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Old 08-21-2007, 02:16 PM
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How to size engine, trans, rear end

I have a 2400lb 2 seater with a SBC 350 mild cam, Edelbrock manifold, Saginaw 4 speed (don't know the ratios) and a 3.08:1 10 bolt posi. don't need 1st gear at all, is that typical? What would others suggest for a fast streetable drive train? how much more engine could I get to the pavement?probably limited to 26" dia tire

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Old 08-21-2007, 03:00 PM
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mild 350 is about 340ft/lbs of torque
340ft/lbs x 3.08 gears =1047ft/lbs of torque actually applied to the tires
2400lbs/1047ft/lbs=only 2lbs of weight per 1 ft/lb of force

normal 3200lb car/1047ft/lbs at the tires=3lbs of weight per ft/lb of force

that's why you don't need first gear....about 50% less weight than typical for that motor torque output at the tires

3.50 gears=1190ft/lbs to the tires (makes a big difference for neck jerk), leave the motor alone
3.73 gears=1268ft/lbs ="if" your suspension is set up for traction....cause in the rain....it will want to break loose with only 800lbs(?) on the rear tires to keep it planted to the ground

Last edited by red65mustang; 08-21-2007 at 03:19 PM.
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Old 08-22-2007, 09:16 PM
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How to size

I'd have to agree with Red, I have a roughly 3400 pound car with maybe 400 hp and a 3:55 gear. It's a handful on any damp or wet road and will the spin the wheels from a rolling start with no problem. Then again, I used to race motorcycles, so, is there really such a thing as too much horsepower?......LOL.
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