Z4M CDV Removal / Delete or Modification?

[Anonymous]

So, I would like to take fully control of my clutch plate rather than it lagging behind me.

I did this modification on my previous car, which was an E92 335i. On the 335i I simply went to the dealer and bought a new CDV, which I then took into the garage and was able to press out the plastic restrictor which was inside the body of the plastic CDV casing.

Once the restrictor had been pushed out I was able to simply swap the CDV units over so my car effectively did not have a CDV.

After a couple of hours searching around on this subject, here and elsewhere, I still do not know conclusively what the best way forward is for the Z4M.

The Z4M CDV looks to be made of metal, not plastic like the 335i. It does not look like I can buy one from the dealer, push out the restrictor and bang it onto the car like I could with the 335i. Any modification would involve drilling the CDV, which I am not comfortable with.

Therefore, can I simply remove the CDV and plug the hose into the metal pipe going to the slave cylinder?

Some people were saying the hose is not long enough to do this.

I would appreciate some advice from someone who has done this to their ///M.

Thanks,

 

[Angus McCoatup]

Hello there.

Yes, you can just remove the CDV and join the two remaining ends together. The flexible hose will stretch far enough to bolt straight on to the steel hose.

This YouTube video gives a good idea of the amount of stretch available.

[youtube]PoB5ORUMdnE[/youtube]

Good luck with the DIY

 

[alastairb25]

I bought a UUC one, have a google, it deffo helped but ironically I personally feel fitting s tubby had as much positive impact on gear change feel, the CDV ust helped get rid of jerky feeling on low rev changes

 

[gwatson]

I removed mine completely. Wow, what a transformation coupled with the ZHP knob. I have no complaints now and I was critical after coming from one of the best in the business, the S2000.

 

[Rene_Z4MC]

Full removal on mine, no problems.

 

[Beedub]

removed mine completely..... if im honest not the HUGE difference i was expecting but their is a difference.... happy its removed.

 

[Vanne]

Got mine removed, to be honest, can't feel any difference...
Must be cos I am a crappy driver.

 

[Rene_Z4MC]

The CDV is a simple restriction device, fluid goes through a tiny hole.
I think whether there is a big difference or not has a lot to do with the viscosity of the oil.

Bought my ///M when it was relatively cold outside, clutch operation was slow/laggy until the car had fully warmed up.
I disliked it so much that I removed it within the first week of ownership and was really glad I did, big improvement.

IMO the main problem with it is that clutch behavior varies with conditions, its very difficult to get used to it.

So according my theory the difference between having a CDV or not will be small if you live in a country with hot weather, can anybody confirm?

 

[api330]

Remove the whole thing and do the clutch pedal stop mod as well and you will feel a big improvement,

 

[pharmed]

Whats the clutch pedal stop mod actually do? Seems to involve unnatural clutch movement?

 

[BonkersBM]

http://www.z4-forum.com/forum/viewtopic.php?f=9&t=57991

Here you go

 

[Anonymous]

Thanks for all the advice.

With the 335i, I replaced it with a modified unit so that the car would look normal on the ramp at the dealer in the event of a warranty claim.

Seeing as the Z4M is not under any sort of warranty, I will just remove the CDV and plug the pipe on to the metal pipe to the slave without it.

On the 335i it made a huge difference. It is difficult to explain but it feels exactly as it is to drive - your inputs on the clutch pedal do not mirror what happens at the plate so you often get excessive clutch slip or a jerky engagement because you ultimately don't have linear control from the pedal.

I wish BMW did not fit these stupid things to the cars. I understand why they do because I imagine it reduces warranty claims for transmissions, diffs, engine / gearbox mounts, etc from people who cannot drive a manual properly. However, the 90% of people who can end up with a significantly spoiled driving experience and a clutch friction plate which burns out probably 30 - 40% quicker than it would otherwise.

 

[Anonymous]

So, yesterday I had a look at how I would get the car onto a set of ramps - no chance. The front of it is so low that even with the ramps I have, which look to be pretty low, it is just not possible.

I like to work on my cars myself but on this occasion I threw in the towel and booked the car into a specialist called ETA motorsport who are located opposite the main entrance to Brands Hatch in Kent. Paid them £50 this morning to remove the CDV which included them bleeding the system afterwards.

The clutch is now as it should be, I have the control back! It really does make a big difference to the drive and enjoyment of the car.

If anyone else is feeling they struggle with the interface between them and the clutch, get the CDV removed. This is the third car I have done this on and it makes a huge difference.

 

[Rene_Z4MC]

Whats next, Vibra Technics engine mounts?
I can recommend them.

 

[Dangerous-Dave]

I had mine done on Friday, it makes a massive difference.

 

[Adamski]

Usually M owners report less of an impact - glad to see that CDV removal works on the M. Will make my driving experience if I get one next year

 

[Anonymous]

Whats next, Vibra Technics engine mounts?
I can recommend them.

Thanks. Just looked into it, they look quite well engineered compared to the OE part.

Looks like they are circa £120 each incl VAT. How many of them do you need?

 

[Angus McCoatup]

You'll need two of them.

They are beautifully engineered - shame they are pretty much hidden from view once fitted.

I got mine from Venom Motorsport for £110.54 each inc VAT.

http://www.venommotorsport.com/manu...egory=engine&product=Mounts&make=BMW&model=Z4

 

[Beedub]

i did really well and got 3 sets free of charge, for being the guinea pig for testing the competition set on my high Hp z4m..... 110% stand by this product....

the car uses the Race set, ive sold one set of road mounts to m5 and have one more new road set in my garage some-where..... i just cant find them if i can i will put a heads up in this thread.... ill take a look today as im off work.

 

[Woots]

i did really well and got 3 sets free of charge, for being the guinea pig for testing the competition set on my high Hp z4m..... 110% stand by this product....

the car uses the Race set, ive sold one set of road mounts to m5 and have one more new road set in my garage some-where..... i just cant find them if i can i will put a heads up in this thread.... ill take a look today as im off work.

I don't need engine mounts....I don't need engine mounts....I don't need engine mounts....even tho it's payday.....