Gear and tire math
Thanks for
the response. How does the math work? (26/28)x4.1 ?
That comes out to 3.8071427
of course we're not coming from a true 26" tire either.
25.6/28 = 0.9142857 x 4.10 = 3.7485713
of course this could be completely wrong.
the response. How does the math work? (26/28)x4.1 ?
That comes out to 3.8071427
of course we're not coming from a true 26" tire either.
25.6/28 = 0.9142857 x 4.10 = 3.7485713
of course this could be completely wrong.
All you do is pick a RPM at a given MPH with the 4.10's, change to 28" tall tire, see the diff, and then play with the rear end ratio # to get that mph/rpm in line and that would give you the equivelent. When the 28" tall tire is factored in the gear ratio is about 3.90.
FYI, working with the gear calculator.
There is a 500rpm diff between 26" to 28" tall tires on 4.10's using 2.66 1st gear ratio. I picked 40mph @ 5700 rpms and then on a taller tire it became 40 mph @ 5200
Then I turned back to the 26" tall tire then played w/ the rear gear and it got it back to the same RPM range/mph which was 3.90's
FYI, working with the gear calculator.
There is a 500rpm diff between 26" to 28" tall tires on 4.10's using 2.66 1st gear ratio. I picked 40mph @ 5700 rpms and then on a taller tire it became 40 mph @ 5200
Then I turned back to the 26" tall tire then played w/ the rear gear and it got it back to the same RPM range/mph which was 3.90's
Last edited by BlackScreaminMachine; Aug 12, 2009 at 07:13 AM.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo If you 
it, you will find the mathematical equation to figure this out, I used this site as it makes it easier for me.....
https://ls1tech.com/forums/gears-axl...ere-first.html
http://www.f-body.org/gears/ (for the calculator)
now MIND you, if you run a bias ply, there is something that most people DO NOT account for is tire growth and a 28" tall M/T ET Drag will grow about 1 addtional inch at speed so in the end the calculator will give you a ball park and does not take into consideration any other variables except tire height, rpm, trans ratio.
This other calculator uses the formula to the decmile point is more like your math.
http://www.fbody.com/calc.htm
I was getting a 400 rpm or so swing and to get to approx the same rpm, the gear was like 3.8x
it, you will find the mathematical equation to figure this out, I used this site as it makes it easier for me.....https://ls1tech.com/forums/gears-axl...ere-first.html
http://www.f-body.org/gears/ (for the calculator)
now MIND you, if you run a bias ply, there is something that most people DO NOT account for is tire growth and a 28" tall M/T ET Drag will grow about 1 addtional inch at speed so in the end the calculator will give you a ball park and does not take into consideration any other variables except tire height, rpm, trans ratio.
This other calculator uses the formula to the decmile point is more like your math.
http://www.fbody.com/calc.htm
I was getting a 400 rpm or so swing and to get to approx the same rpm, the gear was like 3.8x
