Lightweight 19" vs OEM 18" vs OEM 17"
#76
Join Date: Jul 2005
Location: Torrance, California
Posts: 1,489
Likes: 0
Received 5 Likes
on
5 Posts
Originally Posted by redlude97
Except they will fallover/ angle at any significant distance that would be required to actually determine a differene. Easy to do in a class, not so easy in real life
#79
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.
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.
#83
Originally Posted by 636Racer
just take a look see for yourself. get a bucket, fill it up with water and swing around the bucket and adjust the length. the farther bucket the more force you have to exert to get it started, as well as maintain it. the shorter the distance, the lesser the effort. hard to explain, but the closer the mass is towards the center...the easier it is to move.
So for rims, 19s carry more volume outward...and as speed greatly increases...it virtually becomes heavier (like the bucket of water). tires are a nother factor. balgh...i give up.
So for rims, 19s carry more volume outward...and as speed greatly increases...it virtually becomes heavier (like the bucket of water). tires are a nother factor. balgh...i give up.
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
#84
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.
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.
#85
Originally Posted by shabarivas
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
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
Last edited by EWG35; 05-05-2008 at 12:16 AM.
#87
Thread
Thread Starter
Forum
Replies
Last Post