I have a 1992 Impreza turbo with a 3 port boost solenoid, in the vent pipe (waste pipe) there is a small metal restrictor in it does this need to be fitted?? And does it matter where the vent pipe goes at the minute mine goes to a resonator box on the air filter, can this pipe just be left loose as long as the whole is blocked up on the air box?? The reason I'm asking is that I'm getting a custom silicone pipe made up and I'm wanting to remove as many restrictions as possible.

 

Also is the sensor to the left of my boost solenoid my map sensor??

 

Yeah, the pill is supposed to be in the bottom vac pipe - it helps control boost/prevent overboosting/smooths boost pulsing, etc.

And yeah, the OEM setup IS with it going to that port on the airbox (although it can be left hanging VTA, so long as you block the redundant port on the airbox with a screw or something, to make it all airtight).

Yeah the MAP sensor is the flat black square thing to the side with the 2 diagonally-opposed '45-deg. flats' i.e. an irregular hexagon, if you like.

 

Is the restrictor needed would it not make sense to remove it so the boost solenoid can get rid of the boost as quick as possible?

 

I see your logic, and that's what I used to think too.

But no, I think it would lead to overboost - it's required to temper the boost venting. Not entirely sure. PM/email Jolly Green Monster if desperate to know.

That said, if it was omitted, it might be able to 'mapped out' in a remap.

 

Well jgm is mapping my car in a couple of weeks Im just trying to make sure all is ready and my intake system has very little restrictions. I'll ask him before we start mapping see what he thinks!!! Thanks for your help.

 

Yeah, just turn up with car 'as is'... Then if there's any benefit in removing the pill prior to the remap, just replace that vac pipe with a bit of 3/4mm silicone (or simply push out the pill and reuse the OEM hose), and block up the airbox port.

That way you got both scenarios covered anyway.

Simon will see you right.

 

On my three port solenoid the outlet port is VTA with no restrictor. It was fitted by my maper.

 

If it is being mapped then vta is fine and no pill is fine

Map sensor is the small square black sensor about the size of a matchbox on your car.

Simon