speed gear

[golodo]

hi, I wants to run faster with my boss but I don't wants to run 2 batterie in series because of the esc problem. I have 2 Nimh and 1 Lipo 2s. I'm planning of put the high speed gear that came with the car but I'm not sure if it's a good idea. I wants to know whats are the best setup to run faster and if a 3s is less agressive than two nimh in serie.

Please leave your idea

Thanks and sorry for the english....

[Jimmie Neutron]

The high speed gear will actually make the car go slower if it is fed the same voltage.

What gearing do you have now?
(there are usually numbers on the pinion/spur gears)

[BigFlash]

to Jimmie
According to my rally vxl manual stock is 28/45 and high speed is 31/45. I'm not sure if you mean that it will be slower in that it just won't have the power to reach full speed or if your thinking about the Merv where the high speed pinion is smaller than normal?

lipo is better than nimh in power and run time. So with a 3s lipo it's might be slightly slower initially than nimh in series but the nimhs will loose power much quicker while lipos have much more consistent power. For high speed runs 3s is the way to go but the chance of breaking things is greater.

[Jimmie Neutron]

Yes, I was thinking about the MERV... its "speed" pinion is smaller than the installed pinion.

He should be fine with 2S and 31/45...
depending on the temps when running 28/45.

[golodo]

Now I'm running 28/45 and I don't understand what you are talking about what is de Merv and why I will run slower with 1 nimh and the 31 tooth gear?

[Jimmie Neutron]

The MERV is a nick-name for the Mini Revo.
The speed pinion in the MERV has 23 tooth.
The installed pinion for the MERV is 28 tooth.
They have the 23 tooth pinion for running batteries in series.

What are your temperatures when running 28/45?

[golodo]

You mean esc and motor? I never mesure it but after running the two nimh in para it's hot not burning but hot

[Jimmie Neutron]

When you want to change the gearing of an RC, you need to know the current temperatures of your motor and ESC. Your finger is not accurate enough... a temperature gun is necessary equipment and can be bought for around $10-15.

You see, the motor is fine up to 200°.
Your finger feels anything around 140° and up as too hot.

If you are already at 180° and you gear it more aggressively for more speed, you will fry your motor.

[golodo]

Ok thanks so tomorrow I will buy one and mesure the temperatures and I will post it

[Jimmie Neutron]

Thank you!

All temperatures listed above are in Fahrenheit.

[golodo]

Yesterday I mesure my temperatures and it was: 100° or 110°
After that I put the 31t gear and mesure the temperatures like 3 times during the run and it was no more than 120°
I was with a friend and he got a MERV and his temperatures was 130° or 140° with stock gearing and 2s lipo, so I think theres no problem to put the high speed gear with 2s lipo and it goes juste a bit faster with the same low torque.
Thanks for help