Well, I don't know the context of the original statement. But there are two
simple things to consider. One is that the car can be quick, the other fast.
Quick has to do with the old F=m*a equation we all grew up with. As you can
see, mass or weight divided by gravity is included. The force is the
tractive force at the the rubber/road interface and can be figured from
torque at that point. I don't think there is any quadrupling there. As to
fast, two main effects, one is rolling resistance which does indeed include
weight but is not really a factor until some pretty high speeds are reached
(like 300 mph...). The other factor is aero drag, which has no weight in it
at all, But horsepower does go up as the cube of velocity (ft per second).
So I am not really sure wat he was talking about...
mayf
----- Original Message -----
From: "G Shaw" <emmakita@hotmail.com>
To: <tigers@autox.team.net>
Sent: Monday, August 20, 2001 10:40 AM
Subject: Power to weight ratio (non tiger)
> Hi
>
> I know that the engineers on this list will have an answer for this. Last
> night on a repeat of "Junk Yard Wars" an expert said that the power to
> weight ratio that we all know is so important in making cars go fast is
not
> a simple relationship of dividing one number by the other. He said that as
> the weight doubles the power need quadruples. If this is so then a 200 hp
> 2000lb car would be twice as fast as a 400 hp 4000lb car, no? Is this
true?
>
> Greg
>
> _________________________________________________________________
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