I am looking to possibly re-gear my truck for a better final drive ratio in 4 low for sled pulling. I have done some research but have not found what I'm looking for. I gather a 13.0-14.0 final drive is a target for sled pulling but I have a 4R100 and all I have been able to find is ZF or NV values for a final drive ratio. I'm running a 4R100 with 35's with 3:73's with a 271 T-case, with running approx 3400rpms= not enough of a final ratio for third gear in 4x4 low. I'm in the 10.0 ratio range with the convertor locked??? not sure if I did the formula right.
What gear ratio/tire size set-up is optimum for what I'm looking for?
This is for the work stock class (2.5) and I'm at the low 500hp range.
4.56 will get your rpms up but I preffer a 33" inch tire...if your still driving the truck on the street which I asume so with a 2.5 truck and wana keep the 35s id go with a set of 4.10s and a true-trac l/s front and rear, then your rpms will be up some on the track and not to high on the freeway
I appreciate the info...I wouldn't mind going all the way up to 4:56
and dropping tire size for pulls if it will all come together in the
end. As far as the true trac I was planning runnning one in the rear
and an ARB in the front.
Motor is good, trans is good, now its time for the axles.
What is the final drive ratio with 33,s and 4:56 gears...I'm conning up with 11.65???
well Im assuming 3400 since thats pretty much where the power stops on the dyno. I was hoping since it is such a low rpm I could try and gain some back by re-gearing and tire swapping. I'm getting tired of slow pulls and not enough rpms at the big end of the track with 35's and 3:73's. I guess i'll run 35's on the street and 33's for sled pulling with 4:56 gears...
Sounds as good as I can get for a street driven sled puller?
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