What do you mean they will fall over? I've rolled tires before and I don't remember them ever tipping over. True, that you will need a nice distance to see which one will reach the bottom (a small hill is a good start). Yes, it may not roll down the hill straight if the tires are not completely flat at the bottom, are feathered, etc. Hey, just a thought

 

Damn...I just read this thread and...where the hell are the results????

 

Seriously... I just read a whole lot of bitchin and arguing and no results 6 pages later? WTF!

 

There is never going to be a perfect size of rim/tire. It entirely depends on which application you want to use the car for. And whichever size you go with, there will always be compromises.

In this case, the goal was maximum acceleration so the answer would be the lightest wheel and tire combination (which is probably the 17's). Going to a shorter overall diameter with the tires would also be of benefit for gearing purposes.

 

rehashing this old thread to see if there was ever any data on the experiment it started out talking about or if it was just people rubbing their own egos.

 

so..............




bump

 

So whats the outcome????

 

Here is an explanation:

Moment of inertia is defined as:
"The moment of inertia of an object about a given axis describes how difficult it is to change its angular motion about that axis. For example, consider two discs (A and B) of the same mass. Disc A has a larger radius than disc B. Assuming that there is uniform thickness and mass distribution, it requires more effort to accelerate disc A (change its angular velocity) because its mass is distributed further from its axis of rotation: mass that is further out from that axis must, for a given angular velocity, move more quickly than mass closer in. In this case, disc A has a larger moment of inertia than disc B."

I = Moment of inertia = Integral of (Radius^2* dm) where m is the mass and dm is the integrating factor... so basically... inertia increases proportional to the square of the increase of the radius... so if you had two wheels - one 10'' and another one 12'' then the 10'' one would have an inertia of ~100M and the 12'' one ~144M (where M is the mass assumed to be the same) so in 2'' increase... we see a 50% increase in inertia... BAFFLING... where can i get those 2'' rimz LOL

 

It depend solely on the weight of each component.

You also need to do laps around a track. If you are drag racing the 17 could be fastest, unless they weigh more. Hasn't someone done this scientifically yet?

I just bought 20x8.5 iForged and have been told they will weigh 25lbs - 20x10's are 27lbs. My current 18x8.5's weight 27.5 and with tires mounted they weigh 55lbs. These twenties will be lighter, and the tire will definitely be lighter too. I expect these 20's to be faster than my 18's, probably minimally though. Probably a bit rougher ride though.

 

Don't forget to factor in this equation this fact: Not many people drive around without tires. I've seen it on "Cops" a few times but it's never a good idea and they always get busted. If you actually drive around with tires on your car as I do no matter whether you have 16's or 20's the outside diameter of the tire does not change. You can compare two wheels in a battle royale, but without a tires mounted it's a waste of time. My car has a 26.7" outside diameter, no matter the size of the wheel. Tires for the record are heavy! Tires on 16 inch wheels are heavier that those on a 20 inch wheels if the width is the same and it's the same brand. In any case, many times the tire is as heavy or heavier than the wheel itself...

 

I was wondering if a stock G35 coupe rim would fit a g35 sedan? Thanks
This is for a 2003 g35 sedan.

 

Yes they will fit. I had coupe 19s on my 03 sedan

 

And I thought I was a physics geek.