stupid boost gauge question

[dhen]

OK, I realize this is a pretty stupid question, but I really don't know. Why does my boost gauge read 7 psi when I floor it, but when I take my foot off of the gas and the BOV kicks in it says 10 psi? I think this means I'm running 7 psi, but I want to make sure before I increase the boost and blow up my engine.

Thanks,

Darian

[sjbsuperman1425]

all i know is that when you take your foot off the gas the throttle closes you should have vacuum, not more boost. Where did you "T" the gauge source line into?

[dhen]

Sorry, I wasn't clear. It only goes to 10 psi for a split second, then it goes to vaccum.

Here is my setup:





Darian

[Ca_Silvia]

I thought it was a huge no-no to tap the WG line for anything? Ecspecially the BOV.

Both BOV's i ran in the past were always t'd off the back of the intake manifold. Never ran in to a problem doing it that way.

[sjbsuperman1425]

try this:

Boost Gauge - "T" into FPR vacuum source.BOV - T into manifold vacuum sourceWastegate - to IC piping or other boost source( i think thats right)

[r34 gtr]

Baller valve cover!!

[rico05]

I refrence the boost gauge from the same vac source on the back of the manifold that the FPR and butterflies reference. You do need to run a clean signal for the wastegate. I tapped the compressor outlet for a 1/8" nipple and run only the wastegate from that, and the big vac source behind the throttle body for the BOV.

[dhen]

OK, I'll play around with the way the tubing is routed. Thanks.

Baller valve cover!!

Glad you like it. Just for you, I'll let you know my secret:



Doesn't have the bragging rights that powder coating does, but it's only $6 a can...

[float_6969]

Yea, that peak you're seeing is the pressure wave building up before the BOV opens. It's not really too big of a deal actually, but you might soften it up a little.

As for the vac lines, you've got them routed a bit squirly. IDEALLY, the line for the wastegate is as short as possible. It doesn't need to see vac, so most ppl either tap the hot pipe or the compressor housing with a barbed fitting.

The BOV should be routed to the intake manifold. I use the tube right behind the throttle body on the outside of the manifold. Kind of under the throttle cable. You can also T it into the FPR line.

[bentvalves]

my ideal idea of a wastegate/actuator pressure source is as far behind the throttle plate as possible. Sourcing pressure further away from the turbo allows me to run lower wastegate duty cycles to achieve target boost, and a slightly quicker ramping torque curve results from the gate being held shut that extra few miliseconds

edit: get the BOV on its own seperate source, that is causing your 10psi spike when it blows off before it goes into vac. not that that is a problem but its just not happy there.