right before reaching full boost the needle starts fluttering back and forth. Usually i just i take the foot off the pedal, im afraid of boost spike. What do u guys see on your gauges when u reach full boost?

 

i have a shitty pos second hand boost gauge i got for free. and it is always off by 1psi. but it doesnt do what you described. sometimes it wiggles a little at idle in vacuum, thats it.

 

are you running a boost controller?

 

I have a greddy 52mm I dunno if its reading 100% correct, but it definatly doesn't wiggle at all, its very steady. It was also used, and I had to fabricate the harness that goes to the black box where the vacum line plugs in (that was fun).

 

no boost controler. i have a deltagate wg with a 7lb spring. Just to reiterate what im seeing on the gauge, right before the gauge needle hits .5bar it starts vibrating back and forth.

what do u guys see on your gauge when your approaching and when u hit full boost?

 

Probably that POS deltagate.
Check over all your vacuum lines. Try to get a dedicated line for the boost gauge.