Troubling observations about brushless . . .

[rdbruski]

The power of brushless in a toy sized package is a wonderful thing. While watching videos of brushless trucks, I'll admit, I have a grin on my face the whole time. :D I plan on converting my T-maxx 3.3 to brushless. However, a little bit of the infatuation is wearing off about brushless and I'm seeing things a different way now.

Virtually ALL the videos I've seen shows the awesome power of a brushless truck with its front wheels off the ground most of the time and many times the truck on its tail or back and out of control. At first, the power monger in me wants to build a powerful monster brushless truck with all that power. On the other hand, I remember how fun my T-maxx 3.3 nitro was when I had it running. The front end rarely came off the ground and all 4 wheels were down, steering and in control. It didn't have the speed or torque the brushless trucks have, but you could actually bash and steer with it which to me is more fun! I've only seen maybe 1-2 video's out of DOZENS where a brushless guy is actually playing with his truck in a way it is actually in control and having fun.

To me, the overpowered brushless trucks do not look fun at all. I plan on playing with my brushless T-maxx with my young son. From what I've seen, he'd not have the dexterity to run a brushless, much less me.

Can you help me understand what I can do to go brushless with my T-maxx but still make it be fun?

From what I've read, there are several factors producing this out-of-control scenario. Tell me if I have this right . . . 1) Over powerful battery/motor combination for the weight of the truck. 2) Poor front end weight dynamics. 3) Incorrect gear ratios. 4) No chassis tilt.

1 - I understand the wheel popping is from the massive torque from brushless motors. Are people just buying over large batteries/motors supplying too much torque?

2 - Wouldn't added front end weight help to keep the nose down? How about mounting the batteries in the front? I have an RC Solutions roll cage, so battery damage won't be an issue for me.

3 - I know gearing can have an impact. Wouldn't you want a gearing strategy to produce less low end torque to keep the front on the ground?


4- On my T-maxx 3.3, I bought some really nice Nova RC shock towers and the Big Bore shocks. I mounted the shocks in the back so that the back was considerably higher. Then, when I'd take off, the back end would squat down as normal, but instead of lifting the front end, it now would run level. Is this a good strategy for brushless power also?

Wouldn't these changes be better on the drivetrain also?

Have I just removed all the benefits of lipo by engineering them back out?

I have to believe there is a way to have the power of brushless, but keep the wheels on the ground and your truck in control.

Let me know what you think.

[sapper_triple6]

I cant give you any advice on the set up part of things, but all I do is bash and it is a blast with BL power. I also have a 3.3 Revo and it doesnt compare with the BL Maxx. Check out my youtube vids. Great fun and in control.

[suicideneil]

Easy, the trucks are over powered! The fact is in a racing situation full throttle is rarely ever used for more than a few seconds, so the wheelying problem doesnt manifest itself very often. The torque/ gearing issues arent easily addressed with the current BL line of motors available- go too small and they over heat trying to propel the truck, go XL and they have too much torque almost. Gearing up for more speed/less torque is a no-no, since overgearing is what kills the motor/speedo/batteries, believe me. When you see the vids on youtube of trucks wheelying down the street etc its mainly 'showing off', demonstrating the power of the setup; you would never see that happening in a race. As for batteries, they can never be overpowered as such. The more MAh capacidt the better, and voltage ratings is just a case of matching the volts required by the motor- you cant have too many volts since the esc/motor wont take it & will blow up. If you want a fast but controllable system for you & your son, I would suggest the HvMaxx 6.5. It is a very sturdy system, very simple to set up and is 99% bullet proof- you rarely hear about blown escs/motors, and when you do its usually bad from the get-go, not as a result of just using it normally. I love my HvMaxx, and although it lacks torque (which make it wheely), it is still fast and with the correct gearing of about 25-30:1 it easily does 35mph+ with 12 cells in a 12lb truck. None too shabby I would say....

[IBJAMMIN]

The main diference between brushless and nitro is the power curve a nitro motor builds power with RPM where a brushless motor can have almost full power at any given RPM the nice thing with the Mamba ESC's is you can go in and change and manipulate the throttle curve on your computer to mellow it out and make the car more controlable and easier to drive this also helps extend the life of the diff's and gears by reducing the power at lower RPM's. It's a lot easier to detune the power and have it where you need it then wish you had more?:017:

[suicideneil]

^^ True that. A 10xl on the MM with 12/14 nimh would be great- the more winds the slower the motor on the same number of volts. The advantage being you can always get a quicker motor later to go faster, as you get used to the speed/torque. The MM will only safely do 14cells with a ubec.

[zeropointbug]

I plug my ears!!! :019:

Yes, the main difference between nitro and brushless power is well, the torque curve.

A 'watts' or 'hp' rating is meaningless without knowing what the torque is like.

And engine has a narrow usable torque band as far as amount torque over a specified rpm range, where as a brushless motor has maximum torque at zero rpm and naturally drops off from there, but still has plenty of torque up higher in the rpm range where they would get the 'power' rating from. Do you understand?

As far as too much power, "forget about it!"


Another reason brushless is much faster than nitro is throttle response, instant torque delivery, unlike nitro where there is quite a delay in responsiveness. You know what this means.

Just run the amount of cells you want in a truck and that will limit the power, and thus the drivability, and still be able to run circles around nitro trucks.

[MetalMan]

Many people who drive around brushless trucks do wheelies because they can/enjoy doing it. If this isn't for you, then a center diff is for you. In my Revo I'm running a 1/8 center diff with 30k oil, and using it diffs out to the front, but occasionally I'll get a bit of a wheelie. Of course, the instant power can be tamed through settings on the speed control (depending on the speed control), so it's not at all hard to keep the front tires on the ground at all times.

Throttle control is the name of the game. My 8 year old son drives our Monster GT conversion and has adapted well to it. He can make it wheelie on demand, but also doesn't have any trouble keeping it on all fours either.

It isn't necessary to add any weight. In fact, I've found that it doesn't help. It just makes the truck handle like a tank.

Go with a moderate setup, like a mamba max with a 10XL. It's still going to wheelie, but won't be as outrageous and some other setups.

Just because your car can do 140, doesn't mean that you'll do that all of the time. It is nice to know that you can though.