CDV installed - thanks to Andrew @ Southern BM

[Zuzu]

Andrew...any thoughts on this mate?

Am I incorrect in my way of thinking?

[SimonB]

I find that the clutch in the 135 is far, far better than the one I am used to in the Falcon XR. Geez, that was a beast of a clutch - I think my left leg ended up thicker than the right after 5 years of that one!

I find I get a bit of a jerky takeoff in 1st and a bit in 2nd, in the 135, so was hoping that the CDV would alleviate that. However, that said, I am happy as is and would only do it if the consensus was that it wouldn't cause any problems.

[Breville]

I collected my mota this morning and did 350km's of varied driving and didn't have any clutch issues. Oh, apart from the stall at the first VERY steep hill..
But like mother says - I'm special :thumbup:

[andrew@southernBM]

Originally Posted by Zuzu

Andrew...any thoughts on this mate?

Am I incorrect in my way of thinking?

Zuzu, Yep your right. (Also Zuzu, and Kris, it is only clutch feel not gearbox related, you both seem to miss the point of what this does, Gearbox should be smooth, If your gearbox is knotchy now do not get a Short shift kit, even the BMW SSK is quite hard to change gears with a smooth gearbox).

Before 135i i have not changed them on mass before, there seems to be a real need for this with the 135i's here and overseas.

In my opinion the standard clutch feel is vague at the mid point and toward the lower end, it is the standard clutch feel of most late model manual BMW cars. As DTNJNQ said and as i explain to all the people who are interested in this, i believe it makes the pedal feel more linear throughout the range, you just don't feel that vague point in the middle and toward the end. It gives you what i describe as a proper clutch pedal feel.

All in all, if you like your pedal feel as it is, keep it, this isn't for you, i have many enquiries that after this exact discussion, have decided they like the pedal feel as is and have left it, it really is a personal choice. It is only an option for people who find it hard to drive without riding the clutch or are experiencing the vagueness in the pedal that i described.

I hope this answers your questions
Andrew

[harpoon]

I have the part but haven't had time to put it in yet.

I work in in financial markets

As soon as it's in I'm happy to pimp my car out for test drives to sydney-siders.

[Timbo]

Come on Harpoon... there's a line of Sydneysiders waiting here!

[WAY]

I think the best way to describe this mod is that you no longer have to ride your clutch so much in order to get a smooth shift. If you are getting a butter smooth shift with the OE CDV now, then you are riding the clutch. And this is the part I do not understand. How can it prolong the life of clutch (as I read somewhere else) but BMW putting this CDV in?

[Jase]

Yeah Zuzu, I also heard that it may reduce the life of the clutch. I am planning to cross that bridge when I come to it. Even knowing that it may reduce the life of my clutch I would still have the CDV mod done for the improved feel ( I didn't really think about it but when Andrew talked about the increased linear feel I would have to say I agree 100%).

I drive low klms so it is unlikely that I will have to replace the clutch in my time with the car ( unless it reduces the life expectancy significantly).

It is something I will be monitroing on the U.S. section cause if anyone is going to burn out the standard clutch it will be some of those guys ( due to the amount of Heavy launching and 1/4 mile sprints those guys do )..

[WAY]

It's not going to reduce your clutch life that significantly Jase! Afterall, every other car out there have the standard set up (ie. after doing the CDV delete).

[Zuzu]

Originally Posted by WAY

It's not going to reduce your clutch life that significantly Jase! Afterall, every other car out there have the standard set up (ie. after doing the CDV delete).

Wayne, I didnt mean CDV delete would reduce the clutch with normal driving conditions..:smile:

What I should of said that under hard/fast shifting through 1st,2nd and third you would get more wear and tear on the clutch components with the delete performed than stock.:wink:

And lets face it...we are all guilty of that type of driving ..Why else own a bi turbo..:biggrin:

[ozzy]

Hi Guys , sounds like a good mod to me , so where do we get it done in sunny sydney ?

[TimMc]

Originally Posted by Zuzu

my only concern then would be that you would accelerate the clutchplate/pressureplate wear.

This is the obvious reason the CDV is in place..
To slow down the clutch engagement process as to minimise wear in the clutch components..

