why the hell does my boost guage read 4 PSI when my wastegate is set at 5PSI, sometimes it does make it to five but only like 30% of the time, its done with ever since i added my intercooler

 

pressure drop my friend. the biggger the IC the more pressure drop you will get. just turn it up.

also remember u might not be hitting full boost. take it up to redline and find out.

what turbo u got on there, and what car?

 

its a 99 civic si, its a t3 turbo from some saab, but it doesnt do it all the time though, it weird?? i only have an FMU on it and it runs really good but i dont know if its safe to boost it up a bit more, because i would like for it to stay at 5PSI but i dont know if my stock fuel components can handle it

 

I hit 4 psi on a 5.5 psi wastegate due to altitude. 2600 ft hereabouts... it drops to 3 psi waaaaay up on the parkway.

Time for a digital boost controller... DIY style, of course. <g>

 

is your wastegate reading pressure before the ic? it should read intake manifold pressure, same place your boost gague reads from.