Vacuum Diagrams(Stock, Simplified Sequential, Non-sequential, Single Turbo
Thread Starter
Joined: Oct 2005
Posts: 2,294
Likes: 24
From: San Jose
Honestly if you plan on staying twins dont go non-seq. if you want simple save up and go single youll thank yourself down the line. If you would like to help the simplified seq. and make it a little easier to trouble shoot if you do have problems then you could do the simplified seq. system. Help reduce the amount of parts that could fail, makes the lines easier. It does remove all the emisions stuff and keeps all the solenoids for the seq. system to work properly.
Chris
Chris
Junior Member
Joined: Apr 2008
Posts: 18
Likes: 0
From: Jacksonville, NC
BUMP
i was wondering with the diagram below, is that seriously all the hoses you need!?
if it is, i dont understand why everybody doesnt go single then?
i was wondering with the diagram below, is that seriously all the hoses you need!?
if it is, i dont understand why everybody doesnt go single then?
Last edited by Rotorsex; Apr 14, 2009 at 08:14 PM. Reason: bad picture
^ that is a nonsequential diagram, not a single turbo diagram.
If anything, the diagram could be simpler. I don't agree with keeping the fuel pressure regulator control solenoid valve. you can run the stock FPR right to a vacuum/boost source. that solenoid is mostly to prevent vapor lock, which simply doesn't happen.
as you can see, it only comes on when fuel temps are over 80 C (which rarely/never happens, ask someone who has hooked up their fuel temp sensor to their water temp sensor connector by accident). The car also has to be left in Neutral for the solenoid to engage. I know it says "except neutral" but if you have ever looked at computer logic diagrams (that is an AND gate), that little circle thing next to the D means there is an inverter there which essentially changes the signal. anyway the solenoid is useless because it never really turns on if you examine the logic circuit, that's all you need to know. just take it out.
the PCV valve is also unnecessary. the filler pipe vent can be routed to before the turbo inlet or to a vented catch can. a PCV valve only draws crankcase vapors out under low engine loads for emissions purposes. Under high load the vapors escape on their own without a PCV valve, and in fact under high load the PCV valve closes. I don't know why the charge relief valve is still there either. if you are premixing the two dark blue lines can go, they are for the OMP.
One thing people do that I don't agree with is removing the TB coolant hose and fast idle system. all that does is make the car idle like crap on cold start, just to save a small amount of plumbing and have a negligible decrease in intake temps.
If anything, the diagram could be simpler. I don't agree with keeping the fuel pressure regulator control solenoid valve. you can run the stock FPR right to a vacuum/boost source. that solenoid is mostly to prevent vapor lock, which simply doesn't happen.
as you can see, it only comes on when fuel temps are over 80 C (which rarely/never happens, ask someone who has hooked up their fuel temp sensor to their water temp sensor connector by accident). The car also has to be left in Neutral for the solenoid to engage. I know it says "except neutral" but if you have ever looked at computer logic diagrams (that is an AND gate), that little circle thing next to the D means there is an inverter there which essentially changes the signal. anyway the solenoid is useless because it never really turns on if you examine the logic circuit, that's all you need to know. just take it out.
the PCV valve is also unnecessary. the filler pipe vent can be routed to before the turbo inlet or to a vented catch can. a PCV valve only draws crankcase vapors out under low engine loads for emissions purposes. Under high load the vapors escape on their own without a PCV valve, and in fact under high load the PCV valve closes. I don't know why the charge relief valve is still there either. if you are premixing the two dark blue lines can go, they are for the OMP.
One thing people do that I don't agree with is removing the TB coolant hose and fast idle system. all that does is make the car idle like crap on cold start, just to save a small amount of plumbing and have a negligible decrease in intake temps.
Thanks for the awesome post. I had a quick question. When doing simplified sequential, Do you need any resistors for the solenoids that you remove such as the EGR? I remember reading that if you put resistors in between this will stop check engine codes from coming up, but wasn’t sure if this just applied to going non sequential or not. I just want to be sure.
Thanks
Steve
Thanks
Steve
hey chris, thanks for posting this! i'll need it when i get to install those bnr's and rob baily's solenoids that i got from you! i know they were already in a sticky but it's nice to see them all together.
Senior Member
Joined: Oct 2002
Posts: 526
Likes: 4
From: Atlanta
The BOV releases pressure from the entire turbo system when you let off the throttle so as not to create a sudden (and over time harmful) backpressure against the turbos.
The CRV releases any airflow created by the secondary turbo while the primary turbo is operating (before the secondary turbo is called on to kick in -- around 4500 RPM).
The BOV releases pressure from the entire turbo system when you let off the throttle so as not to create a sudden (and over time harmful) backpressure against the turbos.
The BOV releases pressure from the entire turbo system when you let off the throttle so as not to create a sudden (and over time harmful) backpressure against the turbos.
If that's the case, whats the best way of plugging that hole?
