rear end gears and tire size chart to figure rpm speeds

[rodder25]

I am trying to figure rpm's with 4-10 gears with mickey thompson 33x22x15" street radials at 60 mph thanks for any help.

 

[409T]

Google is your friend. Try "tire size rpm chart" or "tire size rpm calculator"

 

[Spanky]

Here's a little formula that I use:
Axle ratio x speed x trans ratio x 336.13 ÷ tire dia = RPM

What I came up with for my TH 350 tranny using a 3.08 rear gear and 26.5 in dia BFG Radial TA's . . .

MPH .. 3rd (1:1) .. 2nd (1.52:1) .. 1st (2.52:1)
30 ... 1,172 ... 1,781 ... 2,953

35 ... 1,400 ... 2,000 ... 3,500

40 ... 1,563 ... 2,375 ... 3,938

45 ... 1,750 ... 2,675 ... 4,400

50 ... 1,953 ... 2,969 ... 4,922

60 ... 2,350 ... 3,500 ... 5,907

 

[Indycars]

This will get you close or you can download the Excel file and put in any numbers you like.



For those with other tire sizes and cruising speeds, look below.


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[choppinczech]

https://www.summitracing.com/popup/calcsandtools/gear-ratio-calculator

 

[Jim B]

Nice that this forum offers plenty of help without issue. Just sayin'. Nice work guys.