Clutch Delay Valve (CDV) delete, who has done it?

Hi all,

So I have been really contemplating deleting/removing the clutch delay valve on our vehicles recently. I feel like I have a very good level on understanding and skill of operating the manual transmission in my e92 m3 already, Ive had it for over 1 year now. Heel toes, rev match, etc have become very easy for me.

...The only thing which throws me off is the inconsistent shifting when trying to shift fast especially from 1st to 2nd gear or 2nd to 3rd. I feel like the grab point of the clutch is rather long but more so unpredictable. Will deleting the CDV be the answer to my solution? Sometimes I can do smooth crisp shifts and other times I find I will have to let the clutch out much slower (especially second half of the clutch travel) in order to execute a smooth shift.

Does anyone have any experience with this mod, are there any disadvantages of doing this? I know its relatively simple to do and so far I've heard very positive results, I just don't want to regret it. The only thing I've heard is it can possibly wear out the clutch more, but I'm not sure about that...thanks so much.

There is no clutch delay valve on the E9xM3.

Ditto pbonsalb.
.

You should also look into doing the clutch fan delete.

doogee wrote

You should also look into doing the clutch fan delete.

Also get your muffler bearings done for more HP

Hoooooooo boy, another common issues for E9x M thread, let's finally get this all in one spot shall we?

- DI pump and injector issue (check if you've had the latest recall done)
- Timing belts can fail
- Nikasil bore liners can cause a lot of oil consumption
- MAF sensors get dirty ALL THE TIME, hello check engine light
- CDV delete, must-have option, delete or the clutch will fail early (note you need two delete kits for the DCT)
- VANOS rattle TIMES FOUR
- Walnut blast the intake ports every 50,000 miles or less if you turn up the boost
- Wastegate issues
- Front sump/rear sump oil compatibility problems
- Secondary and primary cat videos

And that's just the engine/drivetrain stuff, you gotta watch out for subframe tearout and those runflat tires and the air springs going out too

I also recommend upgrading to cross drilled brake lines.

doogee wrote

I also recommend upgrading to cross drilled brake lines.

did anyone mention blinker fluid? definitely going to need some of that.

Unfortunately, you now can buy exhaust fluid. So that standby prank is no longer valid... So many laughs with that one.

But you can still send a guy to buy a box of spark plug gap.

that_grey_m3 wrote

Hi all,

So I have been really contemplating deleting/removing the clutch delay valve on our vehicles recently. I feel like I have a very good level on understanding and skill of operating the manual transmission in my e92 m3 already, Ive had it for over 1 year now. Heel toes, rev match, etc have become very easy for me.

...The only thing which throws me off is the inconsistent shifting when trying to shift fast especially from 1st to 2nd gear or 2nd to 3rd. I feel like the grab point of the clutch is rather long but more so unpredictable. Will deleting the CDV be the answer to my solution? Sometimes I can do smooth crisp shifts and other times I find I will have to let the clutch out much slower (especially second half of the clutch travel) in order to execute a smooth shift.

Does anyone have any experience with this mod, are there any disadvantages of doing this? I know its relatively simple to do and so far I've heard very positive results, I just don't want to regret it. The only thing I've heard is it can possibly wear out the clutch more, but I'm not sure about that...thanks so much.

jokes aside, you may get the biggest benefit from installing the UCP pedal. It provides more consistent application. Lots of people also remove one or two springs from the OEM clutch assembly

You guys are funny, I’m not as gullible as some and never buy into these fake auto parts. Last week my car was making a noise and I was told my “rod bearings” were failing I said psshhh nice try!

SYT_Shadow wrote

jokes aside, you may get the biggest benefit from installing the UCP pedal. It provides more consistent application. Lots of people also remove one or two springs from the OEM clutch assembly

I think this is one of my next few mods...need to do a little more research first.

Make sure you put in premium VTEC fluid and dont let it run low.

Jokes aside, look into a clutch stop. Best $10 I have ever spent. Takes away all the dead space in the pedal.

clutch stop and UCP pedal, best thing you can do to improve the clutch pedal feel and travel for the M3.

Richbot wrote

Hoooooooo boy, another common issues for E9x M thread, let's finally get this all in one spot shall we?

- DI pump and injector issue (check if you've had the latest recall done)
- Timing belts can fail
- Nikasil bore liners can cause a lot of oil consumption
- MAF sensors get dirty ALL THE TIME, hello check engine light
- CDV delete, must-have option, delete or the clutch will fail early (note you need two delete kits for the DCT)
- VANOS rattle TIMES FOUR
- Walnut blast the intake ports every 50,000 miles or less if you turn up the boost
- Wastegate issues
- Front sump/rear sump oil compatibility problems
- Secondary and primary cat videos

And that's just the engine/drivetrain stuff, you gotta watch out for subframe tearout and those runflat tires and the air springs going out too

This triggered my 335i ownership woes. Hard.

SYT_Shadow wrote

jokes aside, you may get the biggest benefit from installing the UCP pedal. It provides more consistent application. Lots of people also remove one or two springs from the OEM clutch assembly

This. ^^^ I removed one of the clutch springs from the pedal assembly a few months ago. NIGHT/DAY difference. Clutch isn't so soft anymore, which I wanted... And the engagement seems much more predictable and easier to replicate as well. Can't recommend doing this, enough. DIY below.

http://www.m3post.com/forums/showthread.php?t=195777

Loki Motorsports wrote

This. ^^^ I removed one of the clutch springs from the pedal assembly a few months ago. NIGHT/DAY difference. Clutch isn't so soft anymore, which I wanted... And the engagement seems much more predictable and easier to replicate as well. Can't recommend doing this, enough. DIY below.

http://www.m3post.com/forums/showthread.php?t=195777

I'd best most of the UCP advantage can be gained by just removing the friggin spring

And replacing the bushings with delrin or bronze.

SYT_Shadow wrote

I'd best most of the UCP advantage can be gained by just removing the friggin spring

I haven't had any experience with the UCP assembly personally, but judging simply from the spring removal benefits. I'm obligated to agree with you!

It depends on how sensitive your left leg is. The plastic oem clutch pedal arm does not give the same feedback and 'feel' that the metal UCP clutch pedal provide. The factory bushing also has a lot of play compare to the UCP pedal as one of the poster above pointed out also. I set the UCP to the stiffest (least assist) setting and loved it.

Hey guys, has anyone removed the clutch delay valve with a noticeable improvement? All kidding aside. My 2008 M3 has issues that sound like a clutch delay valve. I know the clutch was changed for 2009. I already did UCP and BMS clutch stop, which helped partially.

Richbot wrote

Hoooooooo boy, another common issues for E9x M thread, let's finally get this all in one spot shall we?

- DI pump and injector issue (check if you've had the latest recall done)
- Timing belts can fail
- Nikasil bore liners can cause a lot of oil consumption
- MAF sensors get dirty ALL THE TIME, hello check engine light
- CDV delete, must-have option, delete or the clutch will fail early (note you need two delete kits for the DCT)
- VANOS rattle TIMES FOUR
- Walnut blast the intake ports every 50,000 miles or less if you turn up the boost
- Wastegate issues
- Front sump/rear sump oil compatibility problems
- Secondary and primary cat videos

And that's just the engine/drivetrain stuff, you gotta watch out for subframe tearout and those runflat tires and the air springs going out too

make sure you check all of these first