need help with gear ratios, stock final gear ratio's not spaced out evenly - why? |
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need help with gear ratios, stock final gear ratio's not spaced out evenly - why? |
jimkelly |
Jun 22 2011, 04:13 PM
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#1
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Delaware USA Group: Members Posts: 4,969 Joined: 5-August 04 From: Delaware, USA Member No.: 2,460 Region Association: MidAtlantic Region |
for me - chevy v8 - stock 2nd is fine as a first gear, but it winds out fast, as does stock 3rd, as does stock 4th, and 5th is fine, but taller would get rev's down for highway cruise-ing ( 3000 rpm at 65 +- ) on 195x60x15 tires.
my question is why are stock final ratio's not spaced out evenly? stock 3.091 1.889 1.261 0.926 0.710 3.091 x .61 = 1.889 1.889 x .66 = 1.261 1.261 x .68 = .926 0.926 x .77 = .710 evenly would be ... 3.091 2.496 1.901 1.306 0.710 for my v8, i am thinking of course to delete cantilevered first - thus i can use a beat up slider ; ) stock 2nd 1.889 ?? 3rd - i need the right gear for inbetween stock 1.889 and 0.710 4th - use stock 5th ZD 0.710 5th - use flipped H 0.59 as an overdrive gear. how the hell do i calculate the correct final gear ratio for my 3rd gear? looks like an R (1.080) 25:27 - or - a flipped V 27:25 - is about right ?? jim Attached thumbnail(s) |
messix |
Jun 23 2011, 09:02 PM
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#2
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AKA "CLUTCH KILLER"! Group: Members Posts: 6,995 Joined: 14-April 05 From: between shit kickers and pinky lifters/ puget sound wa.north of Seattle south of Canada Member No.: 3,931 Region Association: Pacific Northwest |
lets just say you are building a 4sp gear box [2=1,3=2,4=3,5=4]
with the torque of the v8 you really don't want to "close ratio" the 1 to 2 shift because you will over power the tire pretty easily [you aren't fighting aero drag at all and all power will be hitting the tire hard], so a wider ratio from 1 to 2 is better to live with. from there the stock third will match shift rpm pretty good with a 4th gear flipped h/a gear set. this will make freeway driving nice and give you a good top end. just make sure your clutch is up to holding the power. |
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