooped or poor gear changes. Its sole purpose is to protect the DMF from shock.
Machine monkey said:
Yep that's it
basically slows down the clutch actionPosted from Tapatalk
CDV has a restrictor plate in it. It means that no matter how quickly you release your foot from the clutch, the clutch will engage at a constant speed.
So, when the clutch initially bites, it will take a split second longer to be fully engaged. This makes changing from 1st to 2nd gear very difficult to do smoothly.
When you remove the valve, it's like driving a normal car again.
So, when the clutch initially bites, it will take a split second longer to be fully engaged. This makes changing from 1st to 2nd gear very difficult to do smoothly.
When you remove the valve, it's like driving a normal car again.
I've left the CDV in place on the basis that I haven't noticed an issue and it's there for a reason, if BMW could save a few quid and delete it I guess they would? The only time I get up-changes a bit off is immediately after hitting the sport button as the throttle response is much sharper but you soon adjust. Not sure how CDV delete would affect this reaction?