P Spec Tunnel Data

[SeanKewley]

I'm not interested in the shunt discussion at all... Just wondering what others are seeing with their P-Ltd tunnel heat racing setups (Subject of the thread).

 

[hugh hargett]

Got ya. Wasnt trying to be funny there was a side conversation about accuracy of the charts data.

 

[hugh hargett]

D, Jay is right it looks at the pack voltage then through math in the algorithm it calculates voltage looking at the registers in the mcu. Its most accurate in the mid amperage ranges . It falls of slightly at the high and low (below 20 amps) end. My suggestion? By mine - when its finished. it will measure true current. The eagle tree is better at giving a true amperage reading as its directly measuring current.

the info is straight from the engineer at castle.

the castle uses standard old back emf capture for all it reading but the rpm and voltage readings are fairly accurate.

Im kinda glad to hear it coz mine will be so much better.

For what were doing here though its fine.

 

[hugh hargett]

heres a shot of the Graph from the V2. caslte ice hv

 

[D. Newland]

I have no idea about the accuracy of the ICE data logger. ...In any case there has been a lot of argument with no data to back it up. Many of you have the equipment to see what's happening. What do you see with your boats?

Lohring Miller

I don't know if it's actually an argument. I think it's more of a, "stop posting that UL-1 motors are OK @ 100 amps", especially if you have no idea regarding the accuracy of your equipment. Every time you post it (and it's been many), I literally ask myself why you think it is helpful information as it relates to the advancement of FE. Most of the times, you're called out on it, but yet you keep posting it. So, you must see some public benefit regarding your information. I don't, but that's just me. I also don't feel it's responsible, knowing your involvment in FE racing and status in NAMBA as a racer and Safety Director, to be posting such information, knowing these motors will hit the wall faster than more expensive motors.

I've never data logged, unless you count my pen/paper method as data logging. I suppose it is. I also don't trust my on-board MPG computer on my truck. I do things by hand. What I know (and feel) is by hand-calculating the average amp draw and by knowing my runtime, mAh drain and motor tempurature. It falls in line with what Joerg said on RRR the other day. It's also what I feel is a responsible public message for the UL-1 motors.

"The UL1 motor works best in a range of 50-75A, max. efficiency is at about 88% at 60A. In the 50-75A range the power loss is 100-120W - an amount that can be cooled without a big problem. At 100A the losses reach 200W and at 125A its even 300W - an amount you might just barely be able to cool. At 150A and 400W its gone, especially as in reality the losses are even a bit higher, because the IR increases with temperature. This makes it completely clear, that you are running this motor on the very sharp edge of thermal death."

My on-board MPG calculator on my truck is consistently .5 to .6 mpg's too generous. Maybe your equipment is is a little off, too.

Hugh-thanks for your comments/recommendations about logging equipment. I find comfort in the way I'm doing it. But, with that said, I do have a new Castle ESC coming to me with that function. I won a very nice coupon from Castle at a recent raffle. Still won't give up the pen/paper, though.

 

[hugh hargett]

"Hugh-thanks for your comments/recommendations about logging equipment. I find comfort in the way I'm doing it. But, with that said, I do have a new Castle ESC coming to me with that function. I won a very nice coupon from Castle at a recent raffle. Still won't give up the pen/paper, though. "

And dont you ever give up your pen and paper I wont either. I suggested always comparing to theoretical numbers for a better picture. You may find out useful things doing it that way like finding the slip etc. then you can put that info in a book to remember for different setups.

I like lohring posting his data i think it is helpful to see what other are getting back with limited setups. You cant just take his numbers and go set you boat based on that but it is posittive feedback and it ususally starts a good technical talk.

what D. N. just left is great knowledge we wouldnt have gotten without Lohrings Post. lohrings my pal yall cut him a little slack.

Let me say one thing on motors and heat;tried to say it on the other thread.

