What gears do I need?
Looking at a Ram 2500 to pull a 7K travel trailer. It will be a gasser with the 6.4 hemi. Should I get the 4.10 rear end or will the 3.73 do what I need?
Forum Discussion
Disagree...
First, the formula for determining HP is:
A higher numeric gear ratio will have more rev's from the input shaft (pinion gear) for each output shaft turn (ring gear)
The input shaft/pinion's torque is assumed to be the same in all cases for this discussion...in order to NOT get confused like the quote below where they think only increasing the ICE's torque/HP is it...
Since there are more rev's from the input shaft for each output shaft turn, the numbers of input shaft turns will impart more torque onto that output shaft's single turn
Fact.
Now back to the above HP formula, there is now a change. The torque remains the same, but RPMs is now larger and multiplies torque. The constant stays the same (divisor is 5252). Nothing else changes, except for the increased (fractional) RPM...therefore, there is more HP...
Wikipedia Gear train (there are tons more sites)
What is torque and How does gear ratio affect Torque?
YouTube, Gear transfer torque
This one shows the tranny gears and hope it gets it across...ask why you can't get it going in highest gear...even though it is the same ICE?
YouTube,Car Gear Ratios (Calculate Wheel RPMs, Torque at Wheels, and Force at Wheels)
First, the formula for determining HP is:
HP = torque x RPM / 5252
A higher numeric gear ratio will have more rev's from the input shaft (pinion gear) for each output shaft turn (ring gear)
The input shaft/pinion's torque is assumed to be the same in all cases for this discussion...in order to NOT get confused like the quote below where they think only increasing the ICE's torque/HP is it...
Since there are more rev's from the input shaft for each output shaft turn, the numbers of input shaft turns will impart more torque onto that output shaft's single turn
Fact.
Now back to the above HP formula, there is now a change. The torque remains the same, but RPMs is now larger and multiplies torque. The constant stays the same (divisor is 5252). Nothing else changes, except for the increased (fractional) RPM...therefore, there is more HP...
Wikipedia Gear train (there are tons more sites)
What is torque and How does gear ratio affect Torque?
YouTube, Gear transfer torque
This one shows the tranny gears and hope it gets it across...ask why you can't get it going in highest gear...even though it is the same ICE?
YouTube,Car Gear Ratios (Calculate Wheel RPMs, Torque at Wheels, and Force at Wheels)
RCMAN46 wrote:
The 4.10 gearing will not give you more horsepower.
Gearing will not change the horsepower of a vehicle period.
Only modifications to the engine can increase horsepower.
