What happens when a turbo produces too much boost??

Is it a good thing or will it hinder performance?

This is not really impreza related but thought i'd ask on here as i know i'll get a good answer and quick response.

I have a ko4 turbo as used in the LCR/Audi TT/S3 and it is mapped for 1.5 bar (21psi) This is about the limits of the turbo.

1 person i know is boosting at 28-30 psi and not going into limp mode but is this a good thing or will it hinder performance? I say that in the fact the heat created from a small turbo at 30psi will be far more excessive than the heat created at 20psi?

Will his extra boost give him more performance??

Thanks

 

Hi mitchy, i bet this persons car goes well! at least until it goes bang. imho 30 psi is far too high for a smallish turbo. A turbo will produce less heat at lower pressures because it is not working as hard, the higher the boost the harder the turbo and the whole running gear is working. The bearings of the turbo will be the first to go. If you want to run high boost choose a turbo that will give you it without over working.

 

the perfect fuel air ratio is 14:1 and a turbo allows to cram lots of air and fuel into a small space for a bigger bang!

If the rest of the setup cannot deliver at the same rate then you will loose performance (injectors, fuel pump etc) as you will not be acheiving the optimum 14:1.

If they can match the extra air being pumped in with more fuel then you would get more power however you will most probably be operating outside the manufacturers operating limits.....melt down

just an amatuers take on this, I'm sure someone else will be along with the facts