This turbo is built on the well respected T4Z frame turbo. Most people are familiar with this configuration as a "T67" or a "GT37R", both poor names that didn't really describe this turbo well at all. After all a T4Z is not a GT37, and calling out inducer diameter is sooo " 80's turbonetics" that I have to get my rubics cube out whenever I say it.
So now that you know that GT37R were really T4Z turbos, you likely have a better idea what this turbo is about. Our version ditches the "t67" compressor wheel. That wheel was a 63 trim wheel that really left LOTS on the table when it came to high boost performance, giving only a max PR of 3.4:1 even at it's highest speed line of 120krpm. The HTA easily sustains PR in excess of 4.5:1 making 45psi or more boost pressures possible, consistent and dependable.

The compressor housing is the familiar T4S cover with 4" Anti-Surge ported inlet and 2.5" outlet. The default recommended turbine housing is the .82 AR T31 style with it's compact 2.5" 4 bolt outlet, we stock the gaskets and flanges to fit this flange. Optional housings are the GT35 style with its 3" 4-bolt outlet, or the 3" vband outlet style in .82 or 1.06 A/R sizes. Also T4 flanged housing in open and divided in all standard A/R sizes, just ask!