Too slow. I read up about the rather amazing HvMaxx/ Fiegao experiment and it seems whilstt it worked, the HvMaxx needs a bit of work done to handle the higher temps caused by running a hot motor such as a 7xl. The sensored fiegos are rather cool, but hard too get hold of (just a pic on their site, special order only which is a shame & hassle since I would like a selection to chose from, rather than guessing at specs). Something to look forward to in the future, although a 5/6s Velineon would seem like the most ideal solution to running sensored/sensorless Bl motors. Bring it on Traxxas, before anyone else beats you to it and gets my money first!

The HvMaxx esc is very capable, and if you swapped over the cap for a 35v low esr version (or 2 or 3), and added a bit of meat to some areas of the pcb traces inside, it will easily do 16 cells, maybe more. I would love to get hold of a setup on ebay for dirt cheap (say someone broke their truck and wanted rid, or snapped the motor shaft etc), then i could have a play without fear of killing my only system....

I thought I just said that the novak motors (at least the ones with the sintered rotors) don't have overheating issues and the feigaos do. Also I never denied the fact that the feigao xl motors are more powerful. My point was efficiency. The feigao motors have a wide gearing range but, there isn't a gear ratio that doesn't create heat. The novak motors heat up only when they are overgeared. All you have to do to fix the torque problem w/ the novak motors is GEAR LOWER. Since a hv4.5 has more than twice the kv as an 8xl, there's a lot of rpm ot spare. Before you fire back at me at how lower rpms are more efficient. I'm still willing to bet that a novak motor spinning at 60,000 rpm is more efficient than a feigao motor spinning at 35,000 rpm. Plus the design is completely different so their "sweet spots" are at different rpms. Also, what are you using to get a 50 mph 4s powered monster, whose motor DOES NOT overheat and is not a neu or a lehner. I hope you are not referring to the 8xl, because I've never heard of a motor that pulls 11:1 FDR's in a monster truck, because that's what it would take using 6.5" tall tires. I apologize if I sounded harsh.

Harsh no, just annoyed. I have to agree with you; the Hvmaxx does have a high KV rating (4800 or 4400 models), but then thats the way Novak designed it to be. The trouble here is I think people are trying to compare apples and oranges (I hate that expression but its handy). Example:

An Airel Atom only has a bike engine in the back, yet can do 140mph+ because its light. A Ferrari has a much more powerful car engine under the bonnet, and can do 180mph+

The point here is the smaller bike engine makes its power with high revs, which allows it to propel the Atom to a very respectable speed. The Ferrari however uses a much larger engine with lower revs to make its power & speed the car along. Now think about the HVMaxx & Feigaos/ lehners etc.... You see my point?

Incidently:

Differential Ratio: 2.8461538461538462
Transmission Ratio: 2.769230769230769
Other Ratio: 1
Spur Tooth Count: 66
Pinion Tooth Count: 17
Total Voltage: 14.4
Motor KV: 4400
Tire Diameter (inches): 6.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 3.88 : 1
Total Ratio: 30.59937 : 1
Tire Circumference (inches): 20.42 inches (518.68mm)
Total Motor Speed: 63360 RPM
Vehicle Speed: 40.04 MPH (64.32km/h)
Effective Speed Rate: 2.78mph/V (4.47kmh/V)
Effective KV Value: 4400

This is my current setup- I am going to the park tomorrow since the weather is ment to be very good- video will follow.

EDIT: Because ZPB is a car/bike geek, and caught me out....

speedybl; please tell me; Did you ever HAD an XL which you tested at different gearing ratio's?

I used to run an 8XL in a savage locked in 2nd gear, on 16 cells and it barely got warm after two batterypacks.

I have got a hvmaxx laying here, perhaps i can upgrade it with a new rotor and report back, but on the other hand; i'm not too keen on the 3.2mm shafts, and the high kv isn't my bag..

what temps and what speeds are you getting from your hvmaxx?

When I posted initially, I was referring to what I have read over the past two years. I have never actually driven either an 8xl or hv. Also, im refering to the HV4.5 (4.5 turns), not the 4400 which is 6.5 turns and only actually has about 3100 kv.

Hv4.5 = 4800kv
HV4400 = 4400kv
Hv6.5 = 3100kv

I believe using the 6.5 would be an ideal solution to heat issues, since it has a lower kv rating & more torque than the others, so a greater input voltage could be used to generate the rpms, rather than a higher kv motor which draws more current = heat. I will have to wait until I get my new setup in a few months to compare the two systems, but each system has its own merrits.

I wonder if it would be worth it to compare all three motors on one ESC. Of course, it would have to be a sensorless ESC to compare the XL motor...

I dont think it works that way. Power is power. Rpm is one component of power and torque is the other. Unless you are reaching the mechanical limits of the motor, gearing is used to compensate one for the other and that's all that matters. The 4.5 is more powerful than the 6.5, meaning its more efficient at higher currents. Of course the 6.5 will run cooler, but that's just because its a slower motor. For instance, the 6.5 might run cooler when geared to go less than say 30-35 mph, but for any speeds greater than that, the 4.5 will run cooler. Also, I assure you that the hv4400 does not have 4400 kv. The ss5800 definately didn't have 5800 kv. In fact it was more like 4200 geared high. Honestly I don't know how novak came up with those original numbers. The numbers they supply now seem to be correct. They now list the ss5800's kv as 5000kv, which seems right for an unloaded value.

You know, I'm pretty sure I click 'submit reply'

That's the best way to answer the question. Of course we need a non biased opinion too and actual radar testings would be best.

Sorry for being a pain, but I couldn't help it.
The Ariel Atom has a Honda Civic Type R engine in it and the faster version is supercharged, but yes the Honda engines rev pretty high.
Most Ferrari engines make most of there horsepower and torque at high rpm so I'd say the xl's are a bit more like a big V8 chev or something.
I know what your saying about the HVMaxx compared to xl's and other low kv high torque motors and I kind of agree. But also the e-maxx isn't a light car, you can put a V8 in a big pick up truck, but you wouldn't put the honda civic engine in it. For reliability and fuel economy heavy vehicles usually use big engines with torque rather than small engines with rpm.
Personally I like my 1700kv neu 1515, but I'm not trying to say the novak's aren't that good, because I haven't seen them run. If you get it running so your happy with it then that's what's important.

That Atoms in the States use GM Ecotecs.

Oh, I didn't know that. What size engines are they 2L, 2.2L?

They are supercharged 2.0l versions. Brammo sells them over here. They also have some neat projects of their own. You should check them out if your into 1:1 scale toys too.

Hmmm, that's what I meant when i said "I was sure I clicked 'submit reply'"


Someone with the power thinks my comments aren't worth it...