Moving from MT to Truggy

[crazyjr]

I am moving to my truggy from my revo, I am moving the setup from the MT to the truggy. The motor is a 1515/2.5d/f neu motor the esc is a quark 125 w/koolflight UBEC, The plan is for 4-6s lipo use. My only question is, I have a 19 and a 20 tooth pinion at 1.0 mod. Can i run the truggy on the 2.5D with these pinions? Or, would it overheat with that gearing? I know the 2.5D 1515 is a torque monster.

here is the calculator for the 19 pinion At 4s lipo

Differential Ratio: 4.3
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 48
Pinion Tooth Count: 20
Total Voltage: 14.8
Motor KV: 1650
Tire Diameter (inches): 5.65
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor Coil Resistance: 0.01
Spur/Pinion Ratio: 2.4 : 1
Total Ratio: 10.32 : 1
Tire Circumference (inches): 17.75 inches (450.85 mm)
Rollout: 1.72:1
Total Motor Speed: 24420 RPM
Vehicle Speed: 39.77 mph (63.89 km/h)
Effective KV Value: 1650
KT constant: 0.82 oz-in/A

[dirt101]

I would say thats alittle on the high side for gearing. I would also say 5s would be best for the 2.5d. I had the 2.5d in my CRT on 6s and everytime I actually took it to the track I wished I had 5s instead of 6.

[crazyjr]

I know aboput the 2.5D 1515 on 6s, it's a beast. What it is, is my revo is not holding the power good enough. Every time i run it something happens, This time, it was the pinion on the rear diff (2nd one of the V.1 RC-M 1/8 diff conversions) With Mike not making the diff conversions anymore, I am shelving the revo for a truggy. I am just wondering if i need to buy a smaller pinion, when i get the parts for the conversion. Of course i am going to support the monster for the motor plate, battery box and if need be the pinion.

The truggy will be my Losi 8T (not 2.0)

[simplechamp]

I agree with dirt101. Running 5S would put you right into that 30k RPM sweet spot, and then you could gear down a little bit and still be at 40mph with a lower rollout. On my vehicles I try to keep the rollout no higher than 1.5, and have never had any heat issues when doing so.

[E-Revonut]

I ran that motor in my truggy on 5s with a 15-17t pinion, any more than that and your pushing very high temps, I was about 155-160 at the end of 18 minutes.

[crazyjr]

Originally Posted by simplechamp

I agree with dirt101. Running 5S would put you right into that 30k RPM sweet spot, and then you could gear down a little bit and still be at 40mph with a lower rollout. On my vehicles I try to keep the rollout no higher than 1.5, and have never had any heat issues when doing so.

What exactly is rollout? I seen it shown in BrianG's calculator ( the ratio for 1:1 rollout), but I never really paid attentioin to that. I just geared it till i was comfortable and liked the heat of the motor