Replacement transmission

[eschaider]

Originally Posted by Grubby

I think you will need more gear with a TKX. I have a moderate built 427 with 600 horsepower and 3:54 rear. ERA recommends 3.31 or 3.54 with their builds.

For what it is worth, I would try to work a deal on the Richmond trans noted above.

John

I think our seat of the pants dyno is significantly impacted by low-speed engine torque, John. If the engine was built for bottom end and midrange torque, it should be OK. On the other hand, if it was built for midrange and top-end, maybe not so much.

I should have elaborated on that a bit more. Typically, if you have a problem with smooth, predictable engine behavior below 2000 rpm, the engine was probably built as a midrange / top-end performer, and you are spot on; it will take a taller gear to get the car to perform the way our seat of the pants dyno would prefer. On the other hand, if you have a robust low-speed torque curve, the engine won't even break a sweat.

PD-blown engines, whether using Screw or Eaton TVS rotors, would be examples of engines with robust low-speed torque. N/A engines with frisky cams would be examples of engines at the other end of the spectrum with robust midrange and top-end power but lacking in low-speed torque.

Strokers with moderate camming will fit the middle ground very nicely and provide you with good low-speed power, although you might prefer a R&P that looks more like a 3.08 or so.