[Land-speed] Chassis Dyno Operations

[Kirkwood]

The only chassis dyno pull I have witnessed in the last 10 years was a
roadster with a C-10 automatic. That run was done in 2nd gear not high gear.
When I asked why 2nd gear the operator said the same as you, it didn't make
any difference but it kept all the rolling speeds lower and he preferred to
test that way. Even at that I thought the building was going to collapse.
The only justification I could see for a high gear pull is to quantify
actual RWHP. If high gear is 1:1 and is a few percent more efficient than
lower gears then you are quantifying the actual HP producing terminal
velocity. Any gear less efficient would be an inaccurate result. Maybe I
should rephrase that. Even if overdrive is less efficient you would want to
test in the gear that is providing terminal velocity. Isn't that the RWHP
that counts?
-----Original Message-----
From: drmayf [mailto:drmayf at mayfco.com]
Well, this wasn't an exercise to try and find out why a dyno I have
didn't work (I don't have one).  I was asking why we do testing the way
it is done. What is the rationale for doing it that way?