Max amps are no better than any other pack. From what I hear people have had really bad luck with them. They have seriously inflated ratings. I've had great luck with my turnigy batteries. The perform just as well if not better than my smc packs. I would stick with the turnigys

+1 With Maxamps you're (over)paying for the name and all the advertising they do. The packs aren't any better than mid range packs. Thunder power used to be on the higher end, not sure where they fall now. But if you're going to buy higher priced Lipos look into Hyperion.

I can vouch for MaxAmps. Have an arsenal of both MaxAmps and Turnigy Nano-Techs, and the former just blows the competition away. The power to weight ratio on the MaxAmps are just fenomenal. You can run far less mAh and still have the same power delivery, which means you save a whole lot of weight. Less weight is higher performance. I love mine. Not to say the Nano-Techs are bad, they're just not in the same league. If I treat the Nano-Techs the way I treat my MaxAmps, they start to inflate.

Ok so since I created this thread ive achieved a few things, reached 112mph on 34/35, and found a pair of 37t pinions (yet to try) and I know kershaw makes 8mm mod 1 pinions from 15t -60t. That said I believe that I will max out the 2200 setup with a fingers crossed 120mph run. My next venture is leading toward a single 2028 on 8s geared to the moon, 39/35 or 43/35. I know it wont have the same rpm but it will have massive amounts of torque and with a HP figure of 10hp on 8s thats still more than twin 1480kv

Now how do you figure out the HP of the setup?

its what 746w = 1hp
Amp x V = W


Lets say I take 5000mAh battery, that equals 5amps correct? Then I multiply that with the Voltage of the battery. In this case an 8s, so 29.6v. 5Ah x 29.6v = 148w. Then what divide the 746w with the 148w? At this point im lost.

The idea is to find the most power for the cheapest route if that makes sense

I don't know how to figure out the HP of an electric motor but I can help with your battery math. Lipos are "capable" of delivering a certain amount of amps. The way you figure that out is multiplying the mah by the C rate. So for a 5000mah 30c pack you multiply 5 and 30 to get 150amps. That's what the pack is supposed to be capable of delivering, not what the pack will be putting out all the time. The motor is the amp draw, it may draw 100amps or it could draw 175 in which case you'd need better Lipos.

Now you could take the amps your Lipos are capable of and multiply by the voltage to see how many watts the packs are capable of. But you need to be careful here. As you know voltage drops under load so you need to predict that drop in order to figure out what wattage the Lipo is really capable of. I honestly wouldn't bother with all that. If you're going to do speed runs with a 2028 you want to get some 50c or better Lipos because that motor is going to put a pretty good load on the Lipos.

Also there's usually no need to figure out the wattage of a battery pack. The wattage a motor needs is fairly constant regardless of voltage. So you take the wattage of your motor and divide by the voltage you'll be running giving you the motor's amp draw. Now you pick your Lipos making sure they put out more than enough amps to supply the motor.

I figured on using the turnigy nano tech 8s 5000mAh 65c-130c with the 2028/XL2 combo

Yes, 1000watt equals 1.34hp (according to SAE). Here in Europe however we use DIN (Deutsches Institut für Normung), so 1000w equals 1.36hp then.

Calculating hp of an electric motor (within its efficient range) is simply amps times voltage. Unfortunately many companies, like Castle and Tekin, won't state the amp draw of their motors. Thus making good calculations becoming quite a challenge. Also there are different ways of presenting power in watts – the market for amplifiers is a good example. Based on data from the manufactures alone, it is often impossible to rank outputs. This is clearly the case with Castles Mamba Monster (120a) and Tekins RX8 (220a). The two unites are basically the same, yet rated very differently. Connected to a Neu motor with 180amps draw and both would burn up in a very short time.

What would be very useful then is a dyno readout of most available motors. Do you hear me Big Squid RC and RC Car Action ;)

Hmm so for the sake of argument then. The 2200kv which is rated at 120a then multiply that by my battery voltage of let's say 22.2v which equals 2664w then I divide that by 746w and I get 3.57hp. Times that by two and my set up makes 7.14hp. Granted there's drivetrain loss and other worldly restraints that lower that hp reading.

I guess the larger ampere the motor can handle as well as volts the more power.

Currently I've upgraded to two HW Pro 150a ESCs and two turnigy A spec 5000mAh 65c 6s lipos. I've pretty much maxed the blur ESCs out and now the connectors are coming loose on the boards. My next route will be two 1480 or slightly lower kv motors on 6s and see what happens. I think the new ESCs will help me reach 120mph I hope lol

Well I just told you such calculations ain’t worth much when comparing different manufacturers. You only fool yourself with those numbers and what’s the point of that? Following your analogy a Tekin T8 motor would draw 220a then. That is 6,55hp for each making a total output of 13hp. Way more than a Castle 2028 system – Go Tekin ;)

At best, what you just found is the performance of the Castle 1717 1580kv motor. According to Castle that motor is just about all the Mamba Monster esc can handle and therefore might be close to a 120a rating (Castle standards that is). The 2200kv motors in your setup is quite a lot weaker though. Don’t get me wrong here, your setup is impressive – but getting the numbers right is something else. Happily that is just calculations, what you are looking for is true performance. Generally larger motors draw more amps, and therefore a higher power output. Luckily there are a lot of options stepping up from the 40x75-size you currently use, as long as you are able to make the proper gearing. Twin 40x92 motors might be an excellent choice :)

As for drivetrain loss, voltage drop and so on is not of much relevance as long as the car stays the same along with the batteries (given they are dimensioned for the power system in question). That is the beauty of relative values :)

Can't wait to see your Savage rocket reaching 120mph!! Awesome built Skillet!

I get ya, it's just like the hp ratings on the box for nitro motors. There a joke and way wrong lol.

Since I went ahead a bought the HW ESCs I might as well max those out and later down the road I think I'll go with the leopard 1480kv motor both on 6s. Regardless I should see gains in mph, how much? Who knows lol. But I'll have more torque with relatively similar rpm range.

My dream is twin 2028's but thats just EXPENSIVE

120mph will be pretty epic :)

What lipos are you using on the 1717 motor? 6S?
I know the motor is rated by castle for 6s but can it take 7s or 8s and play on grass safe?

The Castle 1717 really shouldn't be run on anything less than 6s. It can be run on less but it feels lazy. I haven't done it but people have run the 1717 on 8s reliably. The only issue is on 8s theoretically the motor can go above its 45,000 rpm rating. This is only an issue on a fully charged 8s pack and if you give it full throttle with the wheels off the ground, otherwise the motor will never go above it's rpm limit.

A "safe" setup for motor temperature always depends on your particular vehicle setup. But my 1717 powered LST is geared for about 55mph and temps are fine wherever I run it.

Ive run my HPI 2200kv motor on 8s quite a bit and have reved it 65k @ 130mph and pulled 110k rpm blowing the rear tires up twice lol. I can say that running more volts through the motor is really only good for speed runs not bashing. My lastest test on 8s with bashing gearing you could clearly hear the motor over revving. There are plenty of guys who run 8s on the 1717.