IM31 Tortue Testing and results - Totally Refuting any claims that 6S won't work!

[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!

[Fluid]

Darin, while your testing certainly confirms what you tested - you were running laps around a long defined course (or at least it seems so from the logs). Running consistant laps at constant throttle is usually easier on equipment than making tight turns, slowing down to a near stop than hitting the throttle, etc. Many (most?) sport boaters will run the latter way, not on a race course. Too, you used reasonably sized props for the type of running you tested - many sport boaters will go to more aggressive props which are neither thinned (nor balanced in some cases). And 96*F on the motor may not seem bad on a 45*F day in February - but try it again on a 105*F day in July....

I am not arguing with what you say as far as your testing goes. And I have never said that 6S would not work with this setup - but an 1800 Kv motor on 6S is much more sensitive to prop changes than the same motor is on 4S. Just because it works does not mean that everyone should use it, which is one implication of your post. You are among the more experienced boaters who know how not to burn down a boat. Beginners starting out can - and will - get into more trouble running this setup on 6S before they learn what not to do. I would caution those who try this in the summer on a small pond to watch carefully for high temperatures and consider limiting their run times to shorter than LVC.


.

[Darin Jordan]

Darin, while your testing certainly confirms what you tested - you were running laps around a long defined course (or at least it seems so from the logs). Running consistant laps at constant throttle is usually easier on equipment than making tight turns, slowing down to a near stop than hitting the throttle, etc. Many (most?) sport boaters will run the latter way, not on a race course. Too, you used reasonably sized props for the type of running you tested - many sport boaters will go to more aggressive props which are neither thinned (nor balanced in some cases). And 96*F on the motor may not seem bad on a 45*F day in February - but try it again on a 105*F day in July....

I am not arguing with what you say as far as your testing goes. And I have never said that 6S would not work with this setup - but an 1800 Kv motor on 6S is much more sensitive to prop changes than the same motor is on 4S. Just because it works does not mean that everyone should use it, which is one implication of your post. You are among the more experienced boaters who know how not to burn down a boat. Beginners starting out can - and will - get into more trouble running this setup on 6S before they learn what not to do. I would caution those who try this in the summer on a small pond to watch carefully for high temperatures and consider limiting their run times to shorter than LVC.


.

Jay, I agree with most of what you said there, except the "defined course" part... During the full stock setup torture testing, I have entire runs that were done with my 11 year old daughter driving... on and off and turn and slow and fast and loaded and unloaded.... Pretty much like what a "beginner" would do... We weren't on a "race course", by the way... just out at the boat launch, running back and forth around an imaginary course. That's why the corning speeds drop off so much.

Now... all that said, you are right... I did use reasonable props, but that's exactly part of the point of this was to show that you don't HAVE to go crazy to get the performance, and it's about more than advertised prop "pitch"... What people do beyond what a proven system is up to them, and their risks to take.

And, I also agree about the hotter day part... no doubt, the 49 degree weather in the 50-degree water didn't hurt.

I also wanted to fully test the claims that the LVC didn't work (see other thread and the review on the 80A ESC on the Horizon sight)... It does. However, this is honestly the very first time I've EVER run a boat down that far. Like you, I know the limits and really don't like to take my packs down that far. But, in the name of "science", I needed to risk it this time.

OH, and I would LOVE to have a chance to test on a 96 or 100 degree day... It's FREEZING HERE!! :)

To those reading... Listen to Jay here. He's right. Be careful, and build up to this stuff.... I didn't get there by unpacking the boat and going running. This boat has been fine tuned to a T, and, with the batteries properly placed, only needs very SLIGHT adjustments in the trim-tabs to dial in the handling for a particular day or water conditions... Learn your setups...

[mannytx1]

Impulse 31 v2 improved
test in summer 2012, in Texas with more than 100f

The problem was the color. I change the color and no more problems LOL…..

