I run 37s. I donāt believe regearing Is necessary but I do find that she does ride in 8th as much as before. Granted Iāve also added a decked system, heavy full height rack and a clam shell tent so Iāve also increased a fair amount of weight.Any need for a regear?
Good post. Iām running 38s and the diesel donāt care. It just make boost and choochOkay time for some fun, to me I guess.
The L630 Gen III is listed as 480 lb-ft @ 1600rpm, 260hp @ 3600rpm with fueling cut off at 4800rpm. The 8HP75 has a revised program for shorter shifts when paired with the L630G3.
Using the stock 285/70/17 tires and the factory 3.73 gearing versus a BFG KM3 37x13.5x17 and 3.73
At torque peak in 8th gear we go from 65.2mph to 72.8mph anf 55 happening at 1350rpm and 1210rpm respectively. Tire weights are 67lb and 82lb respectively. The nominal diameters are 32.8 and 36.5.
Running the numbers to return the 37x13.5x17 KM3 to the RPM standard of the stock tire you'd need to regear to 4.56 which would put 55 at 1478, peak torque at 59.5.
A few hundred rpm doesn't sound like much but when coupled to 60lb increase in tire weight, those few hundred rpm aren't as easy to make back in terms of boost and cooling.
See attached data.