Drivetrain horsepower loss
GM
PG 18 hp
TH-350 36 hp
TH-400 44 hp
FORD
C 6 55-60 hp
C 4 28 hp
FMX 25 hp
Chrysler
A904 25 hp
727 45 hp
Absolute numbers are kinda misleading. I mean, I can spin the input shaft of a 904 at say 60rpm, and I don't have 25 hp in my left arm. But say you figured out a way to to have that 904 all tanked up, on the bench, just like it would be in a chassis, I bet I could still spin it up.And I still don't have 25 hp in my left arm, or my right arm.
But lets say you don't like my thinking.
So let's say you have a /6-904 in your 73 Dart.A slanty is NET-rated at about 140hp, right;probably at somewhere between 3000 to 4000 rpm.Let's arbitrarily gross it up to 180 dyno hp.
So just off idle somewhere around 2100, we know it makes at least 45 hp cuz thats what it takes to cruise at 60mph with 2.73s.And since she will do that at something like 30% throttle, we know there is a lot more available at that rpm.
So now lets take half the sparkplugs out. And then,let's guess at how much power she has got left in her at 2100, but with 100% throttle, with just 3 working cylinders.Well first off it has to be less than 180/2 =90, and since we are at 2100,and not at peak hp, it has to be at less than say 1/3 of peak.So I come up with about 30hp So now if the tranny is going to suck 25 of those away , and the rest of the powertrain and accessories suck up 15 or 20, well you are left with less than nothing to move the car.
But I can guarantee you this one thing; If you have a healthy 180dynohp 225, it will still go 60mph on just 3 cylinders. That would mean it is still netting 45 hp or more
So, one would kindof need to see the test parameters, that generated the 25 hp loss.