bender

iTrader: (4)

Whilst I agree that limiting the cells isn't my idea of Mod - you can't simply tell the motor and esc manufacturers to hurry up and catch up.

Don't you think they're already trying to release more reliable systems?

The problem is that is that the rate of battery development is MUCH quicker than the rate of motor/esc development.

Don't you think that if the motor/esc guys could develop stuff faster then they would?

We need to stall the development of the batterys until the motor/esc guys can catch up - the question is how?

The people who want to switch to less cells at least realise that this will "stall" battery development (in terms of voltage) for a while - even if in the long term it's not the final solution.

CAi

Well...we are using LRP brushless with sintered rotor and LRP speedo.

And no problems at all! We havent touch the motor since about 100 runs.

Where is the problem? I can ask. Why is sintered not legal 2007 decided by EFRA 2 months ago???

ottoman

iTrader: (13)

Actually I wonder if they are working on better ESC's. Most ESC companies are fairly small... from what I can tell. I believe most of their engineering capabilities have been focused on the brushless tecnology, at the expense of the brushed ESC. Or maybe they feel there is no future (or $$) in brushed esc's so they have pretty much stopped development on them.
Either case it seems we are stuck for a while until they get brushless were it needs to be to handle todays modified racing. Now instead of just developing a better (brushed) ESC they have a more complicated brushless ESC and a motor package to develop... this could mean it takes more time to get it right

Bob-Stormer

iTrader: (8)

Actually, if you stall it, they haven't exactly caught up, and the problem would still exist.

It's taken like 15 years to double what we had in cell mAh ratings, that's not exactly keeping up with your computer processor kind of pace. I think the processor in my current personal machine is 100 times faster than what I had in 1988 or so.

15-20 years to make it happen. That's not exactly a pace that's hard to keep up to.


Although I haven't tried it, I'd be willing to bet most of us could still do well club racing with a 15-20 year old ESC, AND, it's likely to survive. Anbody think a novak 1 would survive in a current mod offroad buggy or touring car with a 10-14 turn motor? I bet offroad, probably. Might get pretty warm in touring. I bet it would survive. What is that "REALLY" saying about that part of our industry? No offence intended to that segment of our industry. To much concentrating on features, and not enough on "in-destructability". I might have invented a word there....

*SBH*

Hi guys
Just some info. I became more and more interested in trying 5 cells after reading all this, so yesterday I tried it. Normally I race in the modified class, but since my last race was a club race with 19turn, I kept that motor in the car.
I had 3 old packs with 1 broken cell I could use for this test. The voltage of these cells are 1.207 - The cells I normally use and which I compare to is 1.251.

The only thing I changed was removing 1 cell from the pack. No further changes, so the only weight reduction was the 65grams from the cell.
First run out was only 0.3 sek slower pr lap than with 6 cells, overall after 5 min was 6 sek slower. - After the race the motor was a lot cooler than usual.
Next battery I tried to gear up 2 teeths on the pinion, and the result was amazing. A lot of the speed was back, and the best lap time was only 0.1 sec slower than with 6 cells, and remember these cells were still lower volt and higher resistance than my normal cells. - After 5 min of racing the overall time was 3 sec slower than with 6 cells!

It was really funny to try this experiment, and next time I will try the same with a modified motor. The other drivers were quite amazed about the small difference in lap times, and so was I actually. And now I have 2 different places to install my batteries, back and forth

Try it guys, its quite fun

Søren

Ben.C

You've used 3 old packs...Imagine with 3 new packs...

TRF415boy

it's not been decided 2 months ago but 3 weeks ago. AND there is a rule that says any major changes like this one will only be applied 12 months after the decision has been taken, to give enough time for the manufacturers to come up with appropriate products.

Now since you know better than anyone here, and you think no one blows brushed and brushless speedos and motors, why don't you go and manufacture your own stuff and sell it ?

Oh and by the way when I say blow up, I MEAN blow up as in terminated, boom, big smoke or wind thrown or magnet in bits...

Giuseppe d.

Maybe because this way sponsored drivers may keep the gap between them and "normal" racers?
I know this is a malicious thinking, but this whole thing seems to me so illogical that I'll take in count any scenario..


The real problem in my point of view is that the Brushless IFMAR/EFRA specs were OLD yet when they was written down. They took one manufacturer motor, they misured it, ET VOILA', we had the brushless rules.. the sad thing is that this motor was a design issued years before when batteries were much less powerful.

The way to solve thermal problems with brushless -in my point of view- are new motor specs, allowing for example wider magnetic rotors, sintered rotors, delta windings etc.

I understand that reducing cells number is the fastest and easier (but easy for who??) way to solve, but this have to be only a temporary solution..

