High KV 6S - How to find that extra gear...
For the past two months, a group of us racers have been testing various KV motors on 6s. We’ve been trying to find that sweet spot between flight time and warp speed levels of performance. For most of the 2019 racing season I have been running the MCK motor from T-motor, which are 1800KV. Before this I was running the F60 Pro iii 1750KV, which has been established as the standard KV for a 6s racing rig.
The MCK motors are amazingly smooth and the extra 50kv really gave me that extra punch of juice that I was missing on my generally heavier box-style frame that I’ve adopted. But, like all adrenaline driven racers, I was always looking for more speed! Enter the likes of MewoFPV (Cory Ibanez) and Chief (Alex Campbell). These two guys like speed just as much as any of us hardcore racers do. Chief is hands down the one pilot who will never lose a race because his quad copter was slower than anyone in the field. A couple months back he had mentioned to me that he was running 2500KV 6s 👀 To me this sounded ridiculous, until I discovered the throttle limit trick. I cannot confirm or deny whether Chief runs a throttle limit, but knowing him he probably just sends it at 100%.
I have now transitioned to 2150KV F 60 Pro iii motors from T-motor, which myself and Mewo helped develop to be able to withstand the torture that we put them through. Equipped with high-temperature silver-core windings able to withstand up to 240C, the overall stability of the motor has been enhanced. The threading has also been strengthened to prevent stripping or fracturing of the motor shaft.
T-Motor f60 pro iii 2150kv
We worked with T-motor to develop the perfect racing motor for 6s throttle limit and 5s no limit. The result is a single strand winding motor, which is different than the multi-strand winding of the previous F60 Pro’s
For a technical explanation of this, please have a look at Oscar Liang’s post. There are a couple methods for limiting throttle and some scenarios and reasons why you would ever want to do this.
One method involves setting up your radio to limit throttle by using a switch or a dial. I spoke with Evan Turner, widely known as the best pilot in the USA and a top competitor on the World stage, and he had a very interesting perspective on throttle limiting.
“I like to have my throttle limit percentage on a dial, so that I can warm up on a race track. I start off the day around 75% limit and gradually increase the top speed of my quad as I get more and more comfortable on the track. This method really helps me learn the best race line first, then figure out how to hit that line at a faster pace.”
The other method, which is the one I employ, is to simply limit your throttle in betaflight. With my 2150KV T-motor’s I run a throttle limit of 85% on 6s. For 5s I run no throttle limit. Why would you want a motor that can run 5 and 6s you may ask? For longer duration races that you typically find at the larger MultiGP events, you may find that high kv 6s can’t fly longer than 90 seconds. For shorter races like the Cali Clash or many of the tracks we are seeing in Korea, you can really open up the throttle and run 6s with a small limit. If you find that you can’t finish the laps on 85% throttle limit, try dropping down to 80% or switching to 5s. These motors feel great on 5s and it’s a great way to warm up on a new track. Mewo has been a huge fan of racing on 5s lately, as it is easier on your gear overall and feels smoother throughout the throttle resolution.
Since switching to these motors, I’ve been able to get Top Qualifier positions at the last 3 events I’ve raced in - Korea Super Race, Cali Clash 2 and tying with Drobot at WCT2019 (he beat me by .06 so we will call that a timing error 🤣). Here is some footage of these motors ripping around different tracks and environments.
Which props should you run on high kv 6s? From my time travelling around the World to various races this season, I’ve come to the conclusion that the 51466 props from Gemfan are the go-to prop of choice for many top pilots. They are by far the most prevalent prop that I am seeing on the track. The good news is that they can really handle the high kv punishment and seem to really enjoy it! The only drawback of this prop is that it can get bent in some pretty gnarly shapes making finishing races tricky. There are more durable options from Gemfan and other prop makers, but the performance of these is worth the risk IMO.
There’s no free lunch…right? With everything, there is always a give and a take. Obviously running higher KV means that you are going to be pulling more amps and draining your pack quicker. I’ve had to adjust my flying style to be more efficient around the track, which has been a blessing in disguise. As I mentioned above, you should run these motors for shorter duration races no more than 90 seconds. I would never recommend running these for races that last longer than 2 minutes unless your frame is made of feathers.
OK I’m sold! Where do I buy these bad boys?? I confirmed with Anki from T-motor that both Pirofliprc.com and Racedayquads are carrying these motors.