Boost gauge question at full boost...and bov question
 

ok quick question, dont know if its normal, but my boost gauge (defi D) needle shakes rapidly at 20psi (im runnin MBC) at full boost, is this normal that it shakes like its feathering usually at 5th gear. and also another funny thing is...i've noticed this on my forge and HKS SSQ (VTA), when i floor it in 5th and i let off, the bov opens late or slow or something, its kinda dangerous cuz i let off, and the car still pulls for about 1 second and then the bov lets off, in the HKS SSQ case, it lets off late and really slow, the whistle lasts about 3 seconds, instead of the usual 1 second or so.

bump

You might have a leak in a hose.. and does the gauge look like it does when yu are going like 30 in 5th and floor it.. needle shapes rappidly..?..Did you try backing off on the boost?

kinked hose somewhere

If the car is still pulling after you let off the throttle then the throttle plate is not shutting.... this would also cause the late reaction in the BOV since the BOV don't open until there is vacuum in the intake manifold from the throttle plate shutting. You need to check your throttle cable, and the pedal itself to make sure nothing is making it stick.

Keith

i adjusted my throttle cable and left it a small bit of slack. But these problems only occur in 5th gear at WOT. As for teh Boost gauge issue, no it doesnt shape or feather when in any other gear, only 5th at WOT, it shakes and the BOV issue comes up, i am switching to the MR DV this week so i'll see how that works out, but the boost gauge issue still worries me how it feathers, is it supposed to be solid at 20psi? or would it still feather a bit?