GearCity 1.18 Progress

[foreverska]

then peter off again at high revs.

That depends on the turbo sizing. Many OEMs do it this way but if I stuck a GT35 on my 1600cc air cooled vw motor it would lag a LOT and still be pulling hard when the valves start to float.

Same turbo on my 2.5L might behave closer to what you describe. Definitely so with a head spacer and Ti valvetrain.

Point is, without knowing the turbine size it's really a crapshoot as to how it will ultimately perform.