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Old 07-14-2006, 10:40 AM   #361
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Old 07-14-2006, 10:41 AM   #362
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Quote:
Originally Posted by Doug Gaut
Basically with 4 cell touring car there would be:

4cell-mod (slightly slower than current mod- many 19t drivers would step up more than likely)

4cell-19t (about the same speed at current 6cell stock- stock drivers would migrate to this class)

4cell-stock (slow- novice drivers would have their class back)
There will also be a run on 40 tooth pinion gears... cause we all know if they take off 2 cells racers will go up 10 teeth and still overheat everything....
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Old 07-14-2006, 11:52 AM   #363
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Quote:
Originally Posted by Rick Hohwart
The problems are operator error.
Rick, with all due respect, but this kind of argument bugs me a little. If we restrict the discussion to affect solely the 30-50 people in the world good enough to potentially make the A then sure, we could leave it at that. But we aren't are we? The rules we are discussing affect 1000s of drivers across the world. Many of whom either don't know what they are doing (call it operator error if you want but you could also call that bad or at least too complicated products) and cannot afford blowing up an engine or esc on a regular basis. Don't ruling bodies and manufacturors alike have a responsibility to the broader driver base to keep things at least somewhat affordable and driveable?

To add to this, do you think Michael Schumacher will slow down a little if he knows his motor is prone to break if he pushes it too hard? Or do you think he would be in an office shouting at the designers to make sure he can push as hard as he is capable of without the motor blowing up? Ok, this is Michael Schumacher, so probably both. But someone like Montoya or Raikonen...?

Quote:
Originally Posted by tc3team
Question is,are world class drivers (for example) happy to do this?

Dont think so! They want to race the best of everything they have,flat out!

Then you go back to the problem of things overheating and cutting out or breaking down.....
Well, some will and possibly some won't. But to be frank I feel that is less of an issue here. If sponsored drivers (I am one of them mind) have to pay for every speedo and motor they break themselves they will soon be singing a different tune anyway. So where do you think the sponsors will point their drivers if the main events go with 4 cell and 6 minute races and/or some of the other rule changes suggested here.

In my opinion restricting the discussion to world class drivers is not the way to go.
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Old 07-14-2006, 12:23 PM   #364
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Quote:
Originally Posted by vtl1180ny
There will also be a run on 40 tooth pinion gears... cause we all know if they take off 2 cells racers will go up 10 teeth and still overheat everything....
Actually if you overgear this much the only effect is your car will be really slow. The motor will get hot but it not that bad.

Quote:
Originally Posted by tim.walden
Less Volts or More an alternative view.

If we believe that 4.8volts and 4.2Ahr is enough power for 5 minute racing then we are planning to average 50 amps producing 4.8 x 50=240 watts of power. Now using 11.1 LiPoly we would need to average only 240/11.1=22 Amps for the same power.

Heat, which seems to be the problem, is generated by power loss which is proportional to Amps squared so 22 x 22 compared to 50 x 50 is over 5 times less heat with 11.1 LiPoly than with 4.8 NiMh.
What you say is true in applications other than R/C cars. In R/C aircraft I use 11.1v packs all the time. However, I am aware of the wattage limits of my motors and I gear/prop my planes to stay within the limits.

Racers will run the motors beyond thier limits. 11.1v means racers have access to well over 500W. Modern open endbell 540 size motors are at their limits just under 300W.

The point of voltage reduction is to bring the power sources output in line with the capabilities of the motor.
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Old 07-14-2006, 12:47 PM   #365
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Quote:
Actually if you overgear this much the only effect is your car will be really slow. The motor will get hot but it not that bad.

How can you say all will do is make the motor really hot? Overgearing draws A LOT OF AMPS!!!! Voltage is not what's killing ESC's and Motors, Current is!!!

I wish my laptop hadn't of died, I did some gearing testing a while ago with a voltage and amp sensor and all the data is on my now defunct laptop.

