Optimum Brushless for high speed...

[motormania]

I have an interesting request...

I'm going to be racing a full size car in a PR stunt very soon and want to make sure I have the most powerful brushless for my 1:10 scale Xray Touring Car. I normally run a 13.5 stock brushless with my Novak GTB speedo.

What would be the best lipo/brushless combo to give me the fastest car possible...

[Holst]

How many cells can your speed controler handle?

Fitting two packs of cells in series will give you a substantial increase in power.

[Mikey G]

Not sure a Mamba Monster will fit in a touring car but my mate has the 2200kv system in his Losi 8T running 6S (over 22 volts) and lets just say its uncontrolable

Surely something like a 5.5 motor and maybe 3S Lipo would be a good fast combination but maybe still a little too fast....

[motormania]

I have to be careful that I can still control the car, this is for PR purposes and it's being filmed so I'm sure that there will be some 'artistic licence' used, but still want a quick car. I'm guessing, as the whole Brushless thing is still very new to me, that like Brushed motors, the smaller the number the faster the motor.

In other words, I currently run a 13.5 stock brushless, but if I use a 5.5 that'll be much much faster right?

I can probably get away with just a high capacity 7.2v lipo. I'll get a couple so one can be on charge while we film using the other.

I have a Novak GTB speedo that came with my Novak 13.5, will that handle a faster motor, or will I need to upgrade the speedo to run the super fast brushless?

[Mikey G]

Well the GTB is available in a combo down to a 3.5 motor so should handle it nicely. You will only need to change the motor so wont need the expense of another speedo setup.
With brushless you tend to double the turns to give you the brushed equivalant, i.e. your 13.5T is the same as a 27T brushed, but the brushless will still outperform the brushed everytime.

That controller wont take more than 2S Lipo anyway as that would give you a nice increase in speed without having to change anything apart from the battery.

[motormania]

Thanks for the feedback, looks like a couple of higher capacity Lipos and a faster brushless is the order of the day

[Mikey G]

Make sure you check the discharge rates, pointless having a 5000mah battery if its only 15 to 20C discharge. You want something that can push the power out when needed. For example a 3800mah 30C battery will give out more instant power than a 5000mah 20C pack.

[Holst]

Mikey G said:

Make sure you check the discharge rates, pointless having a 5000mah battery if its only 15 to 20C discharge. You want something that can push the power out when needed. For example a 3800mah 30C battery will give out more instant power than a 5000mah 20C pack.

I think for this sort of thing capacity is unimportant (unless they are going to ask you to make multple runs)

Fit as many cells as your ESC will allow at the highest C rating that is economic and dont worry very much about the capacity.

[Mikey G]

Holst said:

Mikey G said:

Make sure you check the discharge rates, pointless having a 5000mah battery if its only 15 to 20C discharge. You want something that can push the power out when needed. For example a 3800mah 30C battery will give out more instant power than a 5000mah 20C pack.

I think for this sort of thing capacity is unimportant (unless they are going to ask you to make multple runs)

Fit as many cells as your ESC will allow at the highest C rating that is economic and dont worry very much about the capacity.

Yes, i think thats the point i'm trying to make. Just remember C rating is the capacity so a battery with a 20C rating will discharge at 20 times its capacity, so the higher the capacity the higher the potential discharge rate but only if the cells allow it. Using my example above the 3800mah 30C battery will discharge @ 114amps but the 5000mah 20C pack will only output 100amps. But if you find a 5000mah 30C pack then it has the potential to output 150amps in one swoop.

So motor and battery choice will play a big part, no point in the more powerfull motor if the cells cant supply enough to use it all, and again why spend money on a big battery if the motor only demands half its output.

There are other tricks to get more out of a Lipo but they are dangerous and involve overcharging them to a higher voltage. This will give you more speed though.

Your speedo will also be programmable so you may get a little more control of the bigger motor by altering the settings.

Take a look on the oople.com forums for more advise and someone may give you exact advise on motor/speedo/battery combinations they use.