mamba 4600 on 4s or 6900 on 3s? which is faster?
 

i decided i am going to go BL/lipo in my tc3 now. itll be a PURE speed machine. which of the 2 setups in the title will be faster?

4600rpm/V x 14,8V = 68080rpm
6900rpm/V x 11,1V = 76590rpm

=> The 6900 on 3S will spin faster.

Although the 4600/4s combo may tolerate higher gearing better since you're looking for high speeds only...

Both are over the max rpm of the motor, I would go with the higher voltage set up, may run a bit cooler.

yeah, thats what i was thinking. thanks guys. ill have it ordered within the month.

Pick the lower kv motor and gear up. I only dragrace with 5000kV motors and below. The higher kv motors just draw too many amps, dropping the voltage too low, making reaching the topend harder.

Just a thought - why not a 5700 on 4s A123 as a compromise - I think this is what stampedeproject was running...

I am running a TC4 I just finished. 4600 on 4S with 25/75...74mph!! Motor and ESC temps at 100 or so!!! It is a good setup for playing around. Easy 20 minutes on Apogee 3800's. I dropped in a 5700 to see what it will do Wednesday night.......

Funny thing, I did this setup once before with a Cyclone and junked it because the 4600 on 4S would melt the diffs after 2-3 runs!! Few months later, I help someone setup a bone stock HPI Sprint 2 w/ a 7700 on 3S with 33/81 gearing and WHAM, 84mph on the radar!!!!! SOOOO, I am back again to prove a point!!

Just an update: 5700 on 4S, 32/69.........84mph!!! Slowly climbing:yipi:

Do you have to use the mamba motors? The novak 3.5r went 79 mph one year at the worlds fastest rc-car challenge on just 2s. Last year the HV4.5 went over 100 mph on 4s and 118 on 5s. These were just off the shelf setups too.

I use to run 4s A123 with the 5700. It was silly fast, but heated up to quick.

You guys know that the 6900 should not be ran on 3s right? It is not made for that high of rpm, and will heat up very fast. Not a good idea imo.

Like PB said. Not only will it be dangerous and void the warranty it will heat up very quickly. Castle motors tend to do that...

You forgot that you are on the RCM forum. The peeps here are brushless experts.

I guess... I still wouldnt use Castle motors if your going for all out insanity.

But you are only seeing one part of the use for the motor. If the load is light enough heat won't be that much of an issue.

Last year the cheapo Mamba motors were used to break the 100mph barrier in 132 feet. I consider that all out insanity.

All I can say is that unless you have extensive knowledge on figuring out your load calcs for your car, then stick to the manufacturers recommendations. These motors are very capable for the money. However, you do have to know what your limits are or you can blow alot of money real quick!!

Yes, but when they tried to make a second pass, it blew!! Are you interested in a one shot deal or something fast AND reliable. Being involved in the hobby business, I have had much better outcome with Castle's stuff than Novak's. Also, Castle's equipment has alot more options and is cheaper than Novak's stuff!!:yes:

Where did you here that. That sounded like what happened to another setup. I heard the 4s setup w/ the hv4.5 ran all day without major problems.

From my understanding from some of the guys from the high-speed forums, there was more to the story......

Regardless, I am having zero problems so far with my MM setup.