He has corrected his mis-statement in the first post and actually posted some weights.
Looks like he got his information from John Kilgore's site here:
Which is good information and John Kilgore is one fo the innovators on the Th400, however I'm looking for some actual data that Dave has, not what he can find online.
He still hasn't answered what the ET difference would be or the total rotating weight.
His quoted weights are wrong, the Th400 does not weigh 166 lbs less than a 4L80E..., The 4L80E is not THAT heavy...
The difference in total rotating weight between a TH350 and 400 is 10.4 lbs.
The difference in the direct drum is less than 2 lbs.
There is no set HP consumption number for the difference, yes a Th400 will consume more HP under acceleration or decel of the parts, but not at steady speed...
The amount consumed is not going to be "24 HP" it will vary by the rate of acceleration, not the torque input.
You cannot compare two transmission based off of a different torque converter, they both use interchangeable torque converters but for the purposes of this comparison, the converter has no effect.
Notice in his original post:
Originally Posted by Larger Dave
It has a lot of rotating mass that has to come to dead stop and reverse it's rotational upon each shift. That consumes power; for this reason the TH400 has more parasitic drag than the TH350.
he did not mention the parasitic drag as being the converter but the larger mass of the TH400, so which is it, the converter or the transmission.
If we back to back tested a Th350 vs. a 400 using the same converter, or a hub drive to eliminate converter variables, what would the ET difference be..?
I can say this much,
on all the cars I've dealt with, I've never seen any difference in ET (usually an "upgrade" to a Th400, that according to all the internet experts would result in an ET loss because of gearing, rotating mass, overall weight, there has never been any real measurable loss.