tire change

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novaz
Posts: 113
Joined: Sat May 14, 2005 10:26 pm

tire change

#1 Post by novaz » Fri Mar 13, 2009 1:57 pm

Instead of changing out my rear gear I am thinking of dropping down from a 28" tire to a 26" does any one have an idea how much that would affect my top end rpm currently I use a 3.73 rear gear.
Thanks
Roy

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vegaracer
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Re: tire change

#2 Post by vegaracer » Fri Mar 13, 2009 11:21 pm

Should be equal to approximatley a 4.02 gear. So if you were running 7000 rpm before, you would be running roughly 7500 now.
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wikd69
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Re: tire change

#3 Post by wikd69 » Sat Mar 14, 2009 1:13 am

novaz wrote:Instead of changing out my rear gear I am thinking of dropping down from a 28" tire to a 26" does any one have an idea how much that would affect my top end rpm currently I use a 3.73 rear gear.
Thanks
Roy
I'd suggest trying the calculator on the Mark Williams website. It's pretty good. Youi'll want to figure out what your runout is on those tires and try to guesstimate your rpm loss through the converter, but you should be able to get pretty close with this calculator.

I used this when I selected my gear ratios and tire size in my first build out.

http://www.markwilliams.com/calculators.aspx
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Blown 427 BBC, TH400 w/Brake, Back-Half Ladderbar
Narrowed 12-Bolt, 4.10 Gears, Spool, Moser 33 Spline

http://www.marsh-racing.com/harrys_camaro-1.htm

racnrog
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Re: tire change

#4 Post by racnrog » Mon Mar 16, 2009 5:57 pm

i had 4.88 gears and a 27" tall tire i went through @7600 a 29" went through @ 7200 a 30 went through @7000 its about 200 rpm per inch from my experience hope the info helps

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novaz
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Re: tire change

#5 Post by novaz » Tue Mar 17, 2009 9:50 am

Thanks Guys

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