CDV delete -- E46 BMW

[Cadeez]

Anyone here done it personally on their car, or had it done? Sounds like a great mod that's basically free. Seems kind of like an appendix, it was put there for some reason yet you don't really know why and you can live without it. I need a weekend project, looking for input, thanks.

Found this DIY, not sure if it's legit though...
http://www.zeckhausen.com/CDV.htm#Benefits

[bullfrogs_M3]

Did it on my car. Easy 15 min job. Although I honestly couldn't tell the diff though because I also did UUC tranny mounts and OEM BMW ssk at the same time

[RITmusic2k]

Dane will probably chime in soon; he did it super quickly as well. I was going to do it a couple weeks ago, but I couldn't locate a proper lifting point to get my car raised with my racing jack :(

[bullfrogs_M3]

You can use my buddies site for further install instructions: http://www.my330i.com/mod27.php


ZECKHAUSEN MODIFIED CLUTCH DELAY VALVE
Completed 4/28/2004
DESCRIPTION
Replace stock Clutch Delay Valve with modified Zeckhausen unit.
PARTS NEEDED
1 - ZECKHAUSEN MODIFIED CLUTCH DELAY VALVE
(ZECKHAUSEN RACING $35)
TOOLS NEEDED
11mm Flair Wrench
15mm Wrench
Clear Rubber Bleeder Hose and Bottle
Brake Fluid

INSTALLATION
Most modern manual transmission BMWs come with a Clutch Delay or Lock Valve (CDV). The purpose of this valve, according to BMW, is to smooth out shifts and extend the life of driveline parts. It functions by only allowing hydraulic fluid to pass through it at a certain rate. Since it is inline on the clutch system, it effectively removes the ability to control your clutch use manually. It was designed to make the car nicer to drive for the average person. If you are reading this, you are not that average person! The CDV "dumbs" down the clutch pedal feel, and under hard driving, will actually cause the clutch disc to wear out *faster* due to slower engagement at high speed.

Thanks to the great people over at Zeckhausen Racing, they will provide BMW owners with a modified CDV for a small price, or modify one you send them, or provide you one for *free* if you send them two (2) stock original CDVs. Zeckhausen safely removes the internals of the CDV (without drilling) allowing it to go back into factory OEM location but now without interfering with clutch operation. These are modified factory parts and look, feel, and fit the same as your existing stock valve.

1. Park the car on a level surface and set the parking brake.

2. Jack up the front of the car and support it with jackstands.

3. Right forward of the clutch slave cylinder is a mounting point for the hydraulic line. The clutch delay valve can be see here both in and out of the car (Photos A & B).

4. I used a small plastic pair of locking pliers to crimp the rubber supply line about 3" away from this mount. This will keep excess fluid from draining out when you remove the CDV.

5. Using a 11mm Flair Wrench, disconnect the metal piping from CDV and pull the CDV from the bracket. A Flair Wrench grabs a nut/bolt on all six sides and is specifically designed to remove brake line and other hose nuts (Photo C). Be sure to use the correct tool for the job!

6. The CDV can then be removed from the supply line with a 15mm Wrench.

7. Replace with the modifed CDV and reconnect the lines. Hydraulic lines are flaired and need to be snug, but not overly tight.

8. Remove the hose clamp and prepare to bleed the clutch slave cylinder.

9. Open the hood and check that you have plenty of brake fluid in the master cylinder. The master cylinder feeds both the brakes and clutch system (Photo D).

10. Remove the rubber nipple on the slave cylinder bleeder screw (Photo E). Attach a length of rubber tubing and run that tubing into a small clear container filled partly with fresh brake fluid. You want to keep the end of this hose submerged at all times to keep air from creeping back into the system.

11. Attach a 8mm wrench to the bleeder valve and have a friend pump the clutch pedal a few times and then hold it down.

12. Open the bleeder for just a second. You will see the bubbles and fluid shoot down your rubber hose. Close the bleeder.

13. Have your friend pump the clutch pedal again and hold it. Again, crack the bleeder for a short period and close it.

14. I only needed to do this 3 times and I no longer saw bubbles. The system was now bled. If you have to do it more times than this, be sure to check on the master cylinder level periodically to make sure you have plenty of brake fluid and top off as needed.

