HP loss through automatic transmissions.

Hi Guys,

I recently tuned a Toyota Corolla 3RZ - 6466 Turbo, which I had tuned a year earlier on the same dyno. Main differences from last years setup were new higher stall torque convertor, and bigger camshafts.

Last year the car made 615whp @ 36psi on 116 Octane.

This year on more boost with bigger camshafts the most power I could squeeze out was marginally more than last year, not the increase I or the owner was expecting.

However, my injector duty cycle (same injectors, and pressure) wen up by over 20%. On the road the car feels much stronger.

I have seen cars with high stall convertors run mph's that when put into a calculator say approx 800whp, but only dyno'd mid 600s. Anybody have more experience with high stall convertors and dyno numbers?