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Re: HP vs topspeed

To: "Jim Hill" <Jim_Hill@chsra.wisc.edu>, <triumphs@Autox.Team.Net>
Subject: Re: HP vs topspeed
From: "Ron and Angie" <nottingham@alltel.net>
Date: Mon, 21 Dec 1998 18:29:49 -0500charset="iso-8859-1"
>Note, however, that the horsepower figure you get will be the horsepower
>rating at the RPM reached at top speed. If you're going as fast as you can
>and you're not at the red line, there's probably more power left.
>


Sorry, Jim, that's not true ALL the time.  That's an assumption (we all know
what assume does!).  Allot depends on the horsepower curve.  For instance,
if a given car redlines a 6000RPM, but peak power is produced at 5000RPM,
you have a downward curve from 5K on to 6000.  In reality, there would be
less power at redline than at 5000.  Since most stock engine's power curve
from peak to redline drops dramatically,  top speed at redline could
actually be lower than at 5000.  It depends on how much HP is made at
redline, and how much HP it takes for a particular car to maintain a
particular speed.  But that depends on how much of a drop in power is
occurring from peak to redline, and the gearing that is used.  For instance,
take the 6-spd C4 'vette, it's top speed occurs in 5th gear, not 6th, but
the highest speed in 6th gear occurs way short of peak power and redline due
to the gearing.

If the list wants the formulae for this, I will post or set up a web site.
I must warn you, it WILL have allot of physics and calculus involved.  It's
not for the faint of heart.

Ron and Angie - Dalton, Ga
84 300ZX Turbo    77 Spitfire      92 Tempo GLS    62 Vitesse
IZCC# 4779
"I gotta go, you're killing me!" - Kim Peterson, WGST 105.7, Atlanta


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