It has become apparent in recent months that the advent of new very high voltage cells is causing carnage – particularly in the modified ranks.
Whilst at club level in Queensland there haven’t been too many dramas, at the big national meets it is common to see motors detonate, speedos “release the smoke” and more. The power available is making modified both (a) extremely difficult and (b) unreliable at times.
So what is to be done?
One option of course is to do nothing. To insist that its up to the drivers to gear and/or drive more conservatively. That is a genuine argument, but to me falls short because it leaves the advantage to the wealthy racer who can afford to risk blowing speedies and motors in pursuit of the extra performance.
Another option is to extend race times – maybe to 8 minutes. This has potential, but will bring back run-time into the equation. For the first time in living memory mod touring cars can now race without runtime issues, and I’m not sure we want to go back to the “good” old days.
A third option is to reduce mechanical or aerodynamic grip. Lower grip equals lower load on motors, and probably more conservative motor choices. That’s a genuine option and a 2wd touring car sounds pretty appealling to me. Not for everybody though, and making the cars harder to drive is probably not the ideal solution.
Which leaves us with reducing the voltage. Dropping touring cars (and at the moment I’m talking specifically modified class) to 5 or even 4 cells will reduce heat, reduce wear and tear on motors and speedos, potentially reduce costs and so on. The cars are probably only a little slower, and still well quicker than 19T – our next fastest class.
Personally, I’m in favour of it. Anything to help (a) reliability; and (b) encourage and increase participation; is to my mind a good thing.
The question is: what do you think? Leave your thoughts below….
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20 responses to “4 or 5 Cell Touring Cars?”
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on wednesday i tested with 4 cells at hobby station during the day and then through the racing at night.
the first few runs in practice were spent working out gearing, getting used to the slightly different feel of a lighter car and basically just putting in alot of laps to bring the grip up for racing in the evening.
the motor setups i started with
6 cell – V2, 7×1, 12° timing, geared 22/104 (10.3).
4 cell – V2, 7×1, 18° timing, geared 25/104 (9.1)
by the time the grip had come up after having multiple 4 cell runs and a couple of 6 cell runs i was actually surprised in the difference in tempreature that the motors were coming off the track. i was expecting the 4 cell motors to come off the track cooler but not on average about 25°C cooler!
in the first round i ran with the 6 cell setup to put in a time against which 4 cells could be compared against. was a nice clean run with no mistakes.
round 2 i ran with the above 4 cell setup. another nice clean run, no mistakes.
the motor definatly didn’t sound as fast as the 6 cell setup during the race from the drivers stand but i was quite eager to see the sheet after the race.
best lap was 0.10 of a seccond slower and the overall race time was only 2 secconds off what i had set in the first round.
round 3 i tried gearing up 1 tooth to 26/104 (8.75). the car felt a little slower on the track and indeed the time sheets agreed. again the best lap was only under 0.20 secconds off what i had set in the first run with 6 cells, but this time the average lap was a bit slower. in a way this was good as i was starting to get an idea for the gearing window with 4 cells.
round 4 dropped 2 teeth to 24/104 (9.5), so now geared 1 tooth under what i had origonally started with. actually set my fastest lap of the night in this race. undoubtedly because the grip had continued to improve as the night went on. but this gear ratio definatly feel the best of all the ones i had tried over the night.
after racing i pulled the motor i had run with 4 cells apart and despite all the runs over the course of the day it looked very good. the brushes showed only the slightest change in colouration towards the face of the brush. basically it looked like i could give the motor a very light skim and be able to leave the same brushes in it.
as a point of comparison at the hobby staion inviational i ran a 9×1 4mm motor which after 3 runs needed 2 passes on the lathe and a new set of brushes.
i’m keen to test with 4 cells at other tracks (brendale, wynnum, etc). will be interesting to see how they compare on longer tracks.LikeLike
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As I understand it, in Japan where most of the 4 cell racing has been happening they are still blowing up motors etc because they are using 4 and 5 turn motors. In other words nothing has changed. To make the change to 4 cell achieve the goal it might be necessary to limit the winds to a lower limit of 7 or 8 turn.
Just my 2 cents worth I am not a modified driver. Be interesting to see the brushless with 4 cell as well.LikeLike
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Not sure about that. I didn’t think they had actually run much 4-cell yet, but just begun some testing. Lots of “who knows” about. I think Anthony is one of very few who have actually tested some stuff!
I’ll try and run a 4-cell pack with the Novak GTB/4.5 next time I’m at a club race.LikeLike
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I have to agree with Heavy. There is still ample run time available with current cells (4200’s) so after you drop a few cells, you can regain that loss by bolting in a lower-turn motor. Which brings back all the associated problems.
If you ran the current cells with a 9 turn motor there’d be no problems – so the issue is actually that the enormous run time allows drivers to run 6 and 7 turn motors with plenty of timing. This is causing super high amp loads and heat, leading to motor or esc failure.
If we had less capacity (ie 3300’s max) you couldn’t run 7 turns with high timing. Of course it’s too late now because all the new cells have been approved.
I’ve read that you can’t slow down the cell makers development, because they are primarily catering to the power-tool market. I wonder how true this is? I’d like to see just what IB and GP sales are like for power-tool cells. My understanding is that many power-tools have moved away from nimh cells. Anyone have any knowledge about this?LikeLike
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I don’t disagree, it’s just that anytime you cut capacity you reintroduce the “run-time” wars of the past. That’s the one great thing about todays cells. In fact, thinking about that, its not the capacity that’s the issue, it’s the voltage. 4200 cells would be no problem if there were 1.15 volts. It’s the fact that they’re getting up around the 1.24 volts.
