View Single Post
Old 04-05-2012, 06:22 PM   #181
Deslock
Senior Member
 
Deslock's Avatar
 
Join Date: Oct 2009
Drives: 2013 DZE/01 (sold for MX5 ND1)
Location: western MA
Posts: 871
Thanks: 265
Thanked 269 Times in 133 Posts
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quote:
Originally Posted by ZDan View Post
You forgot to add weight for the driver and some fuel. Try it again with 3250 lb. instead of 3050.

Mazda lied about the RX-8's hp, but not by THAT much!



Especially for lower-powered cars, traction doesn't affect trap speed much.
Some mags correct 1/4-mile results for temperature and air density.
Minor differences in drag (Cd*A) won't change results much.

The equation *is* a quick/dirty approximation/estimate. But it's a very good one for getting in the ballpark.
Oops you're right I did forgot to add for the driver, but I still don't think that formula is accurate enough to indicate whether it was 2933 pounds or 3029 pounds (especially given the variance in quarter mile results... I've seen a lot more 93-94.x than 95.x trap speeds reported).

Last edited by Deslock; 04-05-2012 at 06:47 PM.
Deslock is offline   Reply With Quote