Pls could someone tell me what the boost pressure should be on the following -

Standard STi2?

Standard STi2 + T75 twin downpipe (no cat) + T75 backbox?

Thanks,

 

bttt

 

STi2 std pressure is 13psi, it "will" possibly peak a little higher with the exhaust change. that assumes that all the boost control pipework is original and intact (including restrictor). Uses the larger TD05 turbo hence the lower value compared to later cars.

bob

 

Thanks - I'm getting 14.5 peak and around 13 held - would this suggest the ecu has been fiddled with?

 

No, it suggests the loss of the cat allows the turbo to spin up more freely due to improve exhaust flow.

This is normal.

Paul

 

After securing the intercooler unit (it was loose) I am now getting about 16.5psi peak and 14psi held

Surely this is much higher than standard and points to an ecu fiddle of some sort.

The trouble is the prevouis owner in Japan has bolted a kick plate across where the ecu sits so I have no way of checking without removing it - something I wont bother doing if it looks like the ecu has been fiddled with already

How high do you think is safe take it 18, 20 psi?

It has had samco coolent kit