I'm stuck there are to many options but not enough money lol. I think the flux torque only spins to 50k while the castle version is good to 60k. The 2650 can spin higher than the 2200 but lacks some torque. The 1717 has less rpm but a lot more torque and the 2028 is boarder line to much torque

I can pick up the castle version of the 2200 for $105 x2 and a whole 2028/ XL2 combo for $360, and the 2650 for $135 x2. But in order to run 8s for the 2028 I would have to buy matching 2s lipos for my 6s I already have.

Lol I just don't know

Isn't the 2028 like 800kv??

On 8s you'd be looking at ~23k rpm..

With a 1717 on 8s you'd be at ~46k rpm which sounds like where you need to be.

how do you guys figure out these rpm figures?

Battery voltage multiplied by kv. I use resting voltage, so 3.7v per cell x 8 cells = 29.6v. Multiply that by the kv and you get the unloaded rpm at that voltage.

sorry for the questions but what is resting voltage? why wouldnt you use a full charge?

Compensating for voltage droop, Under load. constant load your battery doesn't sit at full 4.2v a cell, the voltage will sag from fully charged when its being depleted.

I don't use a full charge because at a high amp draw, the batteries usually drop voltage. Again, we're talked unloaded kv as well. Loaded kv will change with weight/gearing/load.

I see, well I learned something new tonight

I think youd be better off running one larger motor. Even one of those can produce insane amounts of power! But I think Kershaw Designs or RC Monster makes things to run big ol beer can sized motors! Sounds bad azz though!

The motors free reved might hit those rpm, when i calculate rpm i use battery voltage of 3v/cell. If anyone does speed runs you will see the volts drop that low during a run. I have seen a video of a castle 2200 on 10s before. Also the gearing you are running should hold the rpm back also.

I know with nitro the taller the gearing the less rpm, so that's the same here with BL?
How would you figure out the rpm I'm running right now?

LL check this out

http://scriptasylum.com/rc_speed/top_speed.html

At 3.4v on 6s with 34/35 gearing it has me at 44k rpm @ 167mph with 4.15" tires.

I did use much higher volts per cell in my calculations to be overly cautious as far as rpm potential. It's been awhile since I've seen any Eagletree graphs, let alone of a high draw setup (I miss that about RC-Monster) but I'm still surprised the voltage would drop that low. Sounds like boat territory where 2p (parallel) is needed to keep the voltage from dropping too much under load. Although running a higher voltage to start with will lower amp draw and keep the voltage higher. 10s on a Castle 2200? Really? I would've thought the windings couldn't take it for long and self destruct after a few passes. I still wouldn't bash that setup though!

What about upgrading to a better battery like Max amps or thunder power instead of the turnigy nanotechs im running?