installing c2 i/c on 930 q's
 

I have some questions on putting a c2 i/c on my 930. I am confused about the whole bov thing. Do I have to get the c2 style 90 elbow with bov? Can I use the stock elbow and put a bov in the aluminum tube after the 90? Unsure what is exactly needed to mount this..

Hi,
The BOV needs to be somewhere between the IC output and the Throttle body. The Vacuum/Boost control line for the BOV needs to come from just below the throttle plate. Here's where I put mine, it is in the front tank of the IC.


http://www.lesgarten.com/pix/porsche/AAA_1147.JPG
http://www.lesgarten.com/pix/porsche/AAA_1151.JPG

That's a VERY large TIAL 50mm. It makes a hell of WHOOSH when it blows.

Hope this helps.

Les

There is nothing set in stone...anything can be done. However, rather than re-invent the wheel as it were, I'd just spend the $45 for the C2 elbow and locate the compressor by-pass where the 965 had it. Keep in mind, there is already a port for the compressor by-pass valve on the front of the C2 intercooler (front as in reaching toward the front of the car), and this port makes for a very short run to the elbow. It makes for a clean install...

Also keep in mind that you should NOT vent to atmosphere with a CIS based engine.

EFI is a different animal...

Not that you need to spend anymore money on this addiction, but I'd think about going with one of the more stout, billet type compressor by-pass valves (CBV, diverter valve, dump valve, BOV, hooter valve, whatever you wish to call it). The 965 factory original plastic Bosch valve will work fine, but after some miles, is prone to wear and failure. I'm running a stealthy looking Hyperboost valve that looks just like the factory part, only it's anodized black billet aluminum. Forge makes a nice one too.

http://www.stratmosphere.com/hyperboost.htm
http://www.stratmosphere.com/forge_valves2.htm

sand_man, thanks for the info your other post made me drool enough to buy one of these guys. I just wasn't sure if I needed to use two divirter valve or one. It looks like one from the installs I have seen, but didn't the 964t use two stock?

les, that is sweet

964t used only one Bosch plastiv BOV of recirculating type. It works OK.

Open air BOV cannot be used on EFI either as long as EFI is using AMM.

Not that I'm aware. Keep in mind that your C2 intercooler is a long neck, so you'll be doing away with that large 930 diverter valve housing that fits between the throttle body and the stock intercooler. And instead replacing it with the small CBV that fits on the CIS elbow. I suppose it's possible that the other valve you might have seen in the 965 engine compartment was related to smog equipment.

Let me know if you need any pictures and I'll snap them.

And I agree, Les, that is SWEET!

Mine opens to atmosphere. What is AMM?

Les

Yea I was hoping to vent to atmosphere...I like the sound. Why can't you with these?

It causes the CIS flapper plate (in the metering housing) to behave erratically.

AMM = Air Mass Meter.

With CIS that flapper plate is basically a AMM :(

ok makes sense now. thanks for replies

Not quite, but it causes CIS to inject fuel that was previously metered up and then dumped overboard, causing an overrich condition.

And how does it do this? It's my understanding that it occurs via the flapper fluctuating. And FWIW, I've heard the inverse of what you just described...the flapper slamming shut and causing a lean condition. That's why I chose to say "erratic"...

BTW Goran, it's hard to tell from this whole internet thing, but I didn't mean my tone to have a defensive flair. I realize you know these fuel systems VERY well...in addition to turbo charging as a whole, and I respect your knowledge. And I do understand what you are describing. I'm merely pointing out what one of the more experienced shops in my neck of the woods explained when I was describing my plans to change intercoolers and run a different by-pass valve. Your explanation could very well be right one...

Cheers!

Go Ahead, I'm curious about this also. I have a 3.2 Manifold and have my BOV like I previously indicated in pictures in the above postings. Is there a problem with my BOV?
Les

does anyone know the part # for the elbow with bung for divirtor? I am trying to find it on ******** but not having any luck

I bought mine, here:
http://www.eagleday.com/rawagaexpi.html

thanks got it