OK here's my question... If i'm to replace the standard small mitsubishi turbo with a bigger one, what should i go for?

Spec:

* Subaru Impreza Turbo MY98, 211HP standard spec
* K&N induction kit
* Scorpion catless exhaust front to back
* Blow-off valve
* Chipped

Should have +/- 260 BHP, but boost is very irregular throughout the rev-range.

If i take 1 step up, i could go for the VF28 (from 1998 STi V5). This turbo kicks in with max boost around 3200 RPM and gives full boost till 7000.

If i take another step up, i could go for the VF23 or VF30 who kick in at 3700 RPM, but have a bigger housing, so more air at equal boost, but more turbo lag...

If i were to run the VF28 at say 1.4 Bar (20.3PSI), how much BHP would that give me (ballpark)? and with the VF23/30, i suppose i could have the same BHPs at lower boost, if so, what what boost and what do i get with those huge turbos at 1.4 Bar (20.3PSI)

Is there anything else i should take into consideration before upgrading?

Thanks for your very intelligent answers

 

Well there is a UK car out there - with the smaller VF housing - P18 - running 340bhp + at 1.2bar

It's not the boost - but the amount of air that can be flowed.

The person that I am aware of with the broadest experience of lots of different hybrids - TD as well as VF is Mark - posts on here as R19KET - try him.

Trout

 

20 PSI on most of those would get a bit hottish on intake temperatures with the standard top mount.

VF hybrid from Mark at 20 PSI on uprated top mount - intake temp 30 + ambient at most.

 

Simon

I would say which turbo you get depends on your application.

For everyday driving / rally get a smaller one, for track use, where you are always on boost, get a bigger one.

Ask for the rating: some bigger turbine cant be run at above 1.2/1.4 bars although they flow a lot more air. I have been in a Bozz Speed Evo 6 with an HKS 3037 turbine and was very disappointed.

 

Simon,

check the For Sale section

Trout