-Battery 5S 4000 mAh 40C
-Propeller (Battery 5S, motor timing LOW)
42x55 45.4 mph
M445 46.3 mph
42x55 the tongue removed 47.2 mph (timing high 8% more speed and Amp)
M445 reduced to 42mm diameter 50.8 mph (timing high 8% more speed and Amp)
-Cooling hose 1/4x .170 O.DxI.D
-Connector 4mm Gold battery
-Connectors 5.5mm bullets
-ESC front, more weight to the front, batteries more near the CG
-CG 30 % 8” ¾ or 9”
-Improves cooling system
-The antenna of de other side
-Reinforcement of the hull and hatch cover with fiberglass and resin
-Modify the original turn fins
- flex shaft (Miss Geico)
-Adjustable trim tabs
-Homemade bushing
-Hatch lock
-The stock 1800KV motor and ESC 80 Amp (only 5s)
-weight of the boat 4 ½ pounds without battery, with battery 5 ¼ pounds
Manny

[mannytx1]

100_0269.jpg100_0270.jpg

Can someone explain why? Impulse31 v2, is faster with the engine PRB 3310 A3630-1500kv (Old Miss GEICO), which, A3630-1800KV DYNM 3830. com The Same settings
May be the propeller size, use 45 mm, 5s battery
Manny

[J.W. Pepper]

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!

Darin,
THANK YOU SO MUCH for starting this thread, now I can tell all the "wanna be experts" on this forum "see I told you so". I'm referering to this sentence in your post... The one weakpoint I would say is the wire size on the motors themselves. This seems a weak-point in the system,...

There's not one, but two threads in which all the "OSE experts" claim that IM-31's require 5.5mm bullets or I'm going to "burn 'n' learn". Where are all those "experts" now??

In this thread... http://forums.offshoreelectrics.com/...5mm-connectors - post #8 (towards the bottom) I clearly stated the exact same thing as you did... Install 5.5mm bullets and the motor wires themselves become the weak link - please note: I'm talking about the V1 IM-31's.

I did several posts in that thread and the 1st one (same subject) attempting to get people to see the flaws in their thinking, all to no avail, I finally said to myself... don't bother, they're minds are made up, they don't want to be confused with facts.

Now I get say... go argue with the designer of the boat - Darin Jordan & all the graphs / charts he posted in this thread, now Mc-Fly, do you finally get it??

The good thing about those threads / posts is it forced me to do my own research. One of the things I learned is: there's 2 different type's of 4mm bullets, cheapo's & high current / high efficiency like those made by Castle Creations. The Castle's are a one piece design like the 5.5mm & 6.5mm bullets, AND, they're made in China, NOT America as one poster claimed - see attached for proof.

Keep up the good work...

Signed: One very proud & happy owner of a Proboat IM-31 V1

[Darin Jordan]

Whoa, Whoa, Whoa... I am the FIRST one to tell people that they should replace with a minimum of 5.5mm contacts.

The tests I mention above are with a stock prop. No prep, slipping like a mother, not loading the system at all.

If I was going to change that and put ANYTHING bigger on, I'd be the very first to swap contacts. I don't have ANY boats that run anything smaller than 5.5's on the motor leads. You'd never survive a real race without them.

All that said, whatever works for you, Man... :) It's all good if you are having reliable fun. That's the goal!!

Take care,

[capnswanny]

Thanks

[tlandauer]

