What kind of turbos came with this flange?...and what cars can I find them on. This is a Holset H2 turbo, but people tell me that it will bolt to a sy/ty manifold. St/Ty's are not the most common cars around, are there any other cars with a flange like this?

T3

Should be the same basic flange as a T04... but I'd double check the dimentions since the Holset turbos used 2 basic flange dimentions, one that will match and the other that won't.

It's not a t4 flange, t4 flanges are more square where the t3 ones are rectangular

T4:



T3:



EDIT: well that didn't work so just copy and paste the url and they work

The attached picture is a drawing of the generic T3 layout. There are others but 90% of the ones that I've seen are laid out like that and the other 10% have been the GM only 3 bolt flanges. I believe that a flange like in your picture was used on some Mercedes diesels, but I’ve never seen one in person.

Garret T04, T06 and T08 flanges all have twin inlets, and I’ve found that how squared off really changes from turbine housing to housing.

I would be pretty surprised if a turbo the size of an H2 had an inlet the same size as a T3. But like I already said, Holset lists at least 2 inlet flanges for all their turbos, a big and a small. Why don’t you just measure what you’ve got and see what it matches. Some of the small holset turbine inlets are within 1 mm of the T3, and others are fairly close to the TO4’s.