Boost Gauge Trouble

[DGK33]

recenlty installed a pivot stepping boost gauge that was purchased from another member on here and not sure if its faulty or not. i turned my boost tee all the way out so running stock boost and when accelerating hard it holds around 7psi which it should but when i change gears it spikes to about 11 or 12. it spikes everytime i change gears.why does it do this? i havnt played with my boost yet cause unaware wats goin on. any ideas much appreciated. attached a pic of the gauge aswell

[Adriano]

Usually when you wind the boost tee out the boost increases.

[James_03]

Usually when you wind the boost tee out the boost increases.

No they don't.

What you have done is correct, you wind the boost tee in (clockwise) to increase boost and anti-clockwise to decrease and fall back onto the stock actuators. If your not getting spike on standard boost then it's not the gauge or its setup, I would be thinking more about the controller itself.

[Jet 20]

Is your guages plumbed into the turbo side of the throttle body or the manifold side??

If its on the turbo side you may get a spike on the guage when you back off to shift gears because all of the sudden you have all this boost in the pipes with no where to go (cos the throttle body has shut)

so the pressure builds up quickly before it backs up to dose.

If you have a blow off valve disregard everything i just said.

just a thought..

[DGK33]

even on stock boost it spikes. and yeh you wind it clockwise for more boost. so u think i would be pretty safe turnin it up so it holds around 11psi when accelerating. i havnt fiddled with it yet but id imagine it would spike to about 1 bar+ if i wound it up a little. its not really spiking is it cause when i change gears there should be less pressure right? and nah no BOV, gettin one soon

[James_03]

Yeah I didn't read that initial post right, so your still getting this on stock boost as well. Do you have the factory bov still? Because with nothing at all you will get compressor surge which will do this when changing gears, which is why you may see a quick spike in boost.

Edited January 8, 2009 by James_03

[DGK33]

yeh thats right im gettin that spike between gears even on stock boost. so its not spiking right its just pressure thats got no where to go? so i can safely turn it up and where it holds under acceleration thats wat psi im runnin?

[RBwhatever]

If you have taken the pressure feed for your gauge from the plenum you don't see all the mumbo jumbo that happens in the piping before the TB and your gauge will also read vacuum. If you've taken the pressure feed from before the throttle body, you will see all the little boost ups and downs and little spikes etc. I wouldn't worry about it, it is normal.