A motor likesto be around 160 degrees optimum if it below that you can pust it harder if its above that you satrt to lose as the magnets get hot. This applies to most of the motor we use not just the AQs

 

[lohring]

My old style Eagle Tree loggers use Hall effect current sensors, not shunts. I've been data logging boats for a long lime. It's useful when you are exploring areas where there isn't a lot of information.

I never said UL-1 motors should be run at 120 amps. I said that people who win races in my area ARE running them at these currents or higher. I've also seen the data log from a JAE P limited rigger (not mine) where the current spikes reached 150 amps. That did turn out to be a little too much. It's the result of the rules that limit equipment. That guarantees that the limited equipment will be pushed to the edge of failure. If you read the rules discussion at http://www.rumrunnerracing.com/feforums/showthread.php?t=32256 you will see that I agree that the UL-1 motor is most efficient at its rated current around half the current we actually run. You will also see what I believe the consequences of the various rule elements are. An understanding of what's actually happening and the consequences of different rule systems might help the next time new rules are proposed.

By the way, I think the "spec" rule system with possible additions works very well at getting new racers into electrics. Spec propellers worked very well in my club in beginner's stock classes. The 1/10 scale rules that inadvertently limit propellers as well as equipment also works very well where people want to concentrate on boat building and not power plants. Today, low cost equipment can easily handle 100 amps. There are many ways to write rules that use this. Limiting voltage and current would be a direct way to do this. See the FAI pylon rules.

Lohring Miller

 

[Peter Gise]

Or limit the ESC to the stock AQ/UL-1? Might level the playing field a bit more and save some $$$.

JMHO,

Pete

 

[lohring]

Or limit the ESC to the stock AQ/UL-1? Might level the playing field a bit more and save some $$$.

JMHO,

Pete

I think that's the way the rules should have been written. It wouldn't save any money because the Turnigy Marine 120 low cost speed control works very well. Maybe the high Kv motors shouldn't have been included either. However, with restricted motors and ESCs we would be pushing both the motor and speed control.

Last Sunday's P limited rigger racing at my club had 4 Raptor riggers, all but mine running essentially the same props. The speeds were directly related to equipment internal resistance. The fastest boat (not mine) ran an ICE 200 ESC, 6.5 mm connectors, and Grim Racer packs. The slowest boat ran a new UL-1 controller and inexpensive batteries. It may have run Deans connectors. Setup was also a factor, but probably a minor one in this case.

Lohring Miller

 

[Darin Jordan]

Or limit the ESC to the stock AQ/UL-1? Might level the playing field a bit more and save some $$$.

JMHO,

Pete

I think that's the way the rules should have been written. It wouldn't save any money because the Turnigy Marine 120 low cost speed control works very well. Maybe the high Kv motors shouldn't have been included either. However, with restricted motors and ESCs we would be pushing both the motor and speed control.

Last Sunday's P limited rigger racing at my club had 4 Raptor riggers, all but mine running essentially the same props. The speeds were directly related to equipment internal resistance. The fastest boat (not mine) ran an ICE 200 ESC, 6.5 mm connectors, and Grim Racer packs. The slowest boat ran a new UL-1 controller and inexpensive batteries. It may have run Deans connectors. Setup was also a factor, but probably a minor one in this case.

Lohring Miller

I'll say it again... I don't think it's fair to the "Other" manufacturer involved if you were to limit this to just ONE brand of ESC... The class is setup around the idea of running "current and past" power systems from "popular RTR offerings" (that's from the rulebook), and targeting just one or the other would be a deal breaker for some of us... Would also be silly... in my opinion.

The original proposal drafts of the rules, early on, (I know... I wrote them...) specified the use of the "stock" ESCs... though you were allowed to mix-match as you saw fit. Would have just changed the failure point, however... and they aren't "cheaper" than many aftermarket options... I would have supported this option though... would have simplified the class quite a bit... and, perhaps more importantly, removed the perception of some kind of advantage with aftermarket ESC, which may, or may not exist.

