Stock CDV versus modified CDV Pics

[Templedogg]

I just install my modified CDV from Riss Racing. I can tell you already I notice a very nice difference. Most noticeable is that the 1st to 2nd shift is much quicker and smoother. A great mod that looks 100% stock as you can see and is pretty easy to install yourself. (I only needed the wife's help for 5 minutes to bleed the clutch)

Pic #1 - Stock CDV (notice how small the hole is)
Pic #2 - Modified CDV (notice how much larger the hole is)
Pic #3 - The way the stock CDV looks under the car
Pic #4 - The way the modifed CDV looks under the car...exactly the same. You would have to take it off and look inside to notice any difference!

[topvega]

I wonder if you cld just modify the stock onw with a drill bit and drill???

[Justin(OKC)]

Originally Posted by topvega

I wonder if you cld just modify the stock onw with a drill bit and drill???

I wondered the same thing. Someone should try it. We just need someone to measure the size of the opening on the modified CDV.

[Templedogg]

Yeah, but for the $30 cost it is not worth it to drill it and weaken it. Plus, it is so easy to plug the line with your thumb while you swap it out and lose almost zero fluid.

[topvega]

Originally Posted by Justin(OKC)

I wondered the same thing. Someone should try it. We just need someone to measure the size of the opening on the modified CDV.

Well if no one tries before I get mine I will give it a try... just need to find out the size difference between the two.

[InquisitiveA]

What's a CDV, and why is the stock one not very good.......??? :iono:

[Red135]

Originally Posted by Justin(OKC)

I wondered the same thing. Someone should try it. We just need someone to measure the size of the opening on the modified CDV.

In other CDV thread, someone said that if you try to drill the valve, it would melt.

[jeremyc74]

Originally Posted by Red135

In other CDV thread, someone said that if you try to drill the valve, it would melt.

They're just not going at it with the right tools. To do this you need to be using a drill press (or even better a mill) with a higher speed than a hand drill will get you. You also need to get the brake fluid cleaned off and use a proper drilling lubricant. For someone who's got access to the right tools it could be done with no problem, but IMO the replacement is so cheap it's almost a waste of time.

[Justin(OKC)]

I could see the melting issue, but as mentioned there are ways to take care of that. I would guess that high speeds would be more likely to melt it, but that's just my basic thinking and my history with dental handpieces and acrylic.

[Fl0rent]

Thanks for pictures.

Can you take one of car to locate the CDV.
I see that the CDV is under the car but where ?



Sorry for my english

[jeremyc74]

Originally Posted by Justin(OKC)

I could see the melting issue, but as mentioned there are ways to take care of that. I would guess that high speeds would be more likely to melt it, but that's just my basic thinking and my history with dental handpieces and acrylic.

Plastic machining is a funny business. You want the speeds way up with very low tool pressure. That way each revolution of the bit is taking a very small bite. At low speeds the bit will dig in and try to pull it's way into the plastic and then take off a large chunk. The chunk then gets spun around and around in the hole until the whole mess just melts.

Working around machine shops for 10 years will net you this kind of generally useless information :biggrin:

[topvega]

Originally Posted by InquisitiveA

What's a CDV, and why is the stock one not very good.......??? :iono:

This might help>>>http://www.1addicts.com/forums/showt...&highlight=cdv

[InquisitiveA]

Originally Posted by topvega

This might help>>>http://www.1addicts.com/forums/showt...&highlight=cdv

It did, thanks. :smile:

[Justin(OKC)]

Originally Posted by jeremyc74

Plastic machining is a funny business. You want the speeds way up with very low tool pressure. That way each revolution of the bit is taking a very small bite. At low speeds the bit will dig in and try to pull it's way into the plastic and then take off a large chunk. The chunk then gets spun around and around in the hole until the whole mess just melts.

Working around machine shops for 10 years will net you this kind of generally useless information :biggrin:

Ah, the key there is "very low tool pressure" and I totally relate to that. Betcha my drill spins faster than yours...haha! Thanks for the enlightenment.

[larryn]

Nice work, Templedogg!

[Aries932]

where did you get your modified CDV valve from

[larryn]

Search in the Commercial forum, or get one from zeckhausen.com :smile:

[Templedogg]

Originally Posted by Aries932

where did you get your modified CDV valve from

Welcome to the forum, but did you read my first sentence of this post?

[Rephlex]

Originally Posted by Fl0rent

Thanks for pictures.

Can you take one of car to locate the CDV.
I see that the CDV is under the car but where ?



Sorry for my english

I believe it is near the clutch.

[imported_volsfan0911]

http://www.zeckhausen.com

These guys sell a modified CDV which maintains the stock body and without the pitfills of drilling one out. When my 135i gets ordered, I'll be getting one ASAP. Installation is not terribly difficult from what I'm reading. They also will give you all the details on why it's there, how it works, why it sucks and how to get rid of it!