So our cars have a P/W of around 13:2:1 roughly.

That's the weight of the car divided by the rwhp. 3300/250.

That is if my above numbers are correct to start. Regardless of that...what does that mean? The higher the number or the lower is better?

Obviously the closer the two racers numbers are the more "aligned" the race will be.

It's good to be able to figure this out when racing so you'll have a good idea of how the race will go.

Those damn Civic hatchbacks for instance can be killers. If you can get an idea of his rwhp and weight, you'll know if you stand a chance.

 

Except for gearing.

 

its a good gauge of 2 cars in terms of highway speed. it doesnt account for traction which has a huge part of the launch, but from a roll, its a good comparison(assuming equal gearing).

lower is better. its essentially the amount of weight each HP must push.

 

Power to weight ratio is nice to know, but like Fly By Z said, there are things that it does not take into account. Gearing, for instance, is one thing. The location of the power peak is another.

Regarless of that, you the ratio as you calculated it to be as low as possible. It boils down to the fact that a greater force is required to accelerate a 3000lb object to x miles per hour than to accelerate a 2500lb object to x miles per hour. Therefore, if my HP is constant at 300hp, and I strip the interior out of my car and save 500lbs, I'll be lowering the weightower ratio and in theory I'll have better acceleration since the force is constant.

In some amateur racing circuits, they limit you to a certain power to weight ratio to keep the races competitive. In these instances, driving skill, choice of gearing, and where you make your power are much more important.

 

Since your ratio is showing Lb/HP, you want it as low as possible. This would mean each HP needs to move less weight which is a good thing.

-D'oh!

 

It's not a bad overall measure for accel's, although many times rotational inertia is forgotten as an important part of the weight equation. Weight has a minor affect on top end speed except it's contribution to rolling resistance. Another important resistor is aerodynamic drag. Top end speed and the later stages of the 1/4 will be influenced by aerodynamics. Our Cd of .21 is not bad but contributes significant aero force at high speeds. There's also internal resistors. Combustion efficiencies, drive train loses, etc. AT's have more loss than MT's for example. For the twisties, the suspension has a major impact on performance. And of course, there's the ever present variable in driver skills.

 

Cd is .31 not .21.

 

Civics arent rwd, they are fwd.

 

My bad.

Cd for the track is listed as .29 and for the other models is .30. I wonder if these include the Zaino effect ;-)