 

[raptor347]

Last Sunday's P limited rigger racing at my club had 4 Raptor riggers, all but mine running essentially the same props. The speeds were directly related to equipment internal resistance. The fastest boat (not mine) ran an ICE 200 ESC, 6.5 mm connectors, and Grim Racer packs. The slowest boat ran a new UL-1 controller and inexpensive batteries. It may have run Deans connectors. Setup was also a factor, but probably a minor one in this case.

Lohring Miller

I didn't have the Ice 200 in the boat last weekend. It was only a water proofed/cooled ICE 100. It did have the 6.5's and GrimRacer batteries though.

I did like the new prop option, I have more work to do.

The speed differences aren't due entirely to the difference in watts used.

 

[Bill Oxidean]

What prop are you guys running?

 

[ron upton]

m445 on my ps295

 

[chuckg]

Or limit the ESC to the stock AQ/UL-1? Might level the playing field a bit more and save some $$$.

JMHO,

Pete

I think that's the way the rules should have been written. It wouldn't save any money because the Turnigy Marine 120 low cost speed control works very well. Maybe the high Kv motors shouldn't have been included either. However, with restricted motors and ESCs we would be pushing both the motor and speed control.

Last Sunday's P limited rigger racing at my club had 4 Raptor riggers, all but mine running essentially the same props. The speeds were directly related to equipment internal resistance. The fastest boat (not mine) ran an ICE 200 ESC, 6.5 mm connectors, and Grim Racer packs. The slowest boat ran a new UL-1 controller and inexpensive batteries. It may have run Deans connectors. Setup was also a factor, but probably a minor one in this case.

Lohring Miller

I'll say it again... I don't think it's fair to the "Other" manufacturer involved if you were to limit this to just ONE brand of ESC... The class is setup around the idea of running "current and past" power systems from "popular RTR offerings" (that's from the rulebook), and targeting just one or the other would be a deal breaker for some of us... Would also be silly... in my opinion.

The original proposal drafts of the rules, early on, (I know... I wrote them...) specified the use of the "stock" ESCs... though you were allowed to mix-match as you saw fit. Would have just changed the failure point, however... and they aren't "cheaper" than many aftermarket options... I would have supported this option though... would have simplified the class quite a bit... and, perhaps more importantly, removed the perception of some kind of advantage with aftermarket ESC, which may, or may not exist.

In IMPBA D12 they require spec controlers and I asked if it could be changed to any 60 amp controler as this seems more logical and cost effective. Not this year ... maybe next year.

 

[hugh hargett]

As an electronic guy I dont see why the esc matters if you limit the mah and c rating on the batt. No matter what esc they run it will fry when they push past the limits of the power supply. Point blank the esc with the lowest resitance wiill deliver more volts to the motor period. This long ass debate is futile. Unless IMPBA has a problem with people in p spec getting all there LEGAL battery voltage their shouldnt be any issue with whatever esc you run- its silly. End of story. All the rule does is promote AQ equipment . I have no problem with AQ equipment but nothings fair when one has a 20 dollar lipo and the other has a 140 dollar lipo the real difference is in the IR off the components. Come on fellas this aint hard if they got and approved motor and batteries within rules catered to keep it fair. Let em race.

First thing that needs to happen is whomever writes the rules need s to have a general background in electronics and understand whats going on. Its clear some of us dont buy the points brought up in debate.

Jus my .02

 

[lohring]

The P spec hydros have mostly been running S-15 props, The P spec tunnels usually run 42 x 55 props. These both seem to be close to the maximum for the UL-1 motors, but experimentation goes on. Hydro speeds have increased over 5 mph in the last two years, all due to prop selection.

