On 4s, if I use a 1515 say 1700kv motor as apposed to a 1512 2000kv motor, which one will give me longer run times/performance. The 1515 is a bigger motor, but w/ less kv will it be equal to the 1512 assuming the setups are identical...just curious that's all.
1. MBX-6 T8 1900KV, RX8 ON 4S
2. MBX-5T 1520, MMM ON 5S
3. MBX-5 ONROAD CONVERSION 1515, MMM ON 5S
4. MRX-3 ON ROAD CONVERSION 1512, MMM ON 6S
5. TEN T 2650 T8, MMP ON 3S
Thats a good question. I'd probably say the smaller 1512 would be the better choice for run times, though performance would depend on the vehicle; anything that could be moved well by the smaller motor wouldnt really need a bigger motor (over kill?).
I know that it is overkill, but, from a performance ( mostly curious about run time )point of view I was wondering if anyone had compared two similar setups and tried anything like this.
Depends on how you have it geared and how you drive. If the two systems are geared the same the slower motor will give you longer runtimes if you spend most of your time at top speed. If you are constantly accelerating the 1515 may be able to pull more amperage (accelerate harder) and your runtime could be lower.
Geared for the same speed I would say the 1515 will have less runtime, as you will probably be pulling the trigger enough to use the extra power.
---JRH---
Last edited by johnrobholmes; 05.18.2008 at 05:57 PM.
I run a lehner 1930/8 (2613kv) or 1940/7 (2239kv) in my buggy; geared for the same speed, I get about the same run time. The smaller higher kv motor is snappier at lower speeds (great for the track), and the larger motor can be geared up for speed runs without getting too hot (of course run time then goes down). If this is going in a truck for bashing, get the 1515; a buggy would be fine with 1512.
A 1515 and and a 1512 of the same wind will have about equal power (differnent gear ratios needed to get the same speed, power, runtime etc), though the 1515 has slightly longer coils so it will be equivalent to a slightly higher turn 1512 motor. If you gear the 2000kv 1512 with a 17 tooth pinion and the 1700 kv 1515 with a 20 tooth pinion, (assuming you use the same wind in each motor) both will have about the same performance and runtime.
Check out my custom converted 8ight:
Sub 7lb, lowest CG of any 1/8 buggy
I think glassdoctor might have used both those motors on 4s for racing in one of his buggies. I think he got a bit better runtime from the 1512, but that was a buggy and I don't know if it would be different for a truggy since it might need more torque.
The 1700kv 1515 is ok on 4s, but you have to gear up a fair bit to get any decent speed and it looses a bit of much. Don't know what it's going in, but I'd choose a bit more kv for 4s.
My Medusa 36-50-3300v2 and Neu 1512/2.5D geared for the same speed gave very close to the same runtime. The Medusa did feel like it was slightly faster and the Neu gave better midrange torque. Unless the one motor is running much more effciently than the other they should give about the same run time if they are geared for the same speed.