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Author Topic:   gear ratios
Dirt Newbie

Total posts: 2
posted August 02, 2005 10:00 AM  
hi i am looking at changing rearends in my car. right now i have a 3800#, 83 caprice with a 355, turbo 350 running in 2nd gear, with 235/60/15's that measure 82" circ,and a 3.73 gear. we run on a high bank 3/8 mi track. my rpm is only around 5400rpm and would like more. i have a rearend ready to go that has 2.56 gears in it.and was just wondering how much that would bump up my rpm if i would run in 1st gear and run 255/60/15's that measure 86" circ. thanks for the help

Dirt Maniac

Total posts: 122
posted August 02, 2005 11:39 AM  
You should end up somewhere close to 6000.

Dirt Roller

Total posts: 18
posted August 02, 2005 11:40 AM  
second gear (1.48) x 3.73 x 235/60 = 76 mph @ 5400 rpm
first gear (2.52) x 2.56 x 235/60 = 65 mph @5400 rpm

switching to 255 tires changes those to 78 and 67 mph respectively.

what's your redline (and where is your power peak)? to do 80mph in first gear with 2.56 gears and taller tires = 6400 rpm

Dirt Newbie

Total posts: 2
posted August 05, 2005 10:50 AM  
well thanks for the help guys. i hope to run the car around 6000-6200 rpm with the 255/60's on it. i race in one week so we will see.thanks again

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