Aerodynamics in vehicles

[taper41]

Hey fellas, I'm new on this site, and have always been interested in aerodynamics. I have a lot of question that I'm hoping you can answer for me based on top speed performance for a 2 wheel and 4 wheel vehicle that are the same size and weight.

my main reason for these question is to really figure out what is the more important part of the equation when it comes to top speed , and what factors of drag and force are significant and insignificant.

I know that aero drag is squared and power is cubed during which the vehicle is moving at a faster rate.

but i was told that if you change either one by the same percentage you will get the same result, along with this.

the other question is rolling resistance and how important is it, our two wheels going to have less rolling resistance than four, or the same, seeing as though the same amount of weight would cause 2 wheels to have a heavier load than if it was spread over 4

thank you

[MetroMPG]

If you haven't seen it yet, this calculator may answer many of your questions:

Aerodynamic & rolling resistance, power & MPG calculator - EcoModder.com

The formula on which it's based is posted with explanations at the bottom of the page.

Don't know offhand the answer to your question about 2- vs. 4-wheel rolling resistance though.

[taper41]

The chart is somewhat a help, but i still have a question on power and the relation to to top speed vs the relationship between aerodynamics and top speed, and is one more important than the other

[tortoise]

If you want this to turn out better than your visit to the Landracing forum, I might suggest you show a willingness to do a little mental work on your own. Why don't you try running some examples on the calculator and report your results? You can answer your question for yourself.

[2000mc]

Originally Posted by taper41

..... a 2 wheel and 4 wheel vehicle that are the same size and weight.


the other question is rolling resistance and how important is it, our two wheels going to have less rolling resistance than four, or the same, seeing as though the same amount of weight would cause 2 wheels to have a heavier load than if it was spread over 4

do you have any examples? i dont know what i would compare as far as a 2 wheel and 4 wheel vehicle that are the same size and weight

weight being spread out... you could run wider tires on a 2wheeled vehicle or skinnier tires on a 4wheel. i'm guessing less is more, i thought semi's were running the super single tires instead of dually for fuel saving/rolling resistance