Dude, if your gonna go the full hog then best you buy yourself a new bigger turbo to go along withcams/headers/etc.

The vf34 is only designed to flow so much air through its 47.9mm comp wheel (same diameter as a vf35).
Adding the p20 exhaust housing just increases the rated flow to that of vf22 specs... ~480cfm @ 18psi.

a simple vf34-p20 is a cheap and simple turbo upgrade. It gives you increase in top end performance, without sacrificing too much bottom end.
If you want to keep your vf34 turbo - then may i suggest to upgrade the comp wheel to that of a PE1820 spec.

the PE1820 uses a dual BB catridge, and the turbo is essentially a vf34-p20 with a wheel upgrade...and a $2000 pricetag.

Product: PE1820F
Manufacturer: Power Enterprise
Turbine Specifications:
Housing A/R: P20Bore Size: 25.0mmTurbine Wheel Blades: 11
Turbine Wheel Inducer: 53.0mm
Turbine Wheel Exducer: 48.0mm
Compressor Specifications:
Compressor Wheel Blades: 6+6
Compressor Wheel Inducer: 52.5mm
Compressor Wheel Exducer: 70.0mm
Center Section Bearing: Dual ball bearing

VF-22


PE1820


This upgraded wheel transform the turbo to push out 630cfm @ 1 bar. (manufacturer rating).
I have heard that Adelaide Turbo Services (A.T.S) can upgrade your turbo for under $400.

So basically, if your gonna do it - then do it properly. It means that you wont have to boost your turbo high to acheive good power.

I didnt go this route coz its not what im aiming for. I'm keeping the stock 550cc injectors, and will push boost till they start running out. Whatever power/torque that makes then so be it. But the turbo defintaly has the potential to acheive some higher numbers if your prepared to push it.

With the added water/meth - think of it as essentially another injector squirting higher octane fuel. So with the combined injectors and meth spray - it will give me some more room to squeeze some more boost into the engine and dial some more timing into it, and see where it goes...