Please help turbocharge my Volvo 1800

[Micahwc]

In that fifth picture from the end, Is that a keg in the back of your car?

For turbo sizing, I would guess that any turbo out of a 3.0 liter car would be about right. Since you are going to have to make your manifold custom, you could use just about any turbo you could find. The only 3.0 single turbo I can think of for possible turbo donors is the 87-91 turbo supra (or any of its bolt on upgrades). Every other 3.0 or 3.5 I can think of is twin turbo. You could look into the single turbo upgrades for any of these twin turbo cars though, mk4 supra, 3000gt/gto, 300zx, etc. All of these cars have large single turbo conversions which are common, as well as 3.0 liter engines. You would just need a turbo flange to weld onto your custom turbo manifold.

I know of one company that sells turbo flanges for custom turbo manifolds, which sells one for the ct-26 turbo out of a mk3 supra. It actually sells them for usage on dodge neons.

If you did want to try a twin turbo set up, the turbo's for the USDM 3000GT (8G's I think) are small. You could run each 3-1 header pipe into one turbo.