Hello,

I have been using search for the last few days trying to find my answer and I can't find it. When comparing a 4L60E to a 4L80E, a lot of people mention parasitic loss, but I haven't been able to find how much more an 80E consumes than a 60E. Lets say an LS1 is making 450 crank HP and they both have a 3000RPM converter. If you were to hook up a 60E vs an 80E how much difference would it make for RWHP and RWTQ?

Thank you.
Kevin C

 

I had an 4l80-e in my monte carlo to start out with and the people I talked to said it is about a thirty horsepower loss. It is almost the same loss as a th-400 it is essentially the same trans only with an overdrive unit added in the front and electronic controls. I swapped to a 4l60-e later and found it to be much more responsive off the light and around town driving.

 

the 4L80 has a 2.48 first gear ratio. the 4L60 has 3.06 jk

 

Just to put what John said into a little better perspective,
1st Gear-----Rear Axle-------Final Drive
3.06-----x-----2.73-----=-----8.35
3.06-----x-----3.08-----=-----9.42
3.06-----x-----3.42-----=----10.47
3.06-----x-----3.73-----=----11.41

2.48-----x-----2.73-----=-----6.77
2.48-----x-----3.08-----=-----7.64
2.48-----x-----3.42-----=-----8.48
2.48-----x-----3.73-----=-----9.25

Assuming the 4L80 and 4L60 had the same parasitic losses, you'd have to run a 3.42 in the 4L80 to get the same final drive ratio as the 2.73 in the 4L60

I'm still looking for any place other than transmissioncenter.net that sells the 4L80 with 2.75 1st gear and 1.57 second gear ratios...

 

Is the power loss a percentage of power made or is it a set # power loss?

Thanks,
Kevin C

 

For the most part, given the limited operating range (rpms) of the transmission, the power loss is a percentage from what I've heard.

 

What would the percentages of power loss be in comparing the 2 transmissions?

Thanks again,
Kevin C

 

I've been searching all over the place and can't find anyplace (other than 01WS6/tamu) that mentions the parasitic loss from the 4L80-E.
So his estimate of 30% is all I have to go by for the moment