The guy who sated raising the voltage would potentially cure the problem is partially correct... If we take off 2 cells the initial amp draw during accelleration is going to go way up, especially when you ask the guys who have tested 4 cells and they all say they went with a bigger pinion to make up for the 2 lost cells.
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Old 07-14-2006, 12:47 PM   #366
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Quote:
Originally Posted by tonyv
Rick, with all due respect, but this kind of argument bugs me a little. If we restrict the discussion to affect solely the 30-50 people in the world good enough to potentially make the A then sure, we could leave it at that. But we aren't are we? The rules we are discussing affect 1000s of drivers across the world. Many of whom either don't know what they are doing (call it operator error if you want but you could also call that bad or at least too complicated products) and cannot afford blowing up an engine or esc on a regular basis. Don't ruling bodies and manufacturors alike have a responsibility to the broader driver base to keep things at least somewhat affordable and driveable?
I think everyone needs to take some responsibility. Drivers have to shoulder some of it as do manufacturers. How many brushed speedos and motors come with fans installed with proper air flow? Almost every pro drivers uses them, but none come with them. Why?

Quote:
Originally Posted by tonyv
To add to this, do you think Michael Schumacher will slow down a little if he knows his motor is prone to break if he pushes it too hard? Or do you think he would be in an office shouting at the designers to make sure he can push as hard as he is capable of without the motor blowing up? Ok, this is Michael Schumacher, so probably both. But someone like Montoya or Raikonen...?
On an individual basis he WILL slow down if told that his car will fail. And surely other teams tune their engines for reliability, not just speed. I am confident that Cosworth (or others) can make the same power and Ferrari or Renault, but I doubt they can do it reliably.

Quote:
Originally Posted by tonyv
So where do you think the sponsors will point their drivers if the main events go with 4 cell and 6 minute races and/or some of the other rule changes suggested here.
6 minute races will bring battery capacity back into the equation in my opinion. Drivers may be forced to control their driving anyway simply to finish the race.

Quote:
Originally Posted by tonyv
In my opinion restricting the discussion to world class drivers is not the way to go.
Agreed. But we must remember that we are not talking about the only R/C racing class available. MOdified should be the best that it should be, but will always be the class that is the most difficult to be competitive in because it will always be the fastest of the touring classes.
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Old 07-14-2006, 01:51 PM   #367
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Rick, it sounds to me like we agree to the same thing overall but are using the arguments differently. I fully agree that modified should be top of the bill and be a challenge to drivers (for me this includes the challenge to make the runtime BTW ). The same goes for F1. With all the restrictions made through rules to F1 over the past decade or two, has it become any less the most challenging 1:1 scale racing class? I don't think it has. Nor do I think making changes to the rules for modified racing (which will indirectly lead to similar changes in stock and super stock) will make mod any less the most challenging class.

Put differently, we are discussing how much of a challenge it should be. Nowadays both for drivers and electronics I believe the class is much more challenging than it was a few years ago. If left unchecked less and less people will be able to drive at this level because they simply aren't good enough, cannot afford to replace broken electronics (which is also a problem in stock and super stock) or both.

But then I think we agree on the latter too right?
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Old 07-14-2006, 01:59 PM   #368
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Quote:
Originally Posted by vtl1180ny
How can you say all will do is make the motor really hot? Overgearing draws A LOT OF AMPS!!!! Voltage is not what's killing ESC's and Motors, Current is!!!
You are half right. To state it properly Voltage X Current is killing our motors by generating more Watts than they can handle.

Current: The amount of electric charge flowing past a specified circuit point per unit time.

Volt: A unit of electromotive force in the Internation System of Units that will produce a current of 1 ampere in a circuit that has resistance of 1 ohm.

Watt: The power dissipated by a current of 1 ampere flowing across a resistance of 1 ohm

Any value of Amps at a lower Woltage generate fewer Watts of energy. Fewer Watts of energy dissipated will yield lower operating terperatures.

Thus any motor wether it is highly geared or even shorted will generate less heat at a lower voltage.

Thats how I say it....

So we can fix the problem we have with a reduction in:

Voltage - Easy, revemove a couple cells, cheap, no technology investment, easy to tech, lower costs to racers.

Current - Difficult, create current limiting devices, expensive, new technologies must be developed, potential new way to cheat, hard to tech, hard to fit on the chassis, increased cost to racers.
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Old 07-14-2006, 02:04 PM   #369
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Quote:
Originally Posted by AdrianM
Thats sounds so easy but its not. I am surprized Rick replied with a to this post as Rick shut down a speedo in one of the Triple A's at the Worlds last week. This moved him from middle of the pack to 10th.

