Improving rtr cars

[StuartH]

My son has an ecx boost which is a great learning car, it's stable and bullet proof and has excellent run time but is a little slow and I'd like to make it a little more racey for him.

We are currently running a 20t brushed motor with 1800/2000 nimh batteries. Does anybody recommend or notice a difference with the 15t stock motors? I say this because I ran 16x3 modified motor back in the 90s and it was a beast......even 27 single motors were fast!

Ideally I'm just looking for a simple setup to get him a bit more straight line speed. Tyres and springs are sorted. But I don't think the gearbox or drivetrain can handle brushless so that's out.

Any suggestions please?????

[Danny Harrison]

It will handle some brushless motors no problem.

Id buy a cheap brushless system between 10.5 and 13.5 turns.

That and a lipo battery and you'll be sorted. 30 min(ish) on a charge too

[emtee]

Hi, I hope what advice I can give is looked on as helpful and nothing else.. If I was looking to give the buggy a boost I'd go for lipo batteries, the weight(or lack of..!)compared to Nimh will give the car better top speed, increased acceleration and better run times on the motor you already run... As for BL motors, they are not all ballistic.. In fact I'd say with the lighter lipo cells you could go for a 13.5 and gear the buggy up a little, say 2-3 teeth greater on the pinion, this could help the pace and feel of the car...

[StuartH]

ok, i thought the plastic driveshafts might be melted by a brushless motor. i have a set of lipos and willl give them a go with the motor thats already in it.

whats the difference between the 15t stock motors and a 15t modified brushed motor? is there much noticable difference?

[Danny Harrison]

Originally Posted by StuartH

ok, i thought the plastic driveshafts might be melted by a brushless motor. i have a set of lipos and willl give them a go with the motor thats already in it.

whats the difference between the 15t stock motors and a 15t modified brushed motor? is there much noticable difference?

Be careful running lipo on your brushed speedo. It might not have a low voltage cutoff. Brand new motor n speedo can be had for under 60 quid now days.

[Dandare]

I had an ECX Boost for a while. Out of the box, using NiMh batteries it twisted the driveshaft ends so they kept popping out & then the diff threw a wobbly too.

I did install the upgrade metal geared diff & had to replace the driveshafts with modded Traxxas HD items, I then ran it without problems using 5000mah 30c lipos & a 15t HPI Firebolt motor.

I have to say I wasn't completely satisfied with it (self tap screws kept coming undone etc) but the above upgrades generally made it reliable.

[emtee]

Originally Posted by Danny Harrison

Be careful running lipo on your brushed speedo. It might not have a low voltage cutoff.

Yeh Danny is right, however, help is at hand! Have a look on an auction web site and search for lipo alarm.. Very cheap and reliable usually, it will let you know when the cells are getting near the safe cut off limit... Lipo don't like to go below @3v per cell, so in an average 2 cell(7.4v)the safe cut off is @6v.. An average lipo peaks out at around 8.4v max..

An average 13.5 BL motor will be around 3000-4000 rpm per volt(kva rating)so running on an average 7.4v lipo you should expect a no-load rpm of 7.4 x 3 - 4000rpm which is about 22000 - 30000rpm... I don't know how this compares with your 15t brushed but it used to be a 10.5 BL motor was about the same as a 19t brushed..

On a slightly different note, a mainstream brand I.e. Durango, associated, yokomo etc may be a better option if the quality of your ecx is in question?