boost needle "flicking".... is this normal?

[moo_r32]

i have a 93 32gts-t, and i noticed the other night that when i take my foot off the gas the needle on my autometre boost gauge flicks from my stock 11-12psi up to about 16-17psi......is this normal? is it just the time b4 the blowoff valve kicks in.?

[DJ984]

bleeder valve and boost spike?...

I have no idea to be honest but that's all i can think of man...

[Craved]

dont think it would be anything to do with the BOV, since you would be getting your reading from the plenum, and the BOV is on the other side of the throttle body! does it stay up there or just go up then drop off to vacuum?

[Intensevil]

Could just be a kinked cable

[knore]

If you have a bleed valve then this is pretty common,

does it happen when you floor it ? like your on max boost for a few seconds then it goes PSSSHSHH up to 17psi or whatever

cos realistically it cant go up to 17psi, stock turbos can only push a max of about 14

[moo_r32]

yes craved it does, it kinda feels like as soon as i come off throttle there is a micro second where the boost biulds up thes ptchhhhhhh its back down to 0, could it be something to do with the waste gate or sumptn, im going backpacking for a month so she will be resting for a while and getting dyno tuned when i return.

is 11-12psi stock boost?

[moo_r32]

forgot to say that i have attatched the boost guage to the hose at the top of engine at the back near the firewall, should i try sumwhere elce

[Craved]

7psi is stock boost so there is something controlling your boost!

have you still got the standard boost guage connected? if so does that peak as well?

[Elithrar]

10psi is the stock boost on an RB20DET.

[Craved]

fair enough, didn't realise that! i stand corrected Elithrar! so that would suggest that maybe just the exhaust etc is putting it up more with better flow! still doesn't explain a boost increase on engine side of the throttle body.

[DJ984]

yeah, 10PSI is stock on '32s and a 3" cat-back will make it spike to 12 (like mine....)