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Thread: P Limited Tuning Tips by David Newland

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    Default P Limited Tuning Tips by David Newland

    There’s been a divide between NAMBA racers as of late, concerning opinions over the quality of the P-Ltd motors. As part of my effort to help, I’d like to share my philosophy and what I do with P-Ltd Setups. If you find yourself unsatisfied with this class, burning up motors, etc, there are some things you can do to help your situation, or at least create an acceptable level of failure. If anyone has a question, please let me know. Ask here or send me a PM.
    I’ve mentioned in a few posts about racing mentality. This is a big part of my success with P-ltd classes. You need to ask yourself if you’re willing, able and have the desire to setup, tune and race differently. If not, maybe P-Ltd isn’t for you.
    You may actually find the end result of my process boring, and that’s OK. We racers come in a lot of different shapes and sizes. And, NAMBA has other Power Parameters that may fit your needs. Just know that my goal here is to help keep P-Ltd viable. At this point in time, it is my opinion that we do not need a “better” motor on the list. If that happens, it will just be a matter of time when that motor if flogged into a crispy mess, too.

    1) Motor Temperature. We all know that P-Ltd motors are temperature sensitive. We know that they will be happy at a certain temperature, then go nuclear at a slightly higher temperature. However, some racers fail in how they check the temperature, have an incorrect temperature threshold, or just say, “Well, it didn’t burn up that heat, I’ll keep running it. That white smoke really didn’t smell like anything too serious”.

    I don’t data log. I’m not against it, but I just don’t. I feel checking motor temperature is more important and I’m comfortable with my ability to test a motors temperature and set a realistic threshold. And, with the different production runs, motor quality is going to vary from time to time. Therefore, the “envelope” is going to shift. Don’t be on the edge of the envelope or you will burn motors. You do not allow yourself any room for mistake or different motor variance.

    125 degrees. That’s my comfort level with regards to end bell motor temperature. And, I test that during open water when I’m the only boat on the water. That way, when I’m racing, the boat will run looser due to other boats on the water making wakes, etc. I verify this after a race, too.

    I know what 125 degrees feels like on my finger. I also verify and somewhat calibrate/validate my feel with a temp gun. If you don’t have one, get one. You should, at a minimum, be laying a finger across the end bell after every P-Ltd run you make. Use the temp gun on occasion, too.

    2) Testing a new boat/motor/setup. Standard rules apply here, but with even more emphasis on runtime and prop selection. With regards to prop selection for the first time, you need to start with something familiar, or something that you know will work, or something your partner knows will work. It must be a conservative prop selection. Start small and work your way up.
    If you run 1 lap with the boat and the setup isn’t right, bring it right back to shore. Don’t run it more because it’s not going to get better. Immediately. Back to shore. Get the trim figured out and run it again. If it’s not right, immediately back to shore. Keep checking the motor during this time, too. Don’t say, “I just don’t want to un-tape it AGAIN!” Do it. Un-tape it and check.
    Once you get it trimmed and the motor was giving no obvious signs of stress during your quick runs, recharge and run the boat for 60 seconds. That’s it. And pin the throttle. If you have to let up during this 60 second run, your setup isn’t right. It’s too loose or your turn fins aren’t set right. If it’s too fast to WOT for 60 seconds, prop down. Recharge, make a setup change, and run it again.
    Once you nail down a WOT 60 second run, test the motor heat. If you want more info, recharge your pack. If you ran for 1 minute exactly, your pack recharge will tell you an average amp draw. 1000 mAh put back into the packs = 60 amps on average. 1200 mAh = 72 amp average. 1300 mAh = 78 amp average. That’s about as high as I’ll go. Maybe 80 amps, but it starts to be a game of Russian Roulette with the motor.
    Now, remember, you’ve done your homework to select a safe prop to start testing. If the motor is ambient, move up a prop. It shouldn’t be, but if your motor is hotter than 125 degrees, prop down. Or, start eliminating drag (loosen the boat up, use a shorter rudder, smaller turn/skid fins, going from aluminum to stainless turn/skid fins, etc).
    Rinse and repeat. Take notes. Keep a spreadsheet of your known setups, hull type, prop, ESC, cells.

    3) Speed. I couldn’t tell you how fast any of my P-Ltd boat are running. I’ve never GPS’d a boat. Speed is not important to me. Chasing MPH is not important to me. With rare exception, anyone who posts a MPH is either wrong on the number, or wrong for testing the way they do.
    Yes, I’m talking about you. Stop posting how fast your boats are. Wait, do it so I can get a chuckle.

