Cdv removal clutch delay valve OMG!

[Marlon]

Really interested in this because I hate the 1 to 2 shift on my Z I find I have to alter the sequencing between my right and left foot differently (and more carefully) than any other car I have driven, to get anything like an acceptable pull away. Even then the shift feels very clunky, I assume this mod will make this better.

The only concern I have is I am not really following why did BMW fit it in the first place if it makes the gearchange a less pleasant experience, there must be some benefit of it being there (presumably it protects against something). If so what are the risks of removing it?

In short - none!

BMW fitted them to basically "protect the drivetrain from abuse" ie people repeatedly "dumping" the clutch, yup in a "sports car" so basically, no matter how quickly YOU release the clutch, it will only engage at the preset maximum speed allowed by the CDV.

Remove the CDV and YOU get the control of how fast & when it engages.

Mike

Also designed with the American market in mind to protect the clutch from drivers new to a 'stick shift' sports car

[Mr Tidy]

Really interested in this because I hate the 1 to 2 shift on my Z I find I have to alter the sequencing between my right and left foot differently (and more carefully) than any other car I have driven, to get anything like an acceptable pull away. Even then the shift feels very clunky, I assume this mod will make this better.

The only concern I have is I am not really following why did BMW fit it in the first place if it makes the gearchange a less pleasant experience, there must be some benefit of it being there (presumably it protects against something). If so what are the risks of removing it?

I'd really recommend getting the CDV deleted - it improves the car so much.

Fortunately the CDV had been removed from both my Z4s before I bought them, so they've always driven properly!

Removing it won't result in damage to anything else in the drivetrain so long as you drive it right!

[Hagasan]

Very interesting. I thought I had a super-heavy flywheel or a tired dmf! Gear changes definitely no great and not a sensation I find in other cars... Will be doing this mod at some point. I knew the change wasn't great but didn't know the reason why. Thanks for the info and details how to do it...

[Magicarcher]

Did this earlier today, the clutch appears much lighter, can feel the bite and 1-2 smoother.

[b19rak]

Local BMW Indy wants £80 to do this. I’d do it myself if I had the lifting equipment.

[Ducklakeview]

Local BMW Indy wants £80 to do this. I’d do it myself if I had the lifting equipment.

£80!!! It's a 10 mins job.... It's easily doable with a trolley jack and an axle stand....

Mike

[MACK]

Local BMW Indy wants £80 to do this. I’d do it myself if I had the lifting equipment.

That's a serious piss take. Most indies charge circa £35-£65 + vat an hour depending on who/where they are etc. With specialists changing £50-70 + vat an hour again depending on where they are. Most have a minimum charge of half an hour. but even so, thats double even the priceier specialists etc. Its usually more cost affective to get this done with other work when some will even do it as a freebie as it a quick job.

[jpvd]

Just did this on mine...but had the mechanic sort it - only took him 20mins

I used to find shifting from first to second and second to third a bloody nightmare, clutch felt heavy and sluggish and it just made town driving a nightmare. But with this thing thrown away it feels like it should... Light, easy to engage and smooth.... Wtf we're bmw thinking when they installed this stupid thing??....my guess it was for the yanks

So highly recommend, but be careful - you are messing with a line connected to your brakes... For £20 the mechanic can sort

[rdgreen]

Just did this on mine...but had the mechanic sort it - only took him 20mins

I used to find shifting from first to second and second to third a bloody nightmare, clutch felt heavy and sluggish and it just made town driving a nightmare. But with this thing thrown away it feels like it should... Light, easy to engage and smooth.... Wtf we're bmw thinking when they installed this stupid thing??....my guess it was for the yanks

So highly recommend, but be careful - you are messing with a line connected to your brakes... For £20 the mechanic can sort

Did mine last year and it made a small improvement....not the chalk and cheese some have reported. You do need to bleed the system after removing the CDV (some say you don't, but any time you crack a hydraulic line.....you do) and that may fix a problem you didn't know you had, like air in the system, which makes it feel better. By the way while the clutch/brake lines are connected directly to a mutual master cylinder, they are separated internally I believe. You don't want a clutch fluid leak leading to brake failure.

[jpvd]

Just did this on mine...but had the mechanic sort it - only took him 20mins

I used to find shifting from first to second and second to third a bloody nightmare, clutch felt heavy and sluggish and it just made town driving a nightmare. But with this thing thrown away it feels like it should... Light, easy to engage and smooth.... Wtf we're bmw thinking when they installed this stupid thing??....my guess it was for the yanks

So highly recommend, but be careful - you are messing with a line connected to your brakes... For £20 the mechanic can sort

Did mine last year and it made a small improvement....not the chalk and cheese some have reported. You do need to bleed the system after removing the CDV (some say you don't, but any time you crack a hydraulic line.....you do) and that may fix a problem you didn't know you had, like air in the system, which makes it feel better. By the way while the clutch/brake lines are connected directly to a mutual master cylinder, they are separated internally I believe. You don't want a clutch fluid leak leading to brake failure.

I definitely feel the improvement - lighter, which is probably due to the restriction being removed and easier to engage gears and not having to slip the clutch in first and second anymore... Glad I did it..

[Phippy]

Jamie, i noticed you have you licence plate in the windscreen... is this a permanent fixture? If so do you net get pulled over for it?

[Woodrow]

Having mine taken out tomorrow morning and a tooth in the afternoon.

[mr nurburgring]

Just done this mod, I’ll report back after my test drive if it’s wow,omg, can’t believe the difference.

[mr nurburgring]

There are many mods that float around on the internet that people rave about, I’ve tried many of these and none are worth doing, however, the CDV delete is the only mod I’ve done that actually makes a noticeable difference.

Removing this valve makes the drive pick up much more direct, none of the lag especially when you’re doing high Rev changes.

Mr Nurburgring approves this modification.

[Woodrow]

Glad I had this done. It’s completely changed the car in the lower gears. Should of done this when I bought the car 2 years ago.