15. Replace the bleeder nipple, check your connections for leaks, and go take it for a drive, you will notice the difference immediately!

[az3579]

DHHHUUUUUUUUUUU EEEEEEEEEEEEEEEEEEEETTTTTTTTTT!!

This is simply one of the MOST effective mods I've done to my car. It makes rev-matching possible!

[spencers]

Yep

[Crickett]

+1 Did it; dhuuu eeeet.

[kpro]

I did it. I took the cdv out and just connected the two lines togheter. I didn't buy a special cdv or anything. The difference is night and day, IMO.

[Cadeez]

Awesome, I'm gonna do it as soon as I can get it on a lift, thanks all!

[gr330zhp]

I did it when I swapped my tranny and diff fluid, makes an awesome difference and was really pretty quick to do


DHHHUUUUUUUUUUU EEEEEEEEEEEEEEEEEEEETTTTTTTTTT!!

This is simply one of the MOST effective mods I've done to my car. It makes rev-matching possible!

This, just need a throttle cable to perfect rev-matching. I hate Drive by wire, it makes a noticeable delay in response :(

[Crickett]

This, just need a throttle cable to perfect rev-matching. I hate Drive by wire, it makes a noticeable delay in response :(
Exactly why I'm beginning to consider a Sprint Booster or equivalent . . . !CDV helps, but it's only half of the equation.

[gr330zhp]

Exactly why I'm beginning to consider a Sprint Booster or equivalent . . . !CDV helps, but it's only half of the equation.

This exactly!

Sent from my HTC Desire using Tapatalk

[nike001]

To the people that said that the CDV delete makes rev-matching possible..

Are you saying you couldn't do it before? I can almost perfectly rev-match now with the CDV.

[gr330zhp]

To the people that said that the CDV delete makes rev-matching possible..

Are you saying you couldn't do it before? I can almost perfectly rev-match now with the CDV.

Depends on the change of gear and rpm. If is a small amount as in a normal downshift it isnt bad. But for example I wanted to keep up with my dad in my moms B8 S4 yesterday, I downshifted from 6th to 4th, trying to revmatch plunging the pedal, but the response was soo delayed. Nothing wromg, just how drive by wire operates.

Anyone ever driven a preracelift E39 540i with throttle cable 282hp M62 and then a facelifted with the drive by wire M62TU? 8 more hp and feels soooo much doggier. Still quick but there is a difference

Sent from my HTC Desire using Tapatalk

[az3579]

This, just need a throttle cable to perfect rev-matching. I hate Drive by wire, it makes a noticeable delay in response :(

I can actually get perfect rev-matches right now as my car sits (Shark Injector, CDV delete), but I still get less perfect rev-matches than I got with my E30.


To the people that said that the CDV delete makes rev-matching possible..

Are you saying you couldn't do it before? I can almost perfectly rev-match now with the CDV.

I could do perhaps a 95% rev-match with the CDV, but I still felt a little "jolt", so minor, yet so noticeable. It still bugged the hell out of me that I was doing everything right but I couldn't dump the clutch without that stupid little judder.



Anyone ever driven a preracelift E39 540i with throttle cable 282hp M62 and then a facelifted with the drive by wire M62TU? 8 more hp and feels soooo much doggier. Still quick but there is a difference



I have. My brother's car was a 1997 540i with a 6-speed, and was the first manual car I learned to drive on. The throttle was nice, but the CDV made it almost IMPOSSIBLE to learn manual on. I started with the mentality that "this is going to be easy" because I already knew the concepts behind it, just never put it into practice. Then, when I went to apply those concepts, it all went to hell because of that stupid valve. I could never get a smooth start with it.

Then I went to a 75hp Russian car, that wouldn't even have a CDV as an option (It didn't even know what an option was, that's how basic the car was). I was driving manual smoothly within half an hour in that car.

The next time I drove a car with a CDV was my buddy's 2001 E39 525i. That also has a CDV, and those bad memories of a CDV in my brother's car came right back; it was very difficult to get used to. By the time I drove the 525i, I already was rev-matching perfectly in my E30, so my skill was great. Goes to show you how badly it messes someone up.

