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Discussion Starter #1
Ok so the stock fan blade rims "18 in." weigh 26.5 lbs each...the ones im looking at online at american muscle are 32 lbs each...am i going to notice any difference at all in acceleration with 5lbs added to each wheel?
 

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a little bit, its why people don't like 20's, they weigh and slow the car down... if you can get once that weigh less, the better it is.
 

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Go on a diet! I love my 20's but they did weigh-in at an extra 3lbs. each. I gave up beer for two days and dropped the 12lbs. to offset.....LOL
 

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Check the weight of the tires too. Even using light wheels, my 275/35 x 20s add 10lbs a corner. Does it make it slower? Doesn't seem to.
 

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So whats a good lightweight 18" or lightER weight 20"?
 

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Skirt Chasing Philanderer
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20 plbs equates to 2 tenths in the quarter. Maybe more than than becuase you are talking about 20 rotating plbs.
20lbs. doesnt equate to 2 tenths. Otherwise I would be able to run 10s by simply removing seats and carpet... From what I heard 100lbs equates to 1 tenth. The other thing about 20s other than the weight is your changing your gearing with the larger rotating wheel/tires... Smaller diameter will spin more per one revolution than a larger diameter per that one revolution.
 

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20lbs. doesnt equate to 2 tenths. Otherwise I would be able to run 10s by simply removing seats and carpet... From what I heard 100lbs equates to 1 tenth. The other thing about 20s other than the weight is your changing your gearing with the larger rotating wheel/tires... Smaller diameter will spin more per one revolution than a larger diameter per that one revolution.
20 lbs of rotating mass though?
 

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Discussion Starter #13
Yeah im not getting 20's i was talking about staying with 18's haha
 

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20lbs. doesnt equate to 2 tenths. Otherwise I would be able to run 10s by simply removing seats and carpet... From what I heard 100lbs equates to 1 tenth. The other thing about 20s other than the weight is your changing your gearing with the larger rotating wheel/tires... Smaller diameter will spin more per one revolution than a larger diameter per that one revolution.
Your right. I was thinking 10hp is 1 tenth, it is about 100plbs a tenth. Also 100plb equals ten hp.

I still think that becuase we are talking about the wheels that the weight does make a bigger difference than if was just 20plbs inside the car. It has to use more torque to turn the extra weight of the tire.

Anyway sorry for the blonde moment.
 

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so wat would be my gear ratio for my car. I have 3.55 and have 20s with 285/30r20 but at the end of the month im going to 305/35r20..
 

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Skirt Chasing Philanderer
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Theres no exact formula ( that I know of ) to calculate gear ratio with wheel diameter involved but If I had to guess at it I would say it would be the equivelant of 3.50-3.52...
 

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I Poop Entirely Way Too Much
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It also depends where the is located weight in the center doesnt affect the inertia as much. I got better wheels on my old car which weight just bout the same but there was definately an increase in performance.
 

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so wat would be my gear ratio for my car. I have 3.55 and have 20s with 285/30r20 but at the end of the month im going to 305/35r20..
If you want to know what your new set up will feel like (I say "feel like" because your ratio is what it is 3.55).

find the number of rotations your current tires turn in a given mile (call this A), find out the rotations per mile of the tires you want (call this B). Make an algebra equation in which you have B/A = x/3.55

Multiply B by 3.55 and then divide the result by A.

So If I went from a tire that rotated 750 times per mile, up to a tire that rotates 775. My effective ratio goes from 3.55 to 3.43.
 

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If you want to know what your new set up will feel like (I say "feel like" because your ratio is what it is 3.55).

find the number of rotations your current tires turn in a given mile (call this A), find out the rotations per mile of the tires you want (call this B). Make an algebra equation in which you have B/A = x/3.55

Multiply B by 3.55 and then divide the result by A.

So If I went from a tire that rotated 750 times per mile, up to a tire that rotates 775. My effective ratio goes from 3.55 to 3.43.

Correction, keep it A/B.....for a ratio of 3.66
 
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