Mamba Max motor possible mis-labeled?

[coolhandcountry]

Did you program the esc to the controller?
Even if the epa is 100% don't mean you getting 100%. What if you go 125?

[phildogg]

Originally Posted by coolhandcountry

Did you program the esc to the controller?
Even if the epa is 100% don't mean you getting 100%. What if you go 125?

does it matter to an esc if you have epa set at 100% compared to 125%? I have never thought of this.. just wondering I looked my radio is on 100% now.. would it make a differance to set it at 125% and reprogram the esc ?lmk
phil

[captain harlock]

I have to say that putting a 7700 Mamba motor in a Jato, even if it's a 1/10 nitro car, is an impulsive attempt for hi speeds.

First, the Jatos are quite heavy( in comparison to a T4) due to the metal chassis the components are sitting on.

Secondly, some of the GP3300 batts are of low quality and they have a very high internal resistance which might deteriorate the performance of the motor.

Thirdly, the Mamba Max motor's diameter, though the cans are 540 size, is not of the same size as the other real 540 sized motors such as the Lehner 1920 and the Hacker B50( meaning less torque). Not to mention that the KV is very high even when using a 7.2V pack. You are almost near 60000rpm, which is not good for the motor's effeciency and that is the reason behind the high temp of the motor.

Fourthly, GP3300 packs, the good ones, can give around 35amps of discharge which is veeeeery low for an amp hungry motor. The 7700 can easily suck 90amps out of your batts which they can't afford.

To provide a good amp feeding to the motor, I humbly suggest high discharge rated, high quality lipo packs.

Team Orion has the very good 4700mah pack with loads of power.

Even better, is the TrakPower lipo sold by FlightPower.

Both of those packs come in hard cases with very good numbers of amp discharging and run time.

[BrianG]

Originally Posted by phildogg

does it matter to an esc if you have epa set at 100% compared to 125%? I have never thought of this.. just wondering I looked my radio is on 100% now.. would it make a differance to set it at 125% and reprogram the esc ?lmk
phil

Make sure forward and reverse are set to 100% or more. If the reverse was set to, say, 25%, the ESC might think neutral is somewhere between neutral and full throttle and may not program right.

[SpEEdyBL]

This thread is really mixed up:

First of all a 7700 on any fully charged 7.2 volt battery will make the tires balloon out of control when lifted in the air. It doesn't take that much power to do so, just a lot of rpm. Unless your EPA is not set correctly, you must have a mislabled motor.

2. High kv motors do not have less torque than lower kv motors. Torque is a function of amps which are mostly limited by the battery.

3. The fastest setup would be the 4600 on 4s lipo and U-bec. You will easily be able to beat a stock jato with this setup. Even the 5700 on 3s will be able to beat a jato, though it might overheat.

4. The 4600 on 4s is most likely faster than a 7700 on 3s despite the rpm difference.

[coolhandcountry]

Do you have any kind of limiter on the radio to?
I think you should call castle. It don't sound like you got a 7700 or
it is running like it should.

[glassdoctor]

That's why I asked if hte tires would balloon... trying to tell if its' slow because it's way overgeared, or if it's just not hitting a descent rpm. Yes, the tries should balloon way up on 7.2v and they should about come off the rims on 14V

So something ain't right.

If the esc is programmed with the radio at 100%, it won't matter if you set it to 125% and re-program it. It should be exactly the same.

Just check the leds on the esc as see if it's hitting full throttle... shoudl be a (green?) led light up at full throttle.

[sleebus.jones]

Yup, solid green indicates full throttle.

Sleeb

Its easily possible the truck was so overgeared the ESC smoked the high end FETs and will no longer reach over 1/2 throttle roughly. Any motor would balloon the tires, a 19t would. I would bet the batteries are poor quality for the application, which adds to the problem.

Forget about it being "mislabelled" thats not something that happened if you bought it new.

[pinolelst]

Originally Posted by Bomb-Proof

Forget about it being "mislabelled" thats not something that happened if you bought it new.

It's happened on other brands...Neu motors for instance recently had a couple mislabelled motors...said 2.5 turns on the wiring but the label said 3.5 turns for instance

pinolelst

[Serum]

where people work, mistakes are made..

How is your GP3300 pack configured? is it inline or side by side? if they are inline, are you sure they are soldered?

[MetalMan]

Serum, here's the answer to your question:
http://www.rc-monster.com/forum/show...59&postcount=5

[Serum]

thanks Metal.

That doesn't explain.. (the side by side thing)

[coolhandcountry]

Side by side packs. He said it.

[SpEEdyBL]

Here's an easy test:

Attach a voltmeter to the battery and run the car in the air to see how much the voltage drops.