If I was making the decisions I would be seriously considering 2wd (rear wheels, not front – there’s no such thing as a “real” front wheel drive race car!). Sure 2wd would be harder to drive, but tourers are so over-gripped it’s not funny!
I wonder if there is a tech solution – a voltage regulator set at 6 volts (or 6.5 or whatever works), then let capacity run wild….LikeLike
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Lithium Ion/Polymer, now there’s a whole new problem. Most power tools are tending to go this way due to the power and time of use. Mobile phones went to lythium technology over ten years ago.
Once the lithium batteries are made available what is going to to stop people running 2 turn or maybe even 1 turn as Im sure the companies will develop them. This means that we end up still having the same problems as we are now.
I dont run mod because I cant afford too but I have a suggestion to through in the ring, the mod drivers may find it useful or not, anything helps right.
Why dont you try limiting the turns of the motors for modified racing at least at a club level regardless of run times, grip, battery technology. Limit it to say 8 x 1 or 9 x 1. This way there will be less failures, plenty of run time and maybe even the chance to run up to 10 min finals so that the electric guy’s can have something bigger to look forward to in the finals as the gas guy’s do. it will also provide for better raacing as drivers wont be concerned with run time, it will come down to set up and driver asbility. The class will grow and then the racing gets much better equalling more fun.
This will make it yet another (restricted) class, by that I mean you everyone will be running the same motor to a degree but it will develop the lesser driver in this class better and will make the class more appealing due to a major drop in costs.
Then if needed each club could run a “open” class where if you have the money etc you can go at it with whatever you want. This will allow LHS’s to do product development and those that can afford it can try new things and this way we continue do develop the sport but not at such a high cost. As for major titles I guess you have to go by the governing bodies rules but that will only be one weekend every blue moon. If this works they may change to aloow the same.
Just a thought……………LikeLike
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imho going to 4 cell mod is the best option, and would probably see myself and others moving up to modified racing. as it is 6 cell mod is just too fast and a huge step above stock racing, and car wear, tire wear and other factors are increased ten fold. bridging classes such as 19t haven’t really taken off and until they do, or the speed of modified is reduced, i can see most people remaining in stock…
limiting cell capacity will just mean new cells again for every meet to make runtime or be competitive, and is a major step backwards and another expense. it will also impact other classes such as stock where the new high capacity/voltage cells have added to the racing experience.LikeLike
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under 7 turns, each turn less has a massive drop in efficiency as you get closer and closer to basically creating a straight short. if 4 cell alone is not enough, a small increase in race time (6 – 8 minutes) in conjunction with moving to 4 cells would certainly stop such motors being run untill there is a very significant increase in capacity. in the testing at hs i ran whole packs till they dumped with no fear of burning the motor up, something i nolonger dare do with 6 cell packs.
japan tried running extended racing (8 minutes) on 6 cells but the voltage has just got too high for this to work as even ‘conservative’ motors are really burning up these days on 6 cells.
i for one am extremely eager to see what comes out of this years jmrca expert touring championship (japan’s mod tc nationals) as they have already made the move to 4 cells, reduced car weight to 1350g (including timing equipment) and will run 5 minute races.
i strongly believe having only 3 classes of touring car is the way forward.
4 cell mod (expert), 4 cell 19 turn (intermediate) and 4 cell 27 turn + 6 cell 540 as the novice class. making it not only easier for people to get into (and stay into) the hobby but also to progress up to the top level if their skill, rather than their budget allows.
modified is certainly hurting the most but i believe the other classes too would benifit from such changes. it’s frustrating to see stock drivers changing motors and/or truing comms at club meets. just lately i’ve seen a few interested people have their enthusiasum killed off when they’ve seen the sheer amount of equipment and work going on in the pits. wouldn’t it be great to be able to leave motor masters and comm lathes on the pit bench at home for all but the biggest race meets.
i’m fearful that the way things are, a long hot summer could be an extremely big blow for modified racing in brisbane…LikeLike
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somehting i forgot to add to my inital report from testing 4 cells at hobby station.
i didn’t run a reciver pack. with an amb personal transponder no laps were missed. also no difficulties were experience with the servo.
equipment used – ko vfs-1 comp esc, ko 302f receiver, ko 2413 servo.LikeLike
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i think 4 cell mod is the only real way to go, and like Anthony, i’m awaiting some good reports from JRMCA races to come through, hopefully quickly enough to carry on the current momentum of discussion and actually get somethign done about it.
with regards to the other alternatives, 6-8 minute mod races would be good, but at 6 cells all it’s going to do is increase the amount of heat & power forced into the current motors, and imho, they simply cant take it anymore. i think some testing on 4 cells is needed first, then maybe up the runtime, although as Scott pointed out, if we just crank up the runtime then we’re going to go back to runtime wars again.
while i’m all for 2wd racing, there’s already a class for it – 12th scale 🙂 i’ve heard of guys overseas (mostly europe) running pro10 still on 6 cells, and the things are just ballistic with the current batch of cells, and thats with a proper bodyshell (ie not a sedan)… i dont think i’d like to try and control a 2wd touring car at those kinds of speeds!
I tested 5 cells at the start of the year at templestowe, it wasnt that much slower (considering i never changed gearing or timing), i also tried 4 cells which was noticeably slower (mind you once again i never changed gearing)… i’m keen to get out there again some time soon and