    We also have to make 12 turns during a typical sprint heat (which many racers greatly miss the target tuning here, me included), so SAW speed is barely relevant. I also feel it’s a mentality that some racers have that tend to have problems. Burn motors, for instance. Maybe they are chasing MPH, maybe they want to be faster than the next guy. Than all of the guys. Maybe they want a P-Ltd boat that can pass on the outside. I don’t recommend that mentality.

    I have calculated the statistics. You have a better chance at winning the class by NOT having the fastest boat. This is counter-intuitive, I know. Slow down. You’ll do better. And save money.

    4) Known setup. Once you’ve tested your boat and are comfortable with its handling and ability to get around the course and the motor temperature is good, resist the urge to continually tinker with it. Now, I know we are racers and we like to tinker/improve, but I will say that my P-Ltd setups get locked in and I rarely make changes. If I do, I do it very carefully. Minor changes then I tell myself I need to leave it alone. I will clean up props, sharpen things here and there, but I just won’t keep trying different props to chase MPH. After all, I don’t even know how fast my boats are going, anyway.
    99% of the time, I never add more prop to a boat mid-race. Even during club racing. Good things rarely come from it. If you find yourself wanting to make a prop change mid-race, resist the urge. Remember, you don’t have to be the fastest boat on the course. Finish out the day and wait for your next test/tune session.

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    5) Racing mentality. In a typical 4 round race, you need to complete 24 laps with your boat. You don’t need to race to the first turn and you don’t need to get past every boat in front of you on the first lap. Run your race the best you can with your setup. If you get beat, don’t go to the prop box and throw on a bigger wheel. Work on racing more efficiently. Get a better start, run tighter lines. Focus on shaving your heat time. Find joy in handing other racers rope for which to hang themselves.
    Have finesse.

    6) Racing Setups. All of my P-Ltd boats can run a race, with 5 other boats, at full throttle 95% of the time AND finish. If your boat can’t do this, you need to go back and work on your setup. Some boats are too loose, over-propped or some racers like to purposely over-prop their boats and just run them at 80% throttle until they need a little extra umph. Trust me, this doesn’t work. You should shoot for a boat that runs like a Cadillac out there. Smooth and consistent. Your driving is extremely important in winning and it’s something for which a bigger prop can’t compensate.

    7) Clean Driving. It all starts with a clean and well positioned boat at the start. Practice, practice, practice. Enter and exit turn 1 in the same lane. Continue to race as tight as you comfortably can, without making any errors. Not cut buoys, not jump starts. Ever. If you do, tell yourself not to do it again. WOT with a boat that is set up to handle it. Pay attention to your heat times. Log them if necessary. Set reasonable goals. If your P-Ltd mono runs a 1:50 consistently, work on your driving and setup to get it to 1:45 the next time out. And don’t get their by propping up. If you are out of ideas, ask around.

    8) Boat to boat differences. This comes up more than it should. “My buddy has the exact same boat and prop as I do, and I keep burning motors!” It just doesn’t work that way. Each boat/setup is different, no matter how much alike you think they are. Each boat needs to be tuned on its own merits. Period. Maybe during the tuning process you’ll stumble on the reason for this phenomena, but I doubt it. It’s a mystery.

    9) Hardware. .150 cables. That’s all I use for P-Ltd. Octura small 5 mm to .150 collets. The Aeromarine’s are too heavy. .187 cables are too heavy. Polish the stub shafts. My monos have the motors aft for short cable runs. Focus on rudder length. Use Speedmaster hardware and have 3-4 different style/length of rudders to test with. Go in with a friend if you don’t have the money to do this yourself, or just keep cutting on your rudder until you cut too much to get your boat around the course well, then buy another and cut it appropriately. Sharp hardware. Like, cut your finger sharp. Props, too. How many times have you heard this, but I doubt most actually have (what I consider) sharp props. Buy a handheld diamond knife sharpener. Don’t forget about the rudder. Any nicks/dings? Fix them. Re-sharpen. I use 8 mm connectors from motor to ESC, and 5.5’s from cells to ESC. On occasion, I also use 5 v micro fans that plug into my Rx. I make a mount for them, Velcro to the hull and have them blow on the end bell. Not all of my boats have this, but some do. However, I do this to not prop up, just to make sure my setups are keeping my motor actually lower than 125 degrees. I like ROI (return on investment). I want my equipment to last.

    10) Ask for help. Find a racer that knows what he’s doing. Bend their ear. Get feedback. Find what makes sense to you and consider implementing it (carefully) into your racing program. You may need to talk to a few to get a sense for who has a racing program that makes sense to you. Share your results. They will take even more interest in your setups and continue to provide input, knowing that you not only are listening to them, you’re actually implementing their recommendations.

