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Old 10-03-2008, 04:30 PM   #46
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You're totally right in theory. In practice, it won't happen IMHO. The drivers will look at what the top guys run, and will decide they have to run same. They'll either do that, and break stuff, or decide they don't want to go down that road and not even try. It happend with 6 cell brushed mod. People stopped racing it rather than fit a 10 turn.
What's the difference with what's going on now? Aren't the regular guys also looking at what the top drivers are running and aren't they trying to do the same with 5 cell nimh and 2.5, 3.5, 4.0 motors already? If regular drivers are trying to emulate top guys using 2.5 and 5 cell nimh and are having trouble controlling the cars, and crashing, might as well do so with Lipo They'll have more time ont heir hands to actually work on their cars and work on their driving skills with Lipo, and eventually get better a bit quicker...it's the better option
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Old 10-03-2008, 07:18 PM   #47
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I have to agree with Mat. From what i see, USA is all about stock.

Where i live everybody wants to run modified. IMO, the only reason why some people race stock here is because it is the only place where Lipo is allowed.

I understand this sentence alone is a suficient argument in favour of alowing lipo in modified, BUT i dont think runing lipo with unlimited motors will work. The power is insane fast. Only a few will take advantage of that power. The others will powerslide like crazy.
Last year i raced modified with 6 cell, and i dont miss that one bit. New belts and pulleys every race. Blades every 5m on track. 5 cell made things much easier.

I understand nimh are way to much trouble, thats why i think A123 cells are the best option for modified. Same voltage as 5 cell, faster charging, far easier to tech.
my .2 cents
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Old 10-04-2008, 05:32 AM   #48
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Yeah sure, people want to emulate the top 10 and run 3.5, but the car is still driveable - that is entirely my point. When they emulate if we are running 4 turn and LiPo, car won't be driveable IMHO and that's where it all goes wrong.
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Old 10-04-2008, 06:29 AM   #49
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I understand nimh are way to much trouble, thats why i think A123 cells are the best option for modified. Same voltage as 5 cell, faster charging, far easier to tech.
my .2 cents
If you wanna run A123 cells, you have to allow just one (non-adjustable) charger. You can overcharge A123 cells easy to 4.2 or higher voltage per cell (instead of 3.6V). So, some guys will race with much more power, but have to buy new cells every race.
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Old 10-04-2008, 08:00 AM   #50
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If you wanna run A123 cells, you have to allow just one (non-adjustable) charger. You can overcharge A123 cells easy to 4.2 or higher voltage per cell (instead of 3.6V). So, some guys will race with much more power, but have to buy new cells every race.
Have you tried that? I did and found the voltage will drop as soon as you disconect the charger...

In any case, how is that different from Lipos? :P
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Old 10-04-2008, 08:02 AM   #51
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And how is that different to LiPo and NiMh? All cells will have this problem! The big advantage for NiMh is that if you charge more, the voltage drops! We will never stop anyone who wants to win spending more money than someone else who wants to have fun - Laws of Racing!

A123 cells are safer than LiPo, and come in their own 'case'. The Panasonic 2.4v cell is much the same. LiPo is a stepping stone to better cells, but we will have to go through a lot of change before we get there. The problem is that during times of change, people leave RC. It would be better to wait for three years when all the new cells are around, and we can make the best choice, rather than changing many times in three years.

Today's EnerG/EP and Orion SHO cells are back to what NiMh used to be - punch, volts, last a whole season at the top and another season at Club, no storage problems and easy to use. Rather than allowing LiPo, we would all be better off if EFRA banned IB. Just a thought...
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Old 10-04-2008, 09:29 AM   #52
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Have you tried that? I did and found the voltage will drop as soon as you disconect the charger...

In any case, how is that different from Lipos? :P
The difference is, that Lipos burns

I charged a 2S2P A123 pack one time with 3.6V, an one time with 4.2V Cutoff-Voltage. I discharged them at 20A and there was a difference of approx. 0.2-0.4V (0.1-0.2 per cell)
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Old 10-04-2008, 09:52 AM   #53
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I havenīt seen anyone using 2.5t and five cells. Thatīs not realistic. Most drivers use 3.5t or above and itīs plenty fast. Switching to five cells here in Europe have really put a boost into the dying modified class. I think going from 6.0 to 7.4V maybe is not the way to go. A 6V Lipo battery would be a great compromise.

I think EFRA most consider safety aspects with Lipo and so on just like ROAR have done in the US.
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Old 10-04-2008, 10:29 AM   #54
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Thanks everyone for your opinions.

I would like to point that people that are arguing against the use of lipo with modified motors are doing it in most cases pointing the use of lipos and 2,5T brushless motors.

First point. those motors are not intended for the use with 7,4v lipo cells.

