Clutch delay valve mod, also ......

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kjb1
Joined: Thu 04 Feb, 2016 11:12
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  Z3 roadster 1.9

Clutch delay valve mod, also ......

Post by kjb1 » Sun 01 May, 2016 18:47

Hi, just querying this. I have a BMW Z3 2.8 on a 99' plate with the m52TU engine.

Lots of info already discovered on smoothing out the gear change. Would like to know if I need to physically remove cdv if I have one? or whether ai could do this mod here, which simply involves snipping a wire etc. Please view this link and let me know others thoughts. Talks of revs not dropping nicely without this mod.

http://www.bimmerforums.com/forum/showt ... -on-M52TUs




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bertiejaffa
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  M roadster S50
Location: Manchester

Re: Clutch delay valve mod, also ......

Post by bertiejaffa » Sun 01 May, 2016 18:55

you need to remove it - see page 2 of this thread to see that it physically reduces the flow

https://zroadster.org/threads/project-s ... 610/page-2
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kjb1
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  Z3 roadster 1.9

Re: Clutch delay valve mod, also ......

Post by kjb1 » Sun 01 May, 2016 19:15

why can I not simply do this wiring modification? mentioned in the link I posted would this not solve the issue?

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Brian H
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  Z3 roadster 3.0i

Re: Clutch delay valve mod, also ......

Post by Brian H » Sun 01 May, 2016 20:06

The CDV is a physical adaptor that restricts the flow of clutch fluid, if you want to get rid of the symptoms it introduces you need to remove it.

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kjb1
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  Z3 roadster 1.9

Re: Clutch delay valve mod, also ......

Post by kjb1 » Sun 01 May, 2016 20:18

what exactly is this wiring mod taking care of then?

is the cdv removal worth doing also? what part do I need to put a straight through in in place of it?


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Brian H
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  Z3 roadster 3.0i

Re: Clutch delay valve mod, also ......

Post by Brian H » Sun 01 May, 2016 20:34

kjb1 wrote:what exactly is this wiring mod taking care of then?

is the cdv removal worth doing also? what part do I need to put a straight through in in place of it?


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No parts needed if you remove, the CDV is an inline adaptor male to female, the clutch pipe will fit the clutch hose once removed.

I can only imagine that the mod above stops the ecu from knowing you have dipped the clutch and therefore does not effect the engine revs in any way, TBH never heard of this mod before. I removed my CDV years ago, makes a difference and puts you in charge of your clutch again.

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kjb1
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  Z3 roadster 1.9

Re: Clutch delay valve mod, also ......

Post by kjb1 » Sun 01 May, 2016 20:37

like it! a free fix!! nice one. Think I will also do the other mod and reverse if not happy.

Cheers


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Brian H
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  Z3 roadster 3.0i

Re: Clutch delay valve mod, also ......

Post by Brian H » Sun 01 May, 2016 20:40

kjb1 wrote:like it! a free fix!! nice one. Think I will also do the other mod and reverse if not happy.

Cheers


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Do the CDV removal first and give it a go, I don't think you will need to butcher your cabling after you have driven the car for a while.

peter2b
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  Z3 roadster 2.2i
Location: cheshire

Re: Clutch delay valve mod, also ......

Post by peter2b » Mon 02 May, 2016 17:45

I don't know if my face lift z3 has one as the clutch feels fine no judder just smooth gear changes unless my left foot feals sleepy
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motco
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  Z3 roadster 2.2i

Re: Clutch delay valve mod, also ......

Post by motco » Tue 03 May, 2016 09:27

These two different issues. The CDV is a pain because it damps quick but tiny clutch pedal movements such as we all make when manoeuvreing, but the 'mod' suggested in the link apparently makes the throttle behave more like a real physical cable operated throttle and, as such, would be desirable - if it works. My son has a Honda S2000 with a cable operated throttle and it is so much easier to drive and park with smoothness than the learner-like hunting and jerking that's foisted upon us by FBW throttle and CDV effects. He (son) also has a Z4M Coupé with a 'sport' button which has the effect of making it feel more direct. His CDV went in the bin too...

I can drive my Pinto engined Westfield more smoothly than my Z3 because the former has a cable throttle and clutch.

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motco
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  Z3 roadster 2.2i

Re: Clutch delay valve mod, also ......

Post by motco » Sat 07 May, 2016 11:47

Another thought popped into my head yesterday and that is to be very careful about carrying out this swicth removal mod in case the same switch is a cruise cancel switch. You could find that the engine races away if you dip the clutch on cruise and the switch is not there to cancel the cruise function. :oops:

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kjb1
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  Z3 roadster 1.9

Re: Clutch delay valve mod, also ......

Post by kjb1 » Sat 07 May, 2016 11:57

motco wrote:Another thought popped into my head yesterday and that is to be very careful about carrying out this swicth removal mod in case the same switch is a cruise cancel switch. You could find that the engine races away if you dip the clutch on cruise and the switch is not there to cancel the cruise function. :oops:
help if I had cruise ImageImage

but im guessing its been tried and tested as its a thread from USA, and Im guessing all cars got cruise over there.

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Brian H
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Re: Clutch delay valve mod, also ......

Post by Brian H » Sat 07 May, 2016 12:38

kjb1 wrote:but im guessing its been tried and tested as its a thread from USA, and Im guessing all cars got cruise over there.
Thats some assumption that because its a thread from the states its OK! Just like us, Cruse control will have been an option at the time of manufacture. If you do this mod let us know how you get on with it.

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kjb1
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  Z3 roadster 1.9

Re: Clutch delay valve mod, also ......

Post by kjb1 » Sat 07 May, 2016 13:30

Brian H wrote:
kjb1 wrote:but im guessing its been tried and tested as its a thread from USA, and Im guessing all cars got cruise over there.
Thats some assumption that because its a thread from the states its OK! Just like us, Cruse control will have been an option at the time of manufacture. If you do this mod let us know how you get on with it.
I don't have cruise control.

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