Boost dropping - 1.7 Bar -> 1 Bar

[Vilhelm]

I get full boost at around 4000 RPM, but the boost drops slowly all the way to redline. At redline it's only boosting 1 Bar. I also get a "kick" from 4000 RPM. Nothing really happens between 3500 and 4000 even though the turbo is boosting over 1 Bar @ 3700. What can this be? There is another guy at the vwaudi-club forum that has the same problem - S2 with almost identical mods. He is running 1.2 bar though and it is dropping to 0.6 at redline.

Any suggestions?

TIA,
Vilhelm

[Vilhelm]

Anyone got any suggestions?

[topsparky]

have you done a boost leak test??

[prosty]

What WG spring are you using? Try a harder one, a 1.2 or 1.4 bar boost spring.

[Vilhelm]

yeah Jonus is gonna get a WG spring for me. I found out that my diffs don't work. I was spinning on one wheel even though both my diffs were activated. So can the diff system be leaking air and cause boost to drop up top?

[prosty]

That seems like a long shot , just check the vaccum lines from the intake, a purple plastic line going into the firewall, that's the diff. If it's broken, there's the problem (of the diffs) but see what the spring does first.