Second. If any driver want do use them, I believe, he should be allowed to do it. He will be at the hedge of burning the motor at any moment, more, his car will be just a little less that undrivable, he will ruin his tires very fast, I believe all the other drivers in the same main will be happy. He will discover for himself he will drive faster with less power, like the 5cell drivers have done in the past.

If the track is big enough to make better times with those motors, then all the other drivers can do it too, what is the problem?

The use of a very low turns motors with 7,4v lipos would be like the use of a very powerful IC engine in 1/10-200. The rules can limit the Nitro quantity in the fuel, but cannot limit the number in turns of the neddle. Everybody knows if the the neddle in very close the mixture will be lean, very lean, the car will run very, very fast but the motor can have a failure at any time. Possibly a driver can use a new motor in every heat and use the mixture very lean, so possibly the rules should think about the number of motors used too?

Another important thing, beside 2 or 3 drivers here, all the others are already using 7,4v and motors with no limit in club racing. everybody is happy with it, so, should not the rules go towards that direction?
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Old 10-04-2008, 12:38 PM   #55
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ROAR is the only body of organization that allows lipo's. Follows many af the rules under IMFRA. ROAR has two lipo,s approved that are 5400mah. Really should limit the Mah on lipo's. 5400 IMO is too much. 5000 they should limit, the lipo's or limited to class stock or modified on mah @ 7.4v. ROAR has limit on charging lipo's on temp, which should be followed, cuz of early problems of explosions. Safety of all NiMH and lipo's follows. All lipo's are being checked By ROAR after charging for over charging. Safety of the lipo's to be Checked by ROAR, and ROAR is the testing before lipo's legalize by all oranizations. Give it a year, they'll be legal.
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Old 10-04-2008, 01:07 PM   #56
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ROAR is the only body of organization that allows lipo's. Follows many af the rules under IMFRA. ROAR has two lipo,s approved that are 5400mah. Really should limit the Mah on lipo's. 5400 IMO is too much. 5000 they should limit, the lipo's or limited to class stock or modified on mah @ 7.4v. ROAR has limit on charging lipo's on temp, which should be followed, cuz of early problems of explosions. Safety of all NiMH and lipo's follows. All lipo's are being checked By ROAR after charging for over charging. Safety of the lipo's to be Checked by ROAR, and ROAR is the testing before lipo's legalize by all oranizations. Give it a year, they'll be legal.
There is no need for ROAR or any sanctioning body to create a mah limit. Yes there may be a couple of approved ROAR packs that exceed 5000mah but the hard case size for the ROAR rules are the true limiter of how much capacity can be stuffed into a ROAR legal lipo battery. If any sanctioning body were to enact a MAH limit in lipo they would have to define a testing method to verify that capacity in homologation otherwise the capacity limit means nothing. The kind of testing required would be very time consuming.
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Old 10-05-2008, 06:17 AM   #57
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Yes, I believe ROAR have done it right. Just limiting the size.

I think that should be extended to the motors too, just limiting the can size, and then the manufacturers will take the maximum advantage of their technology to give pilots the best possible motor.

Perhaps in a near future.

And congratulations to ROAR for the move to lipo.
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Old 10-05-2008, 11:56 AM   #58
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LiPo + 5t motor = OK

With Nimh cells this sport is gone!

No normal level driver has the money to buy new cell's every second month and wich of 1-3 cell is allready dead when bought!!!
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Old 10-05-2008, 01:10 PM   #59
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Now that is the sort of uninformed rubbish that needs to be stopped right now. the problem with NiMh has been a problem with IB. The EnerG and EP cells are back to where NiMh was three years ago - solid, punchy, long-lived and easy to use. In Europe, we also have the Orion SHO, a 3700-based cell that is even better than those two.

Secondly, the battery performance is far less of an issue than it used to be thanks to BL motors. It appears that LiPo performance is pretty much level, since no one battery has been favoured. In which case, teh different speeds we see from cars using LiPo must be down to gearing and timing on BL. This is what we find in 12th - the motors can be made to go as fast as each other when timed and geared correctly, irrespective of battery condition. Cells bought last year are giving me as good a lap time as cells bought this year.

I understand that people like their LiPo, but it is not suitable for 12th, Oval, TC Mod (in Europe) and numerous basher/RTR cars that are all over the shops, and are the main route for people to come into competitive RC. What you're saying is not only not true, it closes out the lifeline we need for the continued growth of RC. If you're not using NiMh today, then please keep your opinions to yourself. Thank you.
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Old 10-07-2008, 12:29 PM   #60
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Seems like there will be new rules proposed to allow lipos at EFRA AGM.

Proposed by: B.R.C.A Great Britain

and

Proposed by: NMF/RC Norway
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