    11) Consistency. Once you have a setup that can win races, or otherwise runs very respectively among your club members, leave it alone! Resist the urge to tinker, again. Put a bag on it and call it a day. Start building another boat if you have to do something to keep your interests up. If you do tinker, it should be ever so slight, but know you’ll enter the Russian roulette motor burn game. My P-Ltd Mono has been unchanged for 4 years. Rigger 5 years. I went 3 years with my Sport Hydro before building another one. I don’t have a problem bagging my boats and leaving them alone for quite a long time.

    12) Understand we are dealing with Chinese motors that have different production runs. It will bite you at some point, as we all have been bitten. However, P-Ltd is worth a lost motor or two in a year for me. Any more than that, then I need to go through this list again, word for word. Don’t push the envelope. Find a nice, comfortable place well within the envelope and work on other aspects of your racing program (setup/driving) to find success heat after heat.

    13) Motor Maintenance. I frequently spray out the motor completely with WD 40 and especially the bearings, then re-oil. I use a Tri Flow Teflon oil found at bike shops. OPC runs have to have this done at the end of every race day or tune day. Closely inspect the wires at the end bell. If you see them start to melt together, consider that a sign that you’re running them too hard. Cut off the band, cut off the individual wire shrink, and replace with shrink just as it was OEM. Go back and tune your setup better.

    14) If something goes wrong, analyze it. Why do you think it happened? What do others say? And, most importantly, what do you need to do to make sure it doesn’t happen again?

    15) Be prepared to run slower. Sounds counter-intuitive in the world of Fast Electrics, but you may just need to prop down. I seriously doubt it will affect your race standings at the end of the day. After all, the fastest boat wins the class 33% of the time. You’re odds are better at winning if you tune your boat to not be the fastest in the class. Boring, I know, but it works.

  3. #3
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    Nicely stated, David. Very nicely stated.

    Thank you!
    Darin E. Jordan - Renton, WA
    "Self-proclaimed skill-less leader in the hobby."

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    Nice!!
    Jesus is King .......NAMBA20...Caterpillar UL-1, P-Spec OM29, P-Mono DF33, P-Spec JAE, Aussie 33" Hydro-LSH, Sprintcat CC2028 on 8s, PT SS45 Q Hydro, PS295 UL-1 power, OSE Brothers Outlaw QMono 4-sale, Rio 51z CC2028 on 8s

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    Thanks Dave. I just need pond time and I'll clean all of your clocks, lol...

    I've also never used a GPS or data logging. I can see if my boat is running well or not so well. After running boats for so long sometimes it's all feel and sight, experience... I just time my laps and try to make them shorter by driving better and adjustments but, gosh I hate to stop, un-tape and re-tape. One day I'll have a system for hatches that seals them with little or no need for tape.
    Nortavlag Bulc

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    David,
    Nice job no BS I think anyone new to boating could put to good use before they go out and buy/burn down everything. ROI most don't even think about it because it is a Hobby but so vital to keeping RC Boating fun for years. I have been RC boating since 1972 and have loved it. Again needs to be a newbie must read. I hope you will not mind if I borrow it to send to new people and will give you credit.
    Mike
    Do It Like You Mean It .....or Don't Bother

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    Man How did miss this thread.... Nicely done. A must read for everyone. Run slower to win?? The second place Gas Mono at Fall Nats last month was running a stock motor. If we spent half as much time working on our driving and a solid set up as we do trying to get that extra mile per hour out of out boats, we would be soooo much better off... Not only at the podium but to avoid our boats being floating targets for the other racers.

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    Quote Originally Posted by Chilli View Post
    Man How did miss this thread.... Nicely done. A must read for everyone. Run slower to win?? The second place Gas Mono at Fall Nats last month was running a stock motor. If we spent half as much time working on our driving and a solid set up as we do trying to get that extra mile per hour out of out boats, we would be soooo much better off... Not only at the podium but to avoid our boats being floating targets for the other racers.
    I took out my cooked AQ2030 motor from my JAE and dropped in a PB1500.. I knew it would be slower but I focused on my driving and took first in D20 at our finals this year..
    Jesus is King .......NAMBA20...Caterpillar UL-1, P-Spec OM29, P-Mono DF33, P-Spec JAE, Aussie 33" Hydro-LSH, Sprintcat CC2028 on 8s, PT SS45 Q Hydro, PS295 UL-1 power, OSE Brothers Outlaw QMono 4-sale, Rio 51z CC2028 on 8s

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    Quote Originally Posted by Brushless55 View Post
    I took out my cooked AQ2030 motor from my JAE and dropped in a PB1500.. I knew it would be slower but I focused on my driving and took first in D20 at our finals this year..
    Probably also found better corner and corner exit speeds in the process... :)
    Darin E. Jordan - Renton, WA
    "Self-proclaimed skill-less leader in the hobby."

