So Im curious how to set up BOV and wastegate. Its my understanding the wastegate is what sets the boost pressure and protects the motor. The BOV is supposed to protect the turbo from sudden stop when the throttle body is closed during boost. Correct?
I know the wastegate is set by a spring and the BOV has a screw to set pressure. How are they supposed to relate to each other? For example, if the WG is at 10lbs what should the BOV be at? Greater, equal, lower ( I dont think so)? Does it matter? My thinking is the turbo may be able to handle more back pressure than the motor and setting the BOV higher than the WG may lead to less spool up time. How does one test these settings? Can I just give them some compressed air on a gauge?
Im not having any issues with my setup, just curiousity...
Thanks
Full Version: Turbo Question
The BOV uses the boost pressure to keep it closed under boost while the throttle plate is open. When the throttle plate is closed, the BOV will open, if boost is present. There are 2 ports on the BOV, top and bottom. The bottom one gets plumbed into the intake between the turbo and the throttle plate. The top one goes to the intake manifold, after the throttle plate. They cancel each other out when the throttle is open. Close the throttle, and the remaining boost in the system pushes up the diaphram in the BOV, which releases the pressure.
My TIAL BOV has one line and that goes to manifold pressure.
The BOV needs adjusting according to your vacuum pressure. A weak spring and high manifold vacuum will cause it to stay open or come open too soon. Too stiff a spring or low vacuum and it will not open.
The wastgate has two ports one goes to the turbo and the other is used for boost controllers. It gets it's boost signal from the turbo itself.
To answer your question in simple terms.. There is no relationship bewteen the two. One relieves boost pressure one relieves back pressure.
You can run a car at low boost without a BOV.
edit to add..
Only relationship would be the BOV reducing/eliminating back pressure on the blades giving precise dumps by the wastegate.
The BOV needs adjusting according to your vacuum pressure. A weak spring and high manifold vacuum will cause it to stay open or come open too soon. Too stiff a spring or low vacuum and it will not open.
The wastgate has two ports one goes to the turbo and the other is used for boost controllers. It gets it's boost signal from the turbo itself.
To answer your question in simple terms.. There is no relationship bewteen the two. One relieves boost pressure one relieves back pressure.
You can run a car at low boost without a BOV.
edit to add..
Only relationship would be the BOV reducing/eliminating back pressure on the blades giving precise dumps by the wastegate.
QUOTE (Tripod @ Jan 22 2009, 08:09 PM) 
The BOV uses the boost pressure to keep it closed under boost while the throttle plate is open. When the throttle plate is closed, the BOV will open, if boost is present. There are 2 ports on the BOV, top and bottom. The bottom one gets plumbed into the intake between the turbo and the throttle plate. The top one goes to the intake manifold, after the throttle plate. They cancel each other out when the throttle is open. Close the throttle, and the remaining boost in the system pushes up the diaphram in the BOV, which releases the pressure.
Its been awhile since I set mine up. Setting the spring pressure on the BOV was detemined how much vaccum my motor had at idle. I dont think it has any connection to what your wastegate is set at.
Plus I thought the vacccum is what opened the BOV to exhaust the boost pressure trapped between the turbo and throttle plate
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