Anders Myrberg

..and 1350 gram...

Giuseppe d.

tha way to reach 1350g from actual cars may be very expensive, in my opinion.
Removing one cell will take away about 60g, and the ramaining 90g ??
Brushed sistem are light, but brushless are heavy... will we see soon some titanium bulkheads, screws? I think so. Is this cheap? we'll see.

Anders Myrberg

I´m not 100% sure her, but what I heard from my boys is that they already put quite a lot of led on there cars (Xray), and that they will be somewhere close to 1400 without it. They will most probably not chase the rest. Anyone can save some by using a Lightweight body. Today, drivers put 3-4-5 fans, big heatsinks and sometimes reciever battery being way over 1500 without hear anyone complaining about overweigt. And this at the World Championship.

The best is most probably to see what happends during the next months or so. It might work great. Who realy knows?

Eirik

Søren, Seriously dude, something must be wrong with your car that can't handle all that power, and 19t as well, Hmmmm.

You removed almost 17% of available power and your almost as fast??
This must be on a tiny track or something, because when we tested this here, the "power" was gone, top speed was ok, but it was really mellow!!!

When I swithc from my practice packs to my race packs I am about 2/10sec faster on an average indoor carpet track! This has ALWAYS been the case!!

Trust me, 6cells is faster, no doubt!!!
We can run a test at Staffanstorp next summer if you like and see who has the most fun, you with 5cells and me with 6cells

Bob-Stormer

iTrader: (8)

I thought I might add, that as soon as you see everybody on board with their newest "sensorless" brushless speedos, you will see the changes that needed to be made. I believe Novak will be sensorless by next summer, as will most of the others, in addition to better current and heat carrying capacitys.

Being as this was an EFRA decision, what was Jurgen's opinion of going to 5 cell?

Ask Dumas how his new Tekin brushless stuff is doing. So far, as I am told, he is quite happy with the results, issues with brushless SOLVED, and Dumas is no club race rookie. These comapnys aren't completely blind to making brushless speedos and motors "tougher". How many racers can thermal and lose a race with your stuff before they switch brands?

The manufacturers are getting caught up just fine. The batteries are just fine, and the brushless esc folks are getting caught up as well. But at this point, of the components, the esc and brushless motor are the weakest links.

Changing to 5 cell was not the answer, in my opinion. Fixing the problems with the escs and motors that could not take it, that would be the answer. And it's being addressed.

The only speedo I've seen blown up this last year was one of mine. it was in an RC18, and I kept driving it reverse up against the thermal shutdown for an entire race, until it finally smoked. No fault of the esc...

For those that feel to many speed controls over there are "blowing up", I'd be interested in a few more details on that. Any particular brand? Was it the guy that won, or the guy in last? Just how many is "to many"???

Just how many speedos, physically "blew-up" as the result of the batterys, at any major race last year? Cleveland is this weekend here in the States. I think it's safe to say that some of the best drivers in the world will be there. How many speedo's will in the words of the 5-cell promoters, "blow-up" at this event? I suspect there will be a great deal of "testing" going on at this event. Be fun to hear about the results.

Bob-Stormer

iTrader: (8)

in a Nutshell.

I personally am for whatever it is that allows me to turn faster and more consistent laps on the track. I don't care how many cells it is, allow me to make the decision on how best to manage the power. And by "ME", I mean "Joe Racer", or the average "Svensson"

That said, I don't have a problem with 5-cell, 4-cell, 10-cell, whatever. Not one little problem. If one of those will make me faster, and it's legal, I'll find it and use it.

My gripe with this is in blaming the batterys for what others here are saying is a problem with a few motors and speedos not surviving...

THE WRONG ITEM IS BEING ADDRESSED. The batterys work very well, as it would seem. WHY NOT FIX THE MOTORS AND SPEEDOS!?!?

Just how epedemic a problem was this anyway??? I don't recall hearing about any races, anywhere in the world, where this over-powered problem led to 10-40 fires during the main events at any event, as cars burned to the ground with blown speedos.

Any at Vegas? Snowbirds? Burned to the ground, blown out!? Even if there were 2 or 3, That's not any kind of problem. That's racing. Who's to say an impact didn't lead to the problem with that one? OR a problem induced by the consumer?

Anybody from the Vegas or Birds races see a lot of blown up stuff? Physically blown up and burned down.

PitCrew

I was at Vegas.

I personally saw one battery explode, and one car catch fire.
May have been more, don't know.

I don't think the batts are the problem either. Most speedos are made to run 4-7 cells. We are running SIX so it should NOT be a problem.

There is nothing really wrong with the motors either. Just that racers are trying to squeze every last bit of power out of them. Its pretty easy to de-tune a motor. Just run harder brushes with less silver in them.