Seems to be a complete absence of technical information on the internet for this, even IHI don't publish anything and they make it! Anyone know the safe boost limit for this turbo? My PPP ECU currently has it at 1.147 bar.

On another note, has anyone seen any low end torque benefit by advancing the AVCS, low to med rpm for med-heavy load? Seen some data around indicating that one can nearly double the gas density in the cylinders at low-med RPM. Presumably this needs the ignition to be retarded and AFR enrichment if the air density is going up in the cylinders...

 

if you do a search for vf39 turbo psi a lot of results mention anything from 14.5psi to 18psi

not sure if that helps.

 

Thanks Shailin, however I've already got those numbers. As you say, somewhere in the '14.5 - 18psi' range isn't really useful.

Bizarre that it's the standard turbo on the UK STI8 but no-one knows.

 

Try NASIOC for info on the VF39 -its a VF35 on UK STis.
Safe boost will be IRO 1.4 - 1.5 bar.

Nick

 

Subaru Turbo List - NASIOC

It is std fit on USDM cars but not UK - Essentially it is the same as the VF43 though so 1.4 - 1.5.

Yes. There is a lot to be gained from experimenting with the AVCS and comparing the results on the dyno.

 

Thank you gentlemen. I didn't realise it's the VF35 for non USDM. Surprised at how conservative Prodrive are with the boost. I get the impression I could retune the car safely to 1.4 and get a 22% hike in boost. Time to get the LC1 out....