F103rs motor/lipo options 2s or 3s?

[GavvyD 1]

Hi all.

Have just purchased an F103rs chassis with a hobbywing 1060 esc installed.

What would be the difference/pro's & cons of running a 15t brushed motor with 2s lipo compared to a 21t with 3s lipo?

Also any tips on gearing would really help me out

Cheers

Gav 

 

[Jonathon Gillham 4605]

The F103 doesn't need much power to go fast. My sons runs a silvercan on nicd (yes, nicd, 1400mah racing pack from the 90s) and it goes pretty well. I run 21.5T on 2S lipo in my TRF102 and that is fast enough. If you haven't driven an F1 car before it will take a lot of getting used to.

With motors, more volts mean more rpm, so a 3S lipo will give roughly 50% more rpm and therefore top speed in an F1, give or take physics and friction and stuff. What are those motors you're looking at? If they are ebay cheapies then they're probably not that great. I suspect a Super Stock RZ 23T will outperform them and be plenty fast on 2S. I have no idea if the Super Stock motors can handle 3S. They are plenty fast in my Top Force on 2S though

Gearing the F103 is straightforward as its direct drive, so the FDR is just spur / pinion. You can go a lot more aggressive on the gearing as they are so light, and of course very efficient with no gears, shafts or belts to sap power. I swap mine to 48p to get a much bigger range of gears. I think I run something like 72t spur and 27t pinion for a 21.5T brushless motor.

[GavvyD 1]

Hi thanks for the reply.

The motor i have coming to me in the post is an Absima Thrust eco 15T,which i believe runs at 32,000rpm(Brushed)

https://wheelspinmodels.co.uk/i/211970/

The battery i have gone for is an Overlander Ultrasport 2700mAh 2S 7.4v 50C LiPo (Deans)

https://wheelspinmodels.co.uk/i/305383/

As i mentioned before,this will hooked up to a Hobbywing 1060 quicrun esc

 

[Jonathon Gillham 4605]

14 hours ago, GavvyD said:

Hi thanks for the reply.

The motor i have coming to me in the post is an Absima Thrust eco 15T,which i believe runs at 32,000rpm(Brushed)

https://wheelspinmodels.co.uk/i/211970/

The battery i have gone for is an Overlander Ultrasport 2700mAh 2S 7.4v 50C LiPo (Deans)

https://wheelspinmodels.co.uk/i/305383/

As i mentioned before,this will hooked up to a Hobbywing 1060 quicrun esc

 

That will work well. It doesn't give torque figures but 32000rpm is heaps. The Super Stock RZ is 27,500rpm, but pretty torquey.

Is that battery a hardcase? Hardcase are safer in a crash...

[GavvyD 1]

Hi Jonathon.Yeah,should go pretty well!

I know brushed motors,especially those running at a higher rpm don't last too long,but at under £9 a pop i though badword why not,i'll just buy another if it only lasts a dozen runs or so.i will only be running it once a week as a bit of fun,not racing or anything,purely just for leisure👍

Battery isnt a hardcase,but to prevent "incidents" i will be running it in a massive open car-park after closing time well away from kerbs and the like.Will invest in a hardcase lipo in time though👍

[GooneyBird 938]

Keep in mind that the ball diffs on an F103 can only take so much power (torque, not RPMs) before slipping. Tightening them up further will temporarily fix the issue but will only result in a lot of going backwards in corners and broken diff cups. 

Really with an F1-style car, a 21.5t on 2s is MORE than enough. Especially outdoors, where grip might be sub-optimale. I've run an F1 car on foam tires on carpet indoors on a 17.5t, and that's about as fast as I'm able to drive something. 

[Fabia130vRS 2098]

3s on brushed motors I would not try at all. I would bet on burning out the motor very fast.

 

 

[Jonathon Gillham 4605]

23 hours ago, GooneyBird said:

Really with an F1-style car, a 21.5t on 2s is MORE than enough. Especially outdoors, where grip might be sub-optimale. I've run an F1 car on foam tires on carpet indoors on a 17.5t, and that's about as fast as I'm able to drive something. 

Haha, not many people admit that the car is faster than them!  The number of people I see running mod classes, or Pro10/12 who really shouldn't be...

There is a problem now that 21.5T is actually really fast, not much slower than 13.5T.  I think clubs need to look at 25.5T motors for their stock classes now.  I think in the US they run 25.5T in F1 and also have USGT and VTA, one of which is 25.5T too.

After 3 years of 17.5T blinky buggy racing I think I could run 4wd mod pretty well, but not 2wd mod, I'd just spin more.