Hey guys,I was wondering if anyone else has
an opinion about chasis dyno numbers.I know
that the so called rule of thumb is 15 percent for sticks and 20 percent for autos.
for perisidic loss.I just can`t see how taking out a 150h.p. 305 and putting in a 300h.p. 350 would soak up twice the h.p.
The load on the accessories should be the
same,the wieght of the flywheel/flexplate
should be the same or close.This would mean
a 500h.p. b.b. chevy could lose 100 h.p.
through the chasis?
Please let me hear your opinions.
thanks guys

 

It's physics plain and simple and it is the way it is and you can't change it. You can increase the efficiency of the drivetrain to reduce the parasitic losses.

 

The only conclusive way to know for sure would be to dyno an engine, then install it and run it on a chassis dyno.

I know what you're saying...until the internet, I'd never heard of a % loss...all I knew was it took 35 hp to turn a TH400 and 28-30 HP to turn a TH350, and depending on which rear was used (GM 10/12bolt or 9inch, etc) 5-10 additional HP.

FWIW, I tend to agree with you..physics was mentioned above, but using that logic the drivetrain is a constant not a linear change...Hmmn.