My Muggy on 6s *vid*

[JThiessen]

Yes, I did notice that - in addidtional to some hot motors/esc's from trying to dial in the gearing.

[coolhandcountry]

Maybe some day they have a locking tranny diff like on the summit.
Then you can choose which one you want on the fly.

[suicideneil]

Hmm, I think that wouldnt be too hard actually- stick a 1/8 diff in the tranny, but have some special 'coupler' attached to the ring gear (doubled stacked essentially). Then, use the gear shifter mechanism to engage and disengage something like the dog shifter that is used in the stock tranny- only its fixed to the rear output shaft- thus locking the rear shaft to the diff cup and making it act as a spool. Unlocking/ disengaging it makes the center diff act like a center diff again, with the front wheels able to unload some power when you mash the throttle.*

*my design, buy the rights off me for $1000.

[JThiessen]

So I've been doing some shopping for a tranny or a diff, and so far have had no luck in landing a cheap tranny, so I started looking again at the center diff option. I might try to stick a 8T center diff in it, and run it with my 1520 (1600 kv). I used the speed calculator, and with the biggest losi spur, my rollout is still over 2.0, and top speed is still showing at about 50. Given that they want the rpms on the 1520's at 30K max, this one doesn't look too bad for a starting point. Unfortunately though, I can only go up in speed, or add another cell of power.....

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 50
Pinion Tooth Count: 12
Total Voltage: 18.5
Motor KV: 1577
Tire Diameter (inches): 7
Tire Ballooning (inches): 1
Motor Current Draw: 150
Motor Coil Resistance: 0.008
Spur/Pinion Ratio: 4.17 : 1
Total Ratio: 13.78205 : 1
Tire Circumference (inches): 28.27 inches (718.17 mm)
Rollout: 2.05:1
Total Motor Speed: 27282.1 RPM
Vehicle Speed: 53 mph (85.14 km/h)
Effective KV Value: 1474.71
KT constant: 0.86 oz-in/A
Motor Torque: 0.67 ft-lbs
Final Torque: 9.23 ft-lbs
Final Power: 2775 watts (3.7 HP)

Then with a Flux tranny in it:

Differential Ratio: 3.3076923076923075
Transmission Ratio: 2.215277777777778
Other Ratio: 1
Spur Tooth Count: 47
Pinion Tooth Count: 12
Total Voltage: 18.5
Motor KV: 1577
Tire Diameter (inches): 7
Tire Ballooning (inches): 1
Motor Current Draw: 150
Motor Coil Resistance: 0.008
Spur/Pinion Ratio: 3.92 : 1
Total Ratio: 28.69921 : 1
Tire Circumference (inches): 28.27 inches (718.17 mm)
Rollout: 0.99:1
Total Motor Speed: 27282.1 RPM
Vehicle Speed: 25.45 mph (40.89 km/h)
Effective KV Value: 1474.71
KT constant: 0.86 oz-in/A
Motor Torque: 0.67 ft-lbs
Final Torque: 19.23 ft-lbs
Final Power: 2775 watts (3.7 HP)

And finally with a E-Revo tranny:

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1.8333333333333332
Other Ratio: 1
Spur Tooth Count: 68
Pinion Tooth Count: 20
Total Voltage: 18.5
Motor KV: 1577
Tire Diameter (inches): 7
Tire Ballooning (inches): 1
Motor Current Draw: 150
Motor Coil Resistance: 0.008
Spur/Pinion Ratio: 3.4 : 1
Total Ratio: 20.61795 : 1
Tire Circumference (inches): 28.27 inches (718.17 mm)
Rollout: 1.37:1
Total Motor Speed: 27282.1 RPM
Vehicle Speed: 35.43 mph (56.91 km/h)
Effective KV Value: 1474.71
KT constant: 0.86 oz-in/A
Motor Torque: 0.67 ft-lbs
Final Torque: 13.81 ft-lbs
Final Power: 2775 watts (3.7 HP)

So it does look like a tranny will definitely give me the best shot at getting close to a 1:1 rollout, which may in fact be important for a truck this big and heavy.
I'm still kinda scratching my head a little on this. I dont know much yet about how these new big motors are going to work, and still more uncertain about how important getting to 1:1 is........