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optimal final drive?

1551 Views 11 Replies 5 Participants Last post by  EWmudracing
need some opinions on what you guys think an optimal final drive should be. for dirt drags and mud bogs. for example how far off would 3.50 a 205 transfer case and 38.5 tires be way off in low range? the defuser is about done (haha jk jeff) and looking for some help
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With that ratio and tire size with a np205, assuming its a c-6 tranny ur final ratio is
17.048 @ 7000 rpm's.:D What ratio are you looking for as a final drive?
it is a c-6 only gonna turn about 6500 but what im wondering is there a magic number everyone shoots for
Thats a hard one!!!:eek: things to consider is horsepower-VS-weight? then peak TORQUE. total rpm range? 4lo, what converter stall? What size of rims for both front and rear? You could have a 39.5x18x15 inch tire and mount it on a 15x16 and you got a 38.4 inch tire. you have to get a tire mesurement @ race weight and psi. alot of hard work and BAD-WORDS to include BEER DRINKING Go into making your combo work for you and your set up! alot of trial and error to get it right.

thats kind of what i figured thanks for your input ill just keep on guessin until it gets fast im shooting for 120 mph wheel speed whether its possible or not

My wheel speed equates to about 93 to 95 mph. Watch my videos, you'll like them!
Critters stuff works well. He's right in there for sure!
Although convertible, Dexter are you looking for final drive like Marshall gave you or wheel speed like Critters gave you?

I personally just go with wheel speed but I know a lot of 1/4 mile and blower guys use final drive ratios.

Just wondering?

I run 513 gears, 205 and a C-6, with 38.5 or 39.5 rear tires. Everybody says I run "TOO MUCH GEAR" as they stare at my tail-gate!
I run similar gearing to critters, except I run a 4.88 front and 5.13 rear. So far this year I have only run the 38.5x11s and it seems to work fairly well. I set my rev limiter at 6800, that calculates to 76.5mph on the rear and 80.4mph on the front. I have had the same arguement as critters has with others, 'too much gear' but they still seem to be the ones falling behind.
Everytime I try to stagger gears like that the truck drives like "***"!
Everytime I try to stagger gears like that the truck drives like "***"!
Its been working in the mud for me, but I did do a dirt drag race the other weekend, that my friends is a bad deal, especially with a locked front diff. I was alittle busy with the steering wheel to say the least!! hard pack track, no loose dirt at all to take up any slip, it got alittle hairy!!
well thanks for the help guys i am for sure looking for wheel speed. and since i dont have any of the low gears like 5.13's i think i will try my high gears and just see what happens and if it seems so i know which way to go now and thats what i needed thanks for the help greatly appreciated

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