@J.W.Pepper,
I really don't want to get into this debate, but I can't help but wonder why you need to further cut your motor wire in order to solder the 5.5mm connectors?
Like you, I used 4mm until I started to convert to 5.5 mm, as I get better with soldering ( I read that you are good at it, so should be a piece of cake) , I just de-solder the stock 4mm and re tin the leads and stick it into the "bucket" of the 5.5mm connector, you need to really pre-tin them well, I also put some solder in the 'bucket", then I place the end of the tinned wire into the bucket and heat it up thru the little hole until the solder melts, ( I need to say the now Steve @OSE also carries the cut style 5.5mm connectors, it might be easier to solder, depending one's personal preferences) by now the wire can be pushed in all the way, make sure it is still in liquid form, hold wire still and wait for the solder to cool off. Never have to fold the wire for it to fit in the bucket. The finished look is as if the wire is ENCASED in the bucket. ( Chicago mobsters encasing victim's legs with cement in buckets comes to mind) You are fine, just undo the 4mm and use the same exposed wire for the 5.5mm. don't cut any further.
Just because the bullet connectors have a larger diameter than the motor wires does not necessarily mean the motor wires are already the weak link. In fact all my motor connectors have a larger diameter than the motor wire, but the temp is COOLER after a run with readings from the temp gun to verify.
Again, I can understand your ambivalence and I am not questioning your train of thoughts, just want to tell you that I do not FOLD the wires to fit the larger connectors.
After seeing your 12.7 cal. cartridge, I refrain from liberally using the word "bullets",
Happy boating!

[tlandauer]

Darin,
My sincere apologies to you for going off topic, I thought this was another "do I Need 5.5mm Connectors?" thread, since my typing is slow, I didn't delete it, may be the moderator would.
I move that we respect Darin's thread and any further thoughts on the 5.5mm issue be posted on a separate thread.

[J.W. Pepper]

@J.W.Pepper,
I really don't want to get into this debate, but I can't help but wonder why you need to further cut your motor wire in order to solder the 5.5mm connectors?
Like you, I used 4mm until I started to convert to 5.5 mm, as I get better with soldering ( I read that you are good at it, so should be a piece of cake) , I just de-solder the stock 4mm and re tin the leads and stick it into the "bucket" of the 5.5mm connector, you need to really pre-tin them well, I also put some solder in the 'bucket", then I place the end of the tinned wire into the bucket and heat it up thru the little hole until the solder melts, ( I need to say the now Steve @OSE also carries the cut style 5.5mm connectors, it might be easier to solder, depending one's personal preferences) by now the wire can be pushed in all the way, make sure it is still in liquid form, hold wire still and wait for the solder to cool off. Never have to fold the wire for it to fit in the bucket. The finished look is as if the wire is ENCASED in the bucket. ( Chicago mobsters encasing victim's legs with cement in buckets comes to mind) You are fine, just undo the 4mm and use the same exposed wire for the 5.5mm. don't cut any further.
Just because the bullet connectors have a larger diameter than the motor wires does not necessarily mean the motor wires are already the weak link. In fact all my motor connectors have a larger diameter than the motor wire, but the temp is COOLER after a run with readings from the temp gun to verify.
Again, I can understand your ambivalence and I am not questioning your train of thoughts, just want to tell you that I do not FOLD the wires to fit the larger connectors.
After seeing your 12.7 cal. cartridge, I refrain from liberally using the word "bullets",
Happy boating!

I deleted the post, happy??

Had your read it from top to bottom instead of the other way around you would have noticed that...

I asked about substitute props since Darin stated that he S&B'ed the stock prop and tried other props as well. I don't know how to S&B props and have no interest in learning. And not that it really matters, but the unbalanced, unprepped stock prop weighs .30ozs. Jan's CNC'ed aluminum props weigh .10ozs, they're balanced and ready to go, with some minor prep & sharpening there even better. BTW: those are actual weighs obtained at the local post office.

Regarding soldering bullets... Your right I do have a lot of soldering experience. We all pick up/learn skills from our dads, for me soldering was one of those skills. I've also done it professionally. I did have problems with the first several bullets I did, then I got smart and constructed a jig to hold them still, add some practice, no more probs.

But I have never been able to de-solder bullets. I have 2 soldering irons, Weller soldering station and a Radio Shack cheapo high wattage iron. The Weller is perfect for most jobs including new bullets, but it doesn't put out enough heat to un/de-solder bullets. I have also tried the RS iron, hold it on the bullet till hell freeze's over and solder just will not liquify, so how the heck are you doing it??

