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hp, speed redux

To: fot@autox.team.net
Subject: hp, speed redux
From: "Jack W. Drews" <vinttr4@geneseo.net>
Date: Tue, 10 Aug 2004 15:36:29 -0500
I'll be darned. you guys are pretty smart.

I just checked my reprint of the Road and Track road test of the TR3 in 
1956. The formulas work out exactly right comparing them against my car.

According to R & T, the TR3 had 100 hp and went 100 mph. I know from the 
limited dyno work I've done that there is a 15% loss in the TR drive train, 
so that means that in 1956 it had 85 rear wheel hp and went 100 mph.

The last time my car was on the chassis dyno it made 130 hp at the rear 
wheels. How fast should it go?

If it goes 120 mph, that's a 15% increase over the original. Using the 
original hp and new and old speeds, the hp required is

85 x 1.15 . 1.15 x 1.15 = 130, just what I have. Amazin and amuzin.

Yeah, I know that a TR3 and a TR4 have different body styles and maybe a 
different drag coefficient, but maybe it's not too different after all. On 
the race tracks, it is not evident that there's much of a difference in 
aero drag.

Now the next question for the esteemed panel is, at this level of 
performance, how many dollars does it take to get an additional 5 mph? -- 
just kidding just kidding

uncle jack 

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