Where does the line connect to ? (that has a line pointing to it)

 

Either plug it up or introduce pressure from after the turbo. that nipple is designed to allow pressure inside the valve to help keep it down (in other words to prevent BOV flutter)

 

You do not have to hook anything up to it, period.

 

You can cut a plastic straw into a "v" shape wedge. Stick it in there and it will make a nice "bird" sound every time you shift :P

 

That is not true. Pressure to that nipple will help open the BOV, not help close it.

Either leave it open (do not cap it off or you risk tearing the membrane inside the BOV), or give it a pressure source before the throttle plate, such as from and upper IC pipe. That will help eliminate partial throttle flutter or surge.

Eric

 

+1 TTP

www.evomoto.com - install page - how to is in there...

 

Why would it need help opening? That is what the boost pressure is supposed to do once you let off the gas. The way RRE has their Type S set up, there is a nipple on their adapter flange which routes to the nipple in question on the Type S. I am just trying to understand how it works.

 

It would need help opening in two situations:
1. Where you have the sping tension real tight so that you can run high amounts of boost
2. Part throttle lift-off

The first is self explanatory. Let me explain #2.

The top nipple only has vacuum when the throttle plate completely closes. If you are at WOT, boosting say 20psi, and slowly let off the throttle or let off to half way, then there is never any vauum in the upper line, which is what the BOV needs to open. The BOV will not blow off and all of that boost pressure and air needs to go somewhere. That is where the 'surge' or flutter comes from. The air bounces back off the compressor blades and build up enough pressure under the actual valve seat to open the BOV. This is what the fluttering is.

Hooking up the lower line to the upper IC pipe provides the boost pressure you are running to that lower nipple. So, in the same example, say your boosting 20 psi at WOT, then go to half throttle, that lower line still sees the 20psi, where the upper line sees less than that dues to the half closed throttle plate and the air escaping to the cylinders faster than it can pass the throttle plate. So, that pressure differential will open the BOV.

Hope this helps. Just remember the top nipple keeps the BOV closed with pressure, opens with vacuum. The bottom nipple opens with pressure.

Eric

P.S. There is a great tech article on DSMTalk back from like 2002, but the picutres are broken after their recent forum upgrade. It has great Autocad drawing that clearly illustrate the operation and insides of the Type-S. Just for reference, here is that link.

 

i just capped it off, but if you have the flange with a nipple , you can connect it (blue hose)

 

Makes sense. Thanks for the info.

 

Thanks very very much, you all were helpful.