boost pressure solenoid
 

I have a few questions. i have a 90 turbo and i wan to remove all my solenoids... Here is what i understand so far...
1- Fuel Pressure solenoid- delete line to acv and run a line from fuel pres. reg to lower nipple on upper intake

2- switching solenoid- has line going to acv and front of intake... just delete and plug

3- Releif solenoid- one line goes to acv and the other goes to the lower intake i think.. just delete these right. im not sure about that one

4- boost pressure solenoid- im not sure what to do with this one. i have a manual boost controller but plan on goign with a greddy profec b do i still need this one till i get the ebc..also what about the line that goes to the tid

also i wnat to remove my charcoal canister. what do i do with the check valve line that goes to the back of the intake. they t off of each other and the line that goes to the oil filler pipe

Re: boost pressure solenoid
 

This line doesn’t go to the ACV, it goes straight to the manifold, but your new route is right. Doing this may cause hot starting/idling problems.These control the ACV. If that’s coming off, these are redundant and can be removed. AFAIK, the S4 and S5 turbos use the same wastegate actuator. The boost pressure solenoid is what give the S5 its higher boost. Remove it and you’ll drop to S4 boost levels. If you’re running an EBC, it’s redundant. The “crankcase” ventilation system removes oil and water vapour from the sump. I’ve heard it shouldn’t be removed.

so i just plug that nipple on the lower intake or can i use that to tie to my fuel pressure reg or do i have to use the lower nipple on the upper intake mainfold

Some of those nipples see vacuum and boost, others don’t. To be safe feed your FPR from where ever it was fed from before.