It is againt human nature to give up power on the track to finish races. If you do you are gaurantying you will not make the podium. You always have to run the agressive setup and roll the dice that it holds togehter...Right Rick
if a guy who had a speedo shut down at the worlds is advocating driver control vs. limiting cells, that should tell you something.

why on earth should the many who haven't suffered thermal shutdown change so that the minority who have don't have to excersize a little restraint?

lets use the worlds as an example... the drivers are naturally going to drive as fast as they possibly can. it is the motor builders responsibility to provide them with enough power to do that and be competetive, but not so much they overload their esc or motor. at that level of competition, why is it that some drivers had 0 problems while others did? maybe the guys having problems need to re-evaluate the equipment they're running if the only way to be competetive means there's a high risk of failure.


but i do agree that running 4 cells will reduce temperatures and have no negative impact on run time. i just don't think it's necessary to cater to the needs of the few.
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Old 07-14-2006, 02:26 PM   #370
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Russ - Everyone is having problems to some degree. From stock racers that need to cut comms and install new brushes EVERY RUN to stay competative at club races to Pro's at the Worlds throwing winds at 60,000rpm and shutting down speedos.

FYI, This thread was started to report the fact that all motor builders said something needs to be done at the IFMAR AGM meeting last week.
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Old 07-14-2006, 02:32 PM   #371
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[QUOTE=Rick Hohwart]I think everyone needs to take some responsibility. Drivers have to shoulder some of it as do manufacturers. How many brushed speedos and motors come with fans installed with proper air flow? Almost every pro drivers uses them, but none come with them. Why?


The best post so far.
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Old 07-14-2006, 02:35 PM   #372
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Quote:
Originally Posted by tonyv
Rick, it sounds to me like we agree to the same thing overall but are using the arguments differently. I fully agree that modified should be top of the bill and be a challenge to drivers (for me this includes the challenge to make the runtime BTW ). The same goes for F1. With all the restrictions made through rules to F1 over the past decade or two, has it become any less the most challenging 1:1 scale racing class? I don't think it has. Nor do I think making changes to the rules for modified racing (which will indirectly lead to similar changes in stock and super stock) will make mod any less the most challenging class.

Put differently, we are discussing how much of a challenge it should be. Nowadays both for drivers and electronics I believe the class is much more challenging than it was a few years ago. If left unchecked less and less people will be able to drive at this level because they simply aren't good enough, cannot afford to replace broken electronics (which is also a problem in stock and super stock) or both.

But then I think we agree on the latter too right?
Yeah we agree.

I just want to make sure that thorough testing is done before any changes are made. My impression at the meeting was that "we need to change to 4-cells, then figure it out as we go" rather than doing extensive testing first to be sure that 4-cells is the correct decision.

There will possibly be some very serious consequences of a change at the hobby shop level. Sport packs are 6-cells. They need to be as the cheap cells to not provide a lot of power. An IB4200 4-cell pack will probably run faster than a $20.00 sport pack. A 4 cell cheap pack will be totally inadequate. And what about off-road? We know people can be fast with fewer than 6-cells, but must fewer be mandated? Can they run 4-cell too?

With different rules for the two major electric classes, and separate specs for entry level batteries, hobby shops will have to stock more items. They can barely stock the right stuff now. Crossover participation will also be more difficult and costly.

From the business end of things, I truly belive the health of the r/c racing hobby lies in the 6-cell standard. I also think slowing electric cars down will make nitro more appealing (to newcomers) than ever.
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Old 07-14-2006, 02:36 PM   #373
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Quote:
Originally Posted by AdrianM
Russ - Everyone is having problems to some degree. From stock racers that need to cut comms and install new brushes EVERY RUN to stay competative at club races to Pro's at the Worlds throwing winds at 60,000rpm and shutting down speedos.
As long as it is "Racing" that will never change. We ALL have to understand that.....

FWIW I agree with Russ, MOST of us are not having these problems. Why should we HAVE to change to make the 40 or so at the Worlds happy?
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Old 07-14-2006, 02:38 PM   #374
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The stock and 19-turn motor rules should be changed so the timing limit is 5 degrees.
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Old 07-14-2006, 02:59 PM   #375
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Quote:
Originally Posted by Rick Hohwart
The stock and 19-turn motor rules should be changed so the timing limit is 5 degrees.
That was what i was gonna suggest i wish Big jim (R.I.P)was still around to stick his nose in this arguement. He was suggesting stuff like 5 degrees timing four years ago as racers were just pushing the motors too hard to gain the edge of their fellow competitors. That why windings were blowing and comms needing skimming etc. With mod he wanted to change the magnets and go to a five rotor armature to compete on equal terms with brushless but that not the case as the ESC for brushless can't cope with the heat and the battery power. You guy should read what big jim has said in the rccars.com forum
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