I am having my Unichip fitted next week and am after some definative advise regarding what level of boost to run, safely.

Before anyone starts on the "You must go for a LINK instead" etc etc . I have used the Unichip on other cars for the last 3-4 years I am happy with the person who is mapping it................ So its not an option.

I have a MY99, STI 5 Type R with

Scoobysport Downpipe
Blitz Nur Spec R Full System
Water Injection (To be mapped with the Unichip)
Aftermarket Panel Air Filter
Optimax and NF

I wasn't planning to get the boost raised over the standard setting(17psi peak)as I thought that I would be happy with the fact that the introduction of the EBC with the Unichip will provide me with enough through a more consistant level of boost throughout all the gears. Say peaking at 17 and then holding 15 etc. Rather than the peak and drop, and variations in the different gears.

Recent posts on the list have seemed to outline being able to run 20psi or more on an STI engine safely?? Is this correct???
If so I might reconsider my plans


Advice would be greatly appreciated

Nothing wrong with the Unichip :)

A few considerations:

1. Clutch/gearbox
My UK clutch/gearbox have been OK on short testing up to 23 PSI. Have been running 20 PSI for a while with no issues so far, but many say it is only a matter of time. There is now a viable, streetable tough gearbox option but it would be £2000-3000 built and installed.

2. Detonation
Your WI will help, as would a FMIC. Any turbo when pushed hard will pump out hot air and create a lot of exhaust back pressure, so changing the turbo would help.

3. Strength of internals
Probably not xy PSI and it will go pop, but a lower mean time between failure the higher you push up the boost. 20 PSI is not daft as long as it is not detting, exhaust gas temps are sensible etc.