Then I got my car. I could rev match almost pefectly, but the fact that I could never rev-match 100% perfectly bugged the hell out of me. So, in essence, the CDV delete is probably the best mod I've ever done and will remain that.

[PKR]

I'm with you az3579 ... I learned on a 1948 Jeep (no synchro on first!) so I know about rev-matching. That CDV is headed for the trash next chance I get !

[sarmen]

Like the title says,

Has anyone changed their clutch delay to a modified clutch delay?

if so did you notice a big difference, good or bad one?

[Marcus-SanDiego]

Sarmen, I am going to merge your thread with this one: http://www.zhpmafia.com/forums/showthread.php?2122-CDV-delete

[M0nk3y]

I'm going to see if I can get my dealer to remove my CDV.

Lol we'll see how this goes...

[az3579]

I'm going to see if I can get my dealer to remove my CDV.

Lol we'll see how this goes...

Don't hold your breath.

[danewilson77]

Like the title says,

Has anyone changed their clutch delay to a modified clutch delay?

if so did you notice a big difference, good or bad one?

I performed the CDV delete after purchase and noticed a small difference.

[Cadeez]

Can someone please tell me where the CDV is physically on the car?? I've got DIY's and input coming out of my arss, but no info as to the physical placement/location of the valve itself. Please help

http://forums.bimmerforums.com/forum/showthread.php?p=20808952#post20808952
http://www.zhpmafia.com/forums/showthread.php?855-CDV-delete
http://www.zeckhausen.com/CDV.htm#Benefits

[Alphatek45]

Drivers side of tranny. Near clutch bleed valve. Can't miss it.

[RITmusic2k]

Best tutorial I've found so far - lots of good pictures and excellent instructions:

http://www.madrussian.net/m3/diy_cdv.shtml (http://www.madrussian.net/m3/diy_cdv.shtml)

[danewilson77]

Drivers side of tranny. Near clutch bleed valve. Can't miss it.

Yeah...by the......clutch....hehe.

HTC Thunderbolt+TT

[Cadeez]

Drivers side of tranny. Near clutch bleed valve. Can't miss it.
Copy that, makes sense haha

Best tutorial I've found so far - lots of good pictures and excellent instructions:

http://www.madrussian.net/m3/diy_cdv.shtml (http://www.madrussian.net/m3/diy_cdv.shtml)
Awesome thanks!

Yeah...by the......clutch....hehe.

HTC Thunderbolt+TT

Haha Dane, figured you'd say that...

[KC ZHP]

Piling on the bandwagon here - finally got around to doing this the last time I bled the brakes... Should have done it much sooner! This, along with adding a clutch stop are quick and inexpensive ways to improve the driving experience of these cars.

[webster]

bump. i want to do this sooo bad. #1 complaint of my ZHP so far, and actually the only complaint now that my tire noise issue has been addressed, is the herky 1-2 shift. at first i thought it was just me getting reacquainted with driving stick. but after 2 weeks of driving and doing 30 mins of research i know it's gotta be the CDV...

soooo...if i buy a modified CDV from Zeckenhausen, is it reasonable to take it to the shop to have em swap it out?

[Katu]

I just did this last week. You don't need to buy a modified CDV from anyone. You can simply have the shop remove your CDV and reconnect the line (there is enough slack). No extra parts needed. Then bleed the line.

This is the DIY I used:

http://forum.e46fanatics.com/showthread.php?t=763107

[PKR]

I just had the dummy valve installed, while the car was in for other service. Very noticeable improvement for me.

[llll1l1ll]

Oh man, this CDV explains a lot about why I suddenly feel like I can't shift right anymore after switching to the ZHP. I may have to do this at some point in the future.

[danewilson77]

Oh man, this CDV explains a lot about why I suddenly feel like I can't shift right anymore after switching to the ZHP. I may have to do this at some point in the future.

15 minute diy brutha.

[llll1l1ll]

Yep, I just gotta get me some ramps. If I do the CDV, it would probably be an opportune time to replace the gearbox fluid, as well.

[webster]

just bought the zeck modified CDV

having it installed next week when i replace the cabin/air/fuel filters :)

[SureShot434]

I will def do this while changing my power steering pump