Losi 8ight-T & TP4070 (40x102mm) motor

[Dr_T]

New video:

[youtube]dSstjCf_qNc[/youtube]

Turned out my GPS was not broken after the crash at first test-drive, it just did not like to be mounted next to the Hobbyking wingcam. Somehow the camera causes enough EM interference for it to loose satellite lock... awesome feature for those using that camera on their planes I suppose.

Same gearing as last post: 23/43 (max Losi brushless mount), 12/47 diffs and 133 mm OD tires, yielding 114 km/h nominal voltage, no-load, unballooned, zero-timing wheel speed. Interesting findings:

• With these tires and on this (less than optimal, but hey... it's a Truggy) surface, I can't seem to put much more than 4 kW of power on the road effectively. Trying to accelerate faster causes so much loss of traction I can't keep a straight track (as demonstrated in the vid).
• Due to this limited acceleration, it takes about 7 s and 150 m to get to 120+ km/h - got to work on that, as that's some embarrassing performance :D.
• On a fresh Turnigy 5.0Ah 60C battery, Voltage drops 3.6-2.8 V in the first couple of passes (below 22.2 V nominal Voltage), with the biggest drop at the first pass.
• At 120-125 km/h load, RPM is around 30k; taking into account the Voltage sag, this is about 92% of the unloaded RPM.
• After reaching peak RPM (top speed), the Power component used for acceleration dies out and Power supply drops to around 3 kW, which appears to be the amount required to sustain the 120-125 km/h speed for my car (sum of aerodynamics, rolling resistance, drive line friction, electric losses).
• At top speed, the temperature of the sensor on the motor stabilizes, or even drops (I know this says nothing about the motor's internal temp, but I still think it's funny). Factors involved are likely the increased airflow, the drop in Power consumption at steady state and running closer to peak efficiency RPM than while accelerating.

Total 3 packs of 5.0Ah


Zoomed in at 5 interesting passes


Combine speed profile


Single battery speed profile