FE P-Limited Rules NAMBA and IMPBA and best choices!

[lohring]

The UL-1 ESC is great, but will eventually be fried at the currents that can be run. The question is what do you want to be the fuse. The Turnigy 120 Marine ESC will run for years with the motor as the $80 fuse. The UL-1 ESC costs $89.99. The Turnigy 120 Marine costs $58.32 from the US West warehouse. Feel free to require a more expensive, but lower rated ESC that will need to be replaced as often as the motor.

Lohring Miller

 

[RonShaw]

Good points Lohring. I think limiting the battery capacity to 4S and a total mAh rating of 6000 or less (single or dual pack), and limiting the motor size will be the easiest way to keep "hot" setups from showing up. This would truly help make this class as popular as the B stock class.

 

[HOTWATER]

Just want to say that I have yet to see or hear of a UL-1 ESC used in P-Lim.Dist.12 heat races being fried...pretty sure anyone that is using the UL-1 esc is not expecting SAW runs. If you want something faster to race with then the obvious thing to do is to move into a FULL P setup...or Q...or....

 

[Doug Smock]

You're pissing up a rope Kent! LMAO

Ron check out the pile O fuses on the NAMBA Nats, thread on OSE!

Promote P Tunnel Ron!!

Later!

 

[HTV Boats]

I would prefer to see a "Q" class tunnel. Larger hulls, more seaworthy, and less amps for ESC's to process. Same cost a full P for the most part. A 1521-1527 motor on 4S can really pull some amps. On 6S you can get by with a T-180 and speeds equal or better than a .45 nitro. It's already in the book and available for records.

Mic

 

[Doug Smock]

I would prefer to see a "Q" class tunnel. Larger hulls, more seaworthy, and less amps for ESC's to process. Same cost a full P for the most part. A 1521-1527 motor on 4S can really pull some amps. On 6S you can get by with a T-180 and speeds equal or better than a .45 nitro. It's already in the book and available for records.

Mic

What he said Ron!! And don't look back!

 

[Darin Jordan]

I really should just stay out of this, but what the hell.

P-LTD is what it is. It should never have been made a National Class as is. Hindsight is 20/20 I guess.

Other than people pushing the motors too hard, which is what that pile of burned motors was about, the only REAL problem with the class as it sits is this ONE Question :

CAN IT BE TECH'D?

Like mAh limits, KV limits, cost limits, or any other limits people keep trying to propose, the answer to anyone who knows anything about the subject is NO. There really is NO reasonable way to tech the present NAMBA P-LTD rules.

That said, it's the most contested FE class in NAMBA, and draws the most interest. On a CLUB level, it's an excellent class to have around. There, a more "friendly", less stringent teching is fine. On a NATIONALS level, however, well....

Our club, as well as at least one other I immediately know of, are considering switching to a physical motor size restriction instead. 36.3mm x 61.2mm, specifically. If the motor fits that envelope, it's legal. Don't care about cost, KV, etc.

THAT can be tech'd, and would still provide a truly LIMITED power class that doesn't rely on part numbers, RTRs, or anything of the sort. JUST like ALL of the other FE classes, you get to pick the power system you wish to try. Think you can make a 3000KV motor work on 4S for 1-Mile, go for it. JUST like ALL the other power classes, you'll find the PRACTICAL LIMIT.

And, because of the PHYSICAL SIZE restrictions, there is an absolute power limit for the class. P-Lite, if you will, though Limited still makes sense.

That seems to be the ONLY way to truly provide a more restricted version of P (4-Cell) that can actually be teched.

 

[Darin Jordan]

Oh, to answer Ron's original question, I don't know about what ESC rules IMPBA runs, but my Lynx and my Dragon M11, arguably the most competitive FE P-LTD OPC Tunnels in NAMBA at this point, both eun Castle ICE100 ESCs, and AQ UL-1 motors.

The Lynx pulls around 83-103 AMPS, and the Dragon M11 about 95-115A, both with the same prop. Not sure why the difference.

 

[Darin Jordan]

I'm also going to say this.... there seems to be a lot of , well, gloating above, aimed toward NAMBA, but you know what.... you don't hear us bitching about being able to keep FE classes working for NAMBA.

Our rules aren't perfect, but our FE numbers are as strong as ever

 

[Doug Smock]

Not sure where you saw gloating aimed toward NAMBA Darin?

"P-LTD is what it is. It should never have been made a National Class as is. Hindsight is 20/20 I guess".

Looks to me like we agree. Exactly the point I was trying to get across to Ron.

Thanks for the help.

Later fellas!!!

D.

