With all associated mods - whats the max BHP you can get from the VF28 turbos fitted to the STi5??
Any help appreciated
Marv

 

Depends on rollers and luck. The highest has been 377 BHP I believe. Not sure how easy that would be to reproduce. It should deliver 310-340 BHP depending on the dyno used.

If you had headers, 3" exhaust, good induction, inlet pipe, ported turbine housing, FMIC, water/methanol injection, ECU remap then you stand the best chance of extracting all that is possible.

 

Cheers John - have got or will have most of what you mention shortly. Was thinking about changing the turbo for something bigger (partly coz I think I'm using oil through mine - or so I'm told - can this happen?)
Thanks for your help m8
Marvin

 

What makes you think you are using oil through the turbo?
I got 377bhp with a minor mod to the VF28 but that was on the edge of what it could do and every supporting mod I could think of was done and done properly. On another car with quite a few mods it was only in the 340bhp bracket.

 

harvey - thanks for your post m8.
I bought my STi5 when it had done 16k miles (it's now done 44k). Throughout that time I have always had to top up the oil, approx 5 litres between the 7500 mile services. There are no visible leaks, there is no smoke under normal/fast running and very little when I really 'boot it'. Someone suggested to me that it could be the turbo that is burning it off - sounds logical - but how can you check? Its running sweet, 300 BHP on the rollers.
Any advice?
Cheers
Marv

 

Some cars go through oil and if there is no visible sign of it being used I would just accept it as a feature of that engine. If it aint broke don't fix it. Certainly I would not start looking to replace a turbo on speculation that could be the cause of 2/3ds litre per 1,000mls.
You could check the crankcase breather located near #3 cylinder below the top mount I.C. and also each cam cover breather. You could also lead these three pipes to a PROPER catch tank.
My current engine with Cosworth pistons can use around 1 litre per 1,000 mls but i do not regard it as a problem as it has done it since the rebuild, 30k mls ago approx.
Go to a steep down hill and get 6k + rpm in 5th or 4th and foot off on the over run. Let revs drop with no braking 'til say 2k rpm and floor it. If no BLUE smoke then no problems. Apuff of black may be normal.

 

Thanks again harvey - I'll give it a whirl