What external wastegate turbine housings are offered for the HX40? And where can I get one? Ideally Im leaning twards the 14cm if available. Also, Is it posible to machine a HX35 12 cm housing to accept a HX40 wheel?

 

I think the 16cm is the smallest available for ANY HX40 in stock form. I have seen that some guys will machine a 12 or 14cm to take the 40 exhaust wheel, but that doesnt leave much "meat" on the housing for heat dissipation. It's a trade off- do you want higher air flow, or quick spooling? It takes $$$$ to get both, but it is possible.

Daniel

 

Id sacrifice some spool to get mid and high end power. This setup is on my 4 cyl turbo car with a .55 a/r turbine housing. Its a animal out of the hole easily spinning the slicks in gears 1-2, but it falls off when the boost is up due to back pressure. So this 12cm turbine housing I have I can just chuck it up in the mill or lathe and open it up to accept the 40 wheel?

 

The title of your thread mentions Pro40. If you're talking about a Super40, they come with a 16cm wastegated housing. Stock 40's come with 14wg, 16wg, 18wg, 19 and 21 non-gated housings. The 14 and 16's being RARE. Also some come with the bigger T4 flange instead of our stock T3 mounting flange.

I've heard of guys hogging out the bigger 16 and 18cm h1c exhaust housings, but not the 12. It's not a big deal, pullers hog out housings all the time to fit massive turbine wheels. If you cut through it, just weld it back up. Take some measurements and see how much you need to remove.

I'm with Daniel though, I'd go no smaller than a 16cm h1c housing. A hx40 with a 12cm hx35 housing would be a pending disaster.