Lohring Miller

 

[lohring]

Is an electronic guy I dont see why the esc matters if you limit the mah and c rating on the batt. NBo matter what esc they run it will fry when they push past the limits of the power supply. Point blank the esc with the lowest resitance wiill deliver more volts to the motor period. This long ass debate is futile. Unless IMPBA has a problem with people in p spec getting all there LEGAL battery voltage their shouldnt be any issue with whatever esc you its silly. End of story. All the rule does is promote AQ equipment . I have no problem with AQ equipment but nothings fair when one has a 20 dollar lipo and the other has a 140 dollar lipo the real difference is in the IR off the components. Come on fellas this aint hard

Even the low cost 5000 mah batteries are easily capable of supplying 200 amps. 2S packs could supply 400 amps. That's way more than any of the spec motors and speed controls can handle. The limiting factors today are the motors and ESCs. The rules encourage pushing the least capible piece of equipment to its limit. This will be well beyond its point of best efficiency. As I stated above, using low resistance equipment in front of the motor makes boats faster. You don't have to spend a lot of money to do this, but it isn't the lowest cost solution.

Lohring Miller

 

[Darin Jordan]

The P spec hydros have mostly been running S-15 props, The P spec tunnels usually run 42 x 55 props. These both seem to be close to the maximum for the UL-1 motors, but experimentation goes on. Hydro speeds have increased over 5 mph in the last two years, all due to prop selection.

Lohring Miller

Just as a data point, Lohring... I ran my P-Ltd Lynx tunnel this weekend for the first time.... After some tuning and tweaking to get it handling correctly, I was VERY competitive, and the data shows that I pulled an average of 86amps, with a "Max" of 113A, and a maximum ESC temp of 123-degrees... motor was cold. Prop was an ABC 42x55, detounged and slightly back-cut, but otherwise stock...

 

[hugh hargett]

Is an electronic guy I dont see why the esc matters if you limit the mah and c rating on the batt. NBo matter what esc they run it will fry when they push past the limits of the power supply. Point blank the esc with the lowest resitance wiill deliver more volts to the motor period. This long ass debate is futile. Unless IMPBA has a problem with people in p spec getting all there LEGAL battery voltage their shouldnt be any issue with whatever esc you its silly. End of story. All the rule does is promote AQ equipment . I have no problem with AQ equipment but nothings fair when one has a 20 dollar lipo and the other has a 140 dollar lipo the real difference is in the IR off the components. Come on fellas this aint hard

Even the low cost 5000 mah batteries are easily capable of supplying 200 amps. 2S packs could supply 400 amps. That's way more than any of the spec motors and speed controls can handle. The limiting factors today are the motors and ESCs. The rules encourage pushing the least capible piece of equipment to its limit. This will be well beyond its point of best efficiency. As I stated above, using low resistance equipment in front of the motor makes boats faster. You don't have to spend a lot of money to do this, but it isn't the lowest cost solution.

Lohring Miller

I disagree the rules dont encourage pushing equipment to its limits the racers do. After looking at it it appears the rules are simply trying to create a drivers class ; where the equipment is for the most part identical. You have a little flexibility that some havent explored. Has anyone actually looked at all the motors that come in the commercially available rtr boats? For instance wouldnt a traxxas spartan motor qualify? Yes I think it would have to be allowed by the stated spec rules.

It seems to me that is the racers that have gravaitated to the aq's as they make a few rtr boats. Whats overseas? whats in all the rtr stuff thats sold on hobby king? I dont know. Do any one of you? By the rules unless Im reading wrong it would all be legal powerplants there. If its limited to us Manufac. thats not so INTERNATIONAL is it My IMPBA mates? As far as the esc's I guess youre missing my point. Its limited racing - it was never intended to have "OPEN" performance. It is the experienced racers like Darin for example that has learned how to get the most out of his setup and it is the novice that try to copy and burned up his equipment. The racers push the equipment not the rules. Want reliability? detune. Want real performance? go open.

Lohring your talking of getting the most out. Im speaking in terms of making the power in the class identical.

its not about the battery price its about the lower IR the lower IR setup requires less amps to produce the same power but its fair based on the voltage limits rule period. IMPBA cant get around ohms law.

As I stated long ago spec classes, because of the experts present, are the last classes id enter as a beginner. All you will do is burn something up trying to hang.

My point