Hi, car is jdm forester stb auto full magnex decat k+n panel filter.

I have some ongoing running probs on another thread but, whilst investigating those and messing with my piping I discovered I didn't have a restrictor pill fitted. I did many searches and came up with the consensus that it should be fitted between the compressor nipple and the T piece which goes to the wastegate and BCS, is this right???

Anyway my car had been running at 9 psi which I thought to be low but can't remember if it's always been like that. So I messed with the pipes and found them to be brittle so replaced them and also tried a makeshift restrictor pill of approx 1.3 mm dia.

Problem now is, boost pressure seems to spike a bit sometimes up to 18 psi when I first floor it but then drops right back to 11 psi which is an improvement but I still think I can afford to run more boost safely.

So, how do I get it to build, and hold a decent boost?

Does anyone know what size pill I should be running?

What boost should my car be running / whats safe?

I'm not after mega power I just want my car to be putting out what it should and keep it reliable.

Thanks to anyone who takes time to answer
Bri

 

Get to Europe - Subaru Forester Owners Forum for good Forester advice.

Not sure of the correct bore, but yes the restrictor fits between the nipple on the compressor outlet and the T-piece.

I think stock boost is 1.2 Bar (one of the S/TB or T/TB guys on the Foz forum will know), its basically the late classic WRX wagon engine (TD04, 9:1CR) you have, which is essentially the same as the same age UK turbo engine (which is slightly lower CR).

Simon

 

Get a hold of a restrictor from a subaru dealer, buy a micro drill bit set (0.6mm-1.3mm) basically drill the restrictor out by 0.05mm each time until you reach target boost.smaller hole = greater boost, larger hole = lower boost