What Brushless systems are people running?

[DerbyDan]

Hi guys,

I'm currently racing indoors with my touring car on a small carpet track but would like to make a return to running outdoors offroad - possibly using the Worlds RC10 project car that I am in the process of re-building.

The touring car has a 'TC' spec LRP Sphere ESC supplying sensored power to a Hacker (German made) 13.5 motor.

I'd like to run a 6.5 motor (this seems to be the norm for the 'modified' class in off road over here in the UK) But what speedos are people running? Is sensored or sensorless prefered in offroad? What would be the equivilent 'KV' rating to a '6.5' motor??

Would be most welcome to hear what set-ups people are running in their off road (2wd) cars & any hints/tips. Also how would gearing differ? I know that with my touring car the brushless could pull/required much higher gear ratios.

So many questions, thanks in advance for any input

Dan

[Brandon G]

IMO, 10.5 is the best balance for running in 2wd buggy. Seems anything faster just starts getting rediculous, and very hard to drive. But, of course, use your best judgement based on track type. Many times I have seen too much motor being more of a handicap than a benefit. I have always ran Noval GTB's and they perform flawlessly. LRP or Tekin would be my other choice. Get a sensored ESC whatever you do, they are much smoother throuhout the powerband. And yes, I have ran unsensored to be able to compare.

I run a 24/81 ratio in my 10.5 B4 and I run a 3600 orion Lipo. 3200 would be plenty and offer even more weight savings.

I run a 26/81 ratio in my stealth equipped 91 worlds RC10 with a 13.5. Same battery pack. At the moment, I can run faster laptimes with the 91 car due to it's smoothness and slight understeer/stability. I tried a 28/81 with this motor, but it was getting hotter than I was comfortable with. When I ran this car at the vonats, I was running 28/81 with a 17.5 motor.

[DerbyDan]

Thanks Brandon - thats great info!

Interesting to hear your advice regarding running milder motors - I completely agree that its often wiser to run a more docile car thats more driveable. My thinking behind running a 6.5 is that in my touring car the 13.5 is similar (if a bit more punchy) to running a 27t brushed... therefore a 10.5 would be like a 19t super stock brushed & hence a 6.5 would be like a mid/hot modified brushed motor - certainly thats how the different classes pan-out here in the UK. When I used to race off road before we used to run rediculous wind brushed motors - 8 singles etc But I guess our high grip (& draggy) grass tracks allowed these 'hot' motors to be driveable?..... Mmm, shame there doesn't seem to be an 8.5 brushless motor? [Edited; LRP do an 8.5 & a 7.5 in their latest motor range ]

My first experience of brushless motors was about 8 years ago - my sponsor (Modeltech [uk]) Started selling a brushless system that was effectively a sensorless model flight set up with revised software for the speedo. I drove a touring car with this in it & although the speed of the thing was like nothing else (I overtook a 3 speed IC serpent down the straight like it was standing still!) The driveability was pretty useless However the same speedo with a twin motor set-up in a Traxxas E-max was much better - as the vagueness of the big wheeled truck hid the ESC's lack of refinement. My thought was that a modern sensorless speedo would be ok in an off road buggy where the tyres are in less direct contact with the ground..... but it seems you have confirmed my suspicions that sensored is always better I've driven a couple of touring cars since that have been equipped with more modern sensorless ESCs but they still seem to just feel a bit odd

Thanks for the ratio info - i'm sure that will help give me an idea of where to start - whichever motor I decide to run

In fact I might aswell start off by trying my 13.5 I guess?

[Brandon G]

13.5 is a great 2wd buggy motor. I would run it against a 6.5 anyday. Remember, most straightaways only make up about than 1/10 of the whole track. If that's the only place you are being overtaken, I wouldn't sweat it too much. You'll get em back in the infield.

[vwjuice]

I agree with Brandon. Everyone here at our track runs 13.5. Anything bigger just sems to spin the tires.

A 17.5 is considered to be the same as a 27t brushed. 13.5 is the same as a 19t. 8.5 is closer to around a 12t brushed. 17.5/27t is considered the stock class in racing alot of tracks are limiting mod to 13.5 and nothing bigger.

[vwjuice]

Forgot to add that I run the lrp sphere tc esc and trinity duo 17.5 in my t4. I love the punch this esc provides. I have a novak ss esc with an Orion 17.5 in my b4. Should be a really good setup. Most people around here use the tekin pro setups. I guess they have a lot of adjustment in them.

[DerbyDan]

Thanks guys - some real food for thought

As it would appear I may already have a suitable system, in which to swap across from the touring car - I might aswell use that & see how the car goes first before commiting to buying new & expensive kit.