 

[Kris Flynn]

I wonder if before the start of a large event (say nationals) the P Ltd motors could be handed out to competitors (part of the entry fee for that class??) with a marking on the case or what ever

the person can select any of the (4?) motors and the club purchases them at a discount?

always going to be people pushing the envelope or (even cheaters)

Thought you were done with this a page ago Doug haha

 

[Darin Jordan]

Honestly, Kris, if it comes to having to go to those lengths, I'd rather the class die. That's way to much hassle to me, especially when such an elegant solution exists that would end the babysitting of these rules once and for all...

Any motor not exceeding 36.3mm diameter x 61.2mm length.

Done.

 

[DPeterson]

"Arguably the most competitive FE-LTD OPC Tunnels in NAMBA at this point." Toot toot! Darin - you really should travel to some races before you go and toot toot your own horn. Always a learning experience when you leave your home pond.

Quick note to anyone in IMPBA looking to piggy back off of NAMBA rules. Think twice and think harder. Been one mistake right after another.

 

[Darin Jordan]

Not going to bite, Peterson. If every NAMBA P-LTD OPC record, a Nats Championsip, and the fastest OPC Tunnel EVER to do a 2-Lap time doesn't give me SOME measure of experience to talk on the subject, then I don't know what does. Your part of the RC world doesn't have a monopoly on OPC Tunnel talent, and I'd take that a step further to say that the the fastest other OPC Tunnel in P-LTD is Jordan Enns from Vancouver, CA.

And Doug Smock, this was the crap I was referring to, not anything you posted.

Say whatever your bitter self wants to say, Doug P. It's inconsequential to me, and since you don't race NAMBA, and choose instead to just smash on it whenever you get the chance, we'll take your opinion for exactly what it's worth.

 

[Kris Flynn]

My question for you (who ever wants to) is....WHY are people entering the P Ltd classes in high numbers? Must be something good going on.

 

[Don Ferrette]

My question for you (who ever wants to) is....WHY are people entering the P Ltd classes in high numbers? Must be something good going on.

It cheap, just that simple. To be clear- I have ZERO issues with the class being done at local levels, D12 has been running it for a few years now with great success. I do NOT want to see it as a National class as then it becomes eligible for records............ hard lessons already learned about tech'ing "spec" classes, no desire whatsoever to go down that road again.............

 

[moparbarn]

I don't run FE, but what Darin says makes a ton of sense to my ignorant azz........IF ya'll want a Nat'l. P spec/limited class, spec can size & (I'll add) ESC AMP LIMIT - say 120(??). Simple to tech, affordable & readily available power systems, any manufacturer as long as it fits.

To add to the D-12 P Limited racing, we run them in B outboard tunnel, B mono, B Sport Hydro & B Rigger as combined nitro/fe heats. EXCELLENT parity & better entries total per class = FUN, competitive racing. I like it!!!!

 

[HTV Boats]

Wow Doug and agreeing on a couple points. A single motor 36.3 X 61.2 mm rule would be easily enforced and open up a lot of choices that may be keeping non AQ fans from running. Speedy's could be left open as a 200amp or more would add weight which batteries larger than 6000ma also do. Adds reliability but may slow you down. If NAMBA is working now would this kind of rule change anything or add flexibility on their side?

Mic

 

[lohring]

We tested Q tunnels a few years ago. The goal was to find a spec style setup that would be about the same speed as a 7.5 nitro tunnel. Brian's Leecraft was actually faster than a 7.5 mod tunnel as he proved at the Fremont Grand Prix. We were hoping Tower would come up with a 22 volt motor like the series of 14 volt motors. The costs were more than P limited, but were reasonable. As was pointed out, it's preferable to run higher voltage at a lower current for power. Just about all the components in our electric power plants are current limited.

Darren, I would add a weight limit as well as a size limit to your motor rules. Otherwise that would make a good motor rule, especially if Tower has issues with the UL-1 motors.

"[SIZE=12pt]I did not say the power is directly influenced by the motor size. Basically only the max. torque is influenced by motor size/weight. But mech. power is torque * rpm, thus the max. power rating is derived from the max. rpm and thus only valid at max. rpm! Be aware of that.

There is a general rule of thumb for electric (BL) motors.

Power at max efficiency [W] = C * weight [g] * rpm / 10000

C is a constant which is basically 1 for BL motors of 600 size (LMT 19 series, Hacker B50 series). It's smaller than 1 for smaller motors (aprox. 0.85 for 480 size) and bigger for bigger motors (like 1.2 for LMT 22 series). This constant describes that for smaller motors more weight is "wasted" for the case."[/SIZE]

[SIZE=12pt]Lohring Miller[/SIZE]

 

[Darin Jordan]

The questions again arise:

1) Speedo Limits- HOW do you TECH that, at NATIONAL level event?

2) Motor Weight Limit- Same question...

The more words you have on paper, the more tech-ing becomes an issue.

Also, nobody worries about motor weights, or speedo limits, in ANY other NAMBA class. We are already absolutely limiting the amount of power that is going yo be available by physically limiting the motor size. Why are further limits necessary?