Info on overboost/whistling needed
 

sti v5 ra my99 completely standard has hit over boost twice now (only in 1st gear)have i a prob with wastegate control ?
also should it have a forge d/valve as standard

and there is a whistling noise on full boost which sounds like blowing over a bottle
and when it stops at juctions after giving it some stick its idle rises/falls (very nearly stalls)for about 5 secs then its fine again

other than faults above it drives perfect
k/L showing no det at all(green all the time)

hopefully it is a case of clean wastegate soleniod/iscv
reset ecu (hav'nt read codes yet)

please advise!!!!!!!!!

bttt

Forge dunp valve - don't beleive this is standard - presmable its a VTA type - if so this is likely to be the cause of your near stalls/stalls at junctions:

As the valve is after the MAF sensor when you shut the throttle, a bunch of air thats metered is dumped from the system making the mixture run momentarily very rich - I had the same problem on mine.

It can also be caused by O2 sensor / sticking idle contol valve.

Over boost is not likely to be a dirt solenoid as this usually manifests itself by sticking closed and giving base boost only - don't count it out though.

If you have a 2 port solenoid - a partially blocked actuator line restrictor ( the tiny brass jobby inside the hose) can cause the exact symptom you mention.

Can't comment on the noise you have on full boost - mine does make a very audiable whistle on full boost and I did have a 900 T16 with a Garrett T3 that sounded exactly like a hooting owl at +17 psi. - Could well be the normal noise - just try eliminating all other possibilites (hose leaks / disconnections etc etc)

if its a atmosperic dump valve and its whistling at high boost sound like it could be leaking

cheers guys

got chance to look at it today found a turdy eco valve lurking under the coil pack that is prob with the whistle as it had lossened from its locking nut(now in the bin where it belongs)

read codes from dash and came back as 23 (maf) so iv just ordered it so hopefully it will be right tomorrow
will check wastegate pipe aswell

cheers karl