GT30 turbo compressor housing questions/help

[griffin dai]

Hi I have a GT3076Rwg on my Saab 9000 but the compressor housing is 0.50a/r and the turbine is a 0.86 so externally looks pretty much the same as a 0.86 GT3071Rwg, but the compressor wheel is 76mm and the part numbers have it down as a GT3076R....so its definitely a 3076!! (confusing as hell to me this stuff!!)

Here's a 0.86 GT3071Rwg:


Here's mine:








But pretty much all the other 3076 ones I've seen have the 0.70 compressor housing (which I 'think' is the same as the GT35R uses?)


Would I see any gains by fitting the 0.70 compressor housing to mine or isn't it worth the effort and extra £££? Has anyone done this with theirs and did you notice much more turbo lag or any more power? I'm fitting a tubular manifold next month so was thinking of doing this housing swap at the same time.

Any help/info appreciated
Thanks in advance, Dave.

[SWR Performance]

A/R ratios make a difference, however for the compressor side the differences are not worth spending time on. The impact to the power curve is much greater at the exhaust housing.

[griffin dai]

Thanks. Yep sounds like its too much hassle for little (if any) gains. It might even make it more laggy which isn't what I'm after. I'm putting the money towards a thinner rad fan instead....cant get the tubular to fit otherwise