I'd have thought that BMW was trying to protect the whole driveline by putting this restrictor in. If I sidestep the clutch at 7000rpm with the restrictor still in place then there may be enough clutch slippage to stop my universals/diff/gearbox disintegrating. If I try the same thing after the mod then there's a good chance something's going to break. Not that I plan on sidestepping my clutch when my 1 turns up...

[professor]

i have a friend, let's call him rosseforp. he was wondering whether he could use a clutch stop in conjunction with a cdv mod?

[BMWDave]

Originally Posted by professor

i have a friend, let's call him rosseforp.

Sorry prof, I don't have an answer for your friend rosseforp, but I find his creative name quite humorous.

[SimonB]

Originally Posted by BMWDave

Sorry prof, I don't have an answer for your friend rosseforp, but I find his creative name quite humorous.

Haha, me too. Or was that oot em?

[AussieRacer]

Originally Posted by TimMc

I'd have thought that BMW was trying to protect the whole driveline by putting this restrictor in. If I sidestep the clutch at 7000rpm with the restrictor still in place then there may be enough clutch slippage to stop my universals/diff/gearbox disintegrating. If I try the same thing after the mod then there's a good chance something's going to break. Not that I plan on sidestepping my clutch when my 1 turns up...

+1 - that was my understanding of what a CDV would do. Increase clutch wear to protect driveline.

[AussieRacer]

Prof, why does "rosseforp" (sounds a bit like Oprah's harpo company) want to install a clutch stop? Do you feel that you are depressing the pedal too far?

You use a clutch stop to reduce the time wasted by pushing the pedal further than necessary to disengage the clutch during quick gearchanges. It can have many other uses too in racing applications, but those are unique to the parts and construction/setup in racecars (eg. stopping the pedal getting stuck behind something in extreme situations, or popping slave cylinders).

[TimMc]

There's some good reading on clutch stops here,
http://www.rogueengineering.com/Merc...tegory_Code=CS
however with regard to late model beemers they state;
"Late model vehicles have a dual position, solid state clutch switch which requires the clutch pedal to be depressed nearly completely to the floor in order to start the vehicle. For these vehicles, the clutch stop cannot be adjusted to the limits of the clutch pedal engagement unless the clutch switch is modified. Modifications to the clutch switch are required to allow for both vehicle start and cruise control functions to be retained."
So I guess they can be made to fit and the CDV mod should have no effect I think?

[cuizhuoyi01]

Will the CDV make the clutch wear out quicker??

or the stock CDV make the clutch wear out quicker??

thanks

[TimMc]

Probably the stock CDV will wear the clutch more, but should protect the driveline more though. Replacing a clutch could be much cheaper than replacing a diff, gearbox etc. That said, I'll probably be removing my CDV.

[cuizhuoyi01]

I hear from somewhere many bmw run over 150000kms with stock CDV, and clutch still fine`

I already got the CDV from Andrew. but I feel ok with my clutch and gear shift. even when I quick shift, its still fine. I feel from 1st-2nd gear is easier to shift when I rev up above 5000, but its not really nice to shift below 3000. maybe i didn't used to it.

anyone know is there any good work shop for BMW around Gold Coast??

thanks

[Caduceus]

Originally Posted by TimMc

Probably the stock CDV will wear the clutch more, but should protect the driveline more though. Replacing a clutch could be much cheaper than replacing a diff, gearbox etc. That said, I'll probably be removing my CDV.

Tim,

I agree with you. It;s called a clutch DELAY valve for a reason. If you sidestep the clutch, it will delay the application of full clamping pressure to the clutch by restricting the flow of hydraulic fluid.

Now why would BMW do this? Once again, I agree with you and Aussie Racer. As they are making engines which develop so much torque and putting wide sticky tires on the back end, there is increased potential for breaking something expensive like a diff or gearbox if people just dump the clutch. By delaying clutch engagement, they are prepared to trade slightly increased wear on the clutch in order to preserve the rest of the driveline.

Like brake pads, clutches are expected to wear out eventually. And besides, if the clutch wears out in the warranty period, they can probably blame the driver for poor technique and possibly deny the claim. If the gearbox breaks under warranty, BMW will be up for the bill........ But perhaps not if they find out you have done the CDV delete.

Greg.