Originally posted by porkchop4
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Transmission and gear choice
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I think someone in the area that knows the tracks/ rules better than me would be the answer. Sometimes Im to eager to help.Gator Engineering
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Checking a manual transmission gear ratio is pretty easy.
Put the trans in second gear (or whatever gear you want to check). Put a chalk mark on the input shaft (the engine side), and another one on the output shaft (the drive shaft side). Turn the input shaft by hand until the output shaft turns exactly one full turn. Just count the number of turns that the input shaft turns in order to turn the output shaft one turn and that is the gear ratio.
It is easier to do this with the transmission out of the car, but you can also do it in the car. Just have one person turn the front of the engine crankshaft and have someone else count the turns at the drive shaft.
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I would agree with what you where told as far as 6.66-7.00 depending on what rpms you want. We ran 358ci w/ 4412 carb (about 400-425 hp), a fast 3/8 and a tight turned 1/2mi. track netted around 68-7000 with 6.20-6.33's. with 10" wheels and around 91" rollout latemodel tires. An auto trans with a standard convertor will have about 200 rpm slip, so keep this in mind if you ever run an auto, this would require about .20 less gear.Josh K.
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I run there regularly. 2011 track champ in factory. Only ran there twice last year do to other track obligations. I run a good 355. Like to turn 7200 to 7400 and run a 7.00 gear with asphalt take off tires. Saginaw with a 10 1/2" clutch set up. Lightweight corvette style flywheel. Car weighs 3200. If you don't want to turn that hard a 6.66 or 6.83 final would be a good start. If you aren't going to run a final gear then I would say a 1.68 2nd gear three speed saginaw with 4.11 gears would be the ticket. That give you a 6.90 final. If your 3 speed is a 1.84 second gear then I would go with a 3.70 gear giving you a 6.81 final. Hope this helps.
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