View Single Post
  #1  
Old 06-14-2023, 02:21 PM
Tom Vaught's Avatar
Tom Vaught Tom Vaught is offline
Boost Engineer
 
Join Date: Dec 2001
Location: The United States of America
Posts: 31,302
Default

Quote:
Originally Posted by Lee View Post

Recently, I tested my friend's TOTALLY stock '79 Trans Am, 403 2.73 gears, 27,xxx miles. It was rated at 180 or 185hp, which I always assumed to be flywheel (since chassis dynos didn't really exist at the time). On our DynoJet, it put 178 to the wheels. That was through the crappy old pellet catalytic converter.

About as accurate as I can state is the RWHP will be about 20% lower than flywheel - but with a +/- range of up to 18% (2% to 38% of flywheel).
Clayton Chassis Twin Roll Dynos have been around from the early 1960s, not 1979. (think Dyno Jet, etc).

Your 18% Trans/Chassis/Tire loss number is "SPOT ON" vs what Ford has used for many years (and verified yearly on the Company Test Tracks).

Tom V.

__________________
"Engineers do stuff for reasons" Tom Vaught

Despite small distractions, there are those who will go Forward, Learning, Sharing Knowledge, Doing what they can to help others move forward.