[Sirrotica]

Originally Posted by ta man

I would think a slower et like a 11 to 13 second car would actually show the parasitic losses more than a 10 second or quicker car.

Direct quote from Jakes Performance:

he 4L80E will theoretically consume more HP than a 4L60E or other lighter duty transmission. It has a positive displacement pump as opposed to a variable displacement, it is heavier, has more rotating mass, more clutch drag, and on the surface would seem to “eat” HP. The biggest loss would seem to come from the heavier rotating mass. However what is widely misunderstood is that yes it’s heavier, but that alone doesn’t cause more power loss. Remember an object in motion tends to stay in motion unless acted upon by another force. So unless there is more friction involved, a heavier rotating mass doesn’t take any more HP to maintain the same speed as a much lighter mass. It DOES take more power to accelerate or decelerate the heavier mass. So what this means to the average enthusiast is the faster your car, the more power the transmission will consume. This applies to all transmissions. Power loss through the transmission will increase the faster you accelerate it. Our testing has shown that you will not see any significant power loss in a 11, 12 or 13 second combination. They simply aren’t accelerating fast enough that the rotating mass really comes into play. As you get into the low 10 second ¼ mile times, you may start to see some differences between a lightweight transmission and a heavier one. The thing to remember is, typically the lighter duty transmissions become a maintenance item at these power levels. More frequent rebuilds and failures. So for a small loss of power often equating to less than .05 second in Elapsed Time in the ¼ mile, you gain reliability. Unless you are racing for a record attempt where hundredths of a second are crucial, reliability is usually a more important factor.

I'm sure Jake has plenty of experience with these transmissions to back up his statements.