I have a .42/.63 garret turbo.

can i change the cold side housing to something bigger? is it that simple or do I need a new propellor?

 

The backplate, compressor impeller, and housing all need to match, whichever you decide. If that is a saab OEM turbocharger, not worth the money.

 

TheShodan is right, generally you're best off selling the thing and buy a new turbo. It will have ALL new parts, the better stg3 turbine, better castings, etc. If you're planning on making much power with your vitara build, you'll want more than that 25yr old turbo can be [cost effectively] upgraded to.

 

its not a saab turbo its a fairly new garret unit.

I got it tuned today.

maxed out my injectors at 250hp around 14-15 psi.

the turbo is plenty big for my daily driver. it definatley spools up quick!