Originally Posted by
Darin Jordan
So, I've had a chance over the last couple of weeks, using my IM31, with a stock 1800KV power system, but using a Castle ICE 100 ESC and an EagleTree real-time GPS system to record some data. Then switching back to the stock 80A ESC to do some "Torture Testing"...
Tested on both 4S and 6S.
The results... Pretty much every claim I've seen made on this forum concerning NOT being able to survive on 6S are simply false, or I'm just really, REALLY lucky, or really, REALLY good.... Or maybe both??
On 4S, the best I could muster with the stock prop was 33mph on 4S, and 43mph on 6S. To be expected. Blades are thick, unbalances, and not very sharp.
Swapping to a S&B version of this prop was worth a couple mph, up to 35 on 4S, and easily breaking 50mph (51.8) on 6S. Running the numbers on the prop would have predicted this, and it bears out.
Amp draw on 4S averages around 49A, with spikes to 59A.
Amp draw on 6S averages around 59A, with spikes to 98A, which are infrequent, but exist.
Switching back to the stock 80A esc, I ran the boat HARD through THREE 6S packs back to back, upping the prop size each time to overload the system, using the S&B stock prop, then an ABC 42x55 (GrimRacer 42x55 Revolt prop), then an ABC 45x55. Speeds were 50, 53, and 55 respectively, and the motor never got over 96 degrees. Also, as to the complaints (conveniently posted on the Horizon Hobby review site, I noticed) of the ESC not providing cutoff, etc... Again, this is false, or I'm just fortunate. Through all three 6S packs, and an additional two 4S packs, without making ANY other programming or other changes, the ESC ran and cutoff exactly where and when one would have expected. Shutting down, and then allowing a limp-home mode to get the boat back to shore. ESC never skipped a beat.
On 4S, with the stock system, swapping props to the Grimracer 42x55 (properly prepped) increased the stock speed to 39.5mph... I think 40+ is possible, and, frankly, propable, since my batteries were a little on the worn-out side.
After running the boat through three weekends worth of test sessons, testing two different 1800KV stock motors, two ESCs, and many props, on both 4S and 6S, I must say that this system holds up just fine to 4, 5, or 6S, and the ESC functions perfectly on 6S. I was even running the stock 4mm contacts the whole time.
The one weakpoint I would say is the wire size on the motors themselves. This seems a weak-point in the system, and will likely be addressed at some point.
One final thought... the boat is WAY more fun on 6S than on 4S!! :D After running several passes for top speed, I ran the boat lap after lap after lap at 44+mph and was simply a blast... boat just looks "right" at that speed!
OH, and in all this testing, I flipped only once, and submarined only once (my fault). My boat is setup extremely well, however. The ONLY change from a stock setup is that I have my own turn fins installed, which, frankly, make all the difference in the world.
Here are some of the data charts I recorded.... One the 6S "Speedrun" graph, that shows just two passes, please ignore the 65+mph spike on the second run... That would be the moment that the boat decided to leave the bindings of the waters surface and free itself from all of it's surface drag (flipped!)... Please note, however, that the boat, on both passes, exceeded 50+mph... This was with an all stock setup, and a properly sharpened and balanced stock prop (blades were thinned a bit too)...
Also, of note... when I was testing using 4S, running the boat as I had on 6S, then making just the SLIGHTEST trim-tab adjustment up to loosen up the boat a bit, was worth TWO MPH on top speed... Don't underestimate the benefits of having the right setup, and the performance increases that can be had by making the most minute fine-tuning adjustments.
Have fun!
Bookmarks