Now you know why I expressed concern about shortening the motor wires, to date, the only way I have been able to remove bullets is to cut them off. That is why I want to put the 5.5's on the SK120A, if I upgrade the motor I'll put 5.5's on the new one. In the meantime, I need to figure out how to remove the 4mm's I put on the stock motor so I can replace them with 5.5's.
I know this is not a how-to thread for bullets, but I would appreciate you telling me how your un/de-soldering them.

I could have swore Darin said something regarding the boat handling well if properly prepped, I asked him to eleborate; specifically replacing the stock trim tabs with the speedmaster adjustable ones Steve sells for the IM-31's - look in his store. I've scanned through his post and can't find that part, only thing I found is that he used different turn fins but he didn't say which one's.

Right now, I'm tired, frustrated, and burned out on the whole FE thing - wish I would have never bought that dam boat. But I'm into it too deep, so I either sell it at a serious loss, or make it work. I hate losing money, so looks like it's the latter.

Off topic, do yourself a favor and get one of Jan's CNC'ed x442's for your Rio. Goto Steve's how-to section for making prop adapters. Then AQ's website, find the prop prep instructions, put the satin finish on it like GR says too, sharpen it and go enjoy the improved performance you'll experience.

[Heaving Earth]

I have a torch for desoldering. Takes about 3 seconds and it falls off

[tlandauer]

I deleted the post, happy??

It was MY BAD, I came home after work so late and had NO business to post anything without thinking twice, I just wanted to make sure my post here would not draw the whole discussion into another totally different topic. Thank you for your kind understanding. Thanks for the suggestions for the props !

[Darin Jordan]

I could have swore Darin said something regarding the boat handling well if properly prepped, I asked him to eleborate; specifically replacing the stock trim tabs with the speedmaster adjustable ones Steve sells for the IM-31's - look in his store. I've scanned through his post and can't find that part, only thing I found is that he used different turn fins but he didn't say which one's.

I haven't replaced my trim tabs on my P-Ltd level IM31's... but I have mentioned that the bolt-hole pattern on the stock ones is conspicuously the same as the Speedmaters you mention... Must be a coincidence...

Stay tuned on the turn fins... I'll have something to report on that here shortly.

I'm not sure what you guys are looking for in ways of speed from the factory power system, but in testing, one of the best all around handling/performance props I've found has been the reliable and ever present ABC 42x55. If you prep it well, and maybe add just a tick of pitch out at the tips, it's a 40+mph prop on the IM31 with quality batteries and no other changes...

[J.W. Pepper]

I haven't replaced my trim tabs on my P-Ltd level IM31's... but I have mentioned that the bolt-hole pattern on the stock ones is conspicuously the same as the Speedmaters you mention... Must be a coincidence...

Stay tuned on the turn fins... I'll have something to report on that here shortly.

I'm not sure what you guys are looking for in ways of speed from the factory power system, but in testing, one of the best all around handling/performance props I've found has been the reliable and ever present ABC 42x55. If you prep it well, and maybe add just a tick of pitch out at the tips, it's a 40+mph prop on the IM31 with quality batteries and no other changes...

Before I continue... There's too much valuable info in this thread to have it closed. So, I deleted my post (it was 8, 9 or 10) because it contained controversial material. I feared the smart a$$'es would have ran with it leading to the possible closure of this thread. Think of it as my public service to the OSE community.

Darin,
It was my intention to use the SM aluminum adjusters with the stock TT's because they would provide for precision adjustments. Manual says to grab a big set pliers (see attached) and bend them. BTW: everybody but Steve sells those SpeedMasters in sets of 4, think there intended for larger boats where they would be used in pairs on each side of the transom.

Stay tuned on the turn fins... I'll have something to report on that here shortly... Thank you for the update, I'll stay posted.

Is the ABC 42x55 prop the same as a Grim Racer 42x55 (AQUB9725) prop??

Thank you for your continued interest and willingness to help those of us with IM's.