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    Quote Originally Posted by Darin Jordan View Post
    Probably also found better corner and corner exit speeds in the process... :)

    My driving skills kinda suck, so I really could not answer that 100% but I will say it felt like a better machine
    Jesus is King .......NAMBA20...Caterpillar UL-1, P-Spec OM29, P-Mono DF33, P-Spec JAE, Aussie 33" Hydro-LSH, Sprintcat CC2028 on 8s, PT SS45 Q Hydro, PS295 UL-1 power, OSE Brothers Outlaw QMono 4-sale, Rio 51z CC2028 on 8s

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    This information is free to all that wants to read it! Disseminate as you see fit.

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    Well without knowing it, I've been following most of that philosophy. Especially the temp & GPS scenarios.
    Totally agree with the, find the set up & LEAVE IT ALONE part.
    The only time I change a prop during racing is to prop down if the wind & waves blow up, to still allow full throttle with slower speed, & hopefully not flip.
    Of course it doesn't always work. But mostly.

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    As a newbie..I'm still sorting all this out..though I feel I can drive..I'm still learning setups..probably not as easy for some to test as much as others..and I know that in this hobby..well at least here in az..so much wealth of knowledge..don't be afraid to ask questions..Mr david Newland has been a blessing in helping me..even if I beat him..which doesn't really happen..(I'm coming for you dave) i come from car scene where things are different..we run our motors around 160 degrees..and I agree completely with the 125 degree safety mark..u have to realize that the water cooling is just cooling the can..If you could get inside and temp the rotor..i guarantee its way hotter than that..but back to setups.try and repeat..I'm now after last weekend working on my windy setups..lol..

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    Quote Originally Posted by rayzerdesigns View Post
    As a newbie..I'm still sorting all this out..though I feel I can drive..I'm still learning setups..probably not as easy for some to test as much as others..and I know that in this hobby..well at least here in az..so much wealth of knowledge..don't be afraid to ask questions..Mr david Newland has been a blessing in helping me..even if I beat him..which doesn't really happen..(I'm coming for you dave) i come from car scene where things are different..we run our motors around 160 degrees..and I agree completely with the 125 degree safety mark..u have to realize that the water cooling is just cooling the can..If you could get inside and temp the rotor..i guarantee its way hotter than that..but back to setups.try and repeat..I'm now after last weekend working on my windy setups..lol..
    We normally temp the ends of the motors and try and get to the windings as well with a temp gun
    not on the can....
    Jesus is King .......NAMBA20...Caterpillar UL-1, P-Spec OM29, P-Mono DF33, P-Spec JAE, Aussie 33" Hydro-LSH, Sprintcat CC2028 on 8s, PT SS45 Q Hydro, PS295 UL-1 power, OSE Brothers Outlaw QMono 4-sale, Rio 51z CC2028 on 8s

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    I understand that..

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    Well just wanted to add to the debate..i received a new aq 2030..let's just say can't tell any performance difference..so I put it in my p limited cat..didn't change anything prop or setup wise..decided to see if I could make 4 minutes..well I ended up running it for 5 minutes and 45 seconds before it shut off..thankfully right by shore..so only took about 30 seconds to retrieve..pulled hatch expecting to find smoke..but none..i tempted motor..it was at 185..so Def hot..but no fried wires..it ended up lipo cutoff..recharged batteries and went back out..no problems. .I'm impressed

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    Quote Originally Posted by rayzerdesigns View Post
    Well just wanted to add to the debate..i received a new aq 2030..let's just say can't tell any performance difference..so I put it in my p limited cat..didn't change anything prop or setup wise..decided to see if I could make 4 minutes..well I ended up running it for 5 minutes and 45 seconds before it shut off..thankfully right by shore..so only took about 30 seconds to retrieve..pulled hatch expecting to find smoke..but none..i tempted motor..it was at 185..so Def hot..but no fried wires..it ended up lipo cutoff..recharged batteries and went back out..no problems. .I'm impressed
    It doesnt mean that there is no damage, It could be that there is just not enough to kill the motor. There can be a slight deterioration of the lamination on the wire that worsens over time.
    Steven Vaccaro

    Where Racing on a Budget is a Reality!

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    Well we shall see..just ran again..doing testing today..The last version it would've melted the covering on the wires..plan to get at least 5 more runs in today

  19. #19
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    Obviously you could have done some damage to the motor but good stress test none the less. Hopefully most of us won't run the motor this hard as a rule.....

  20. #20
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    I agree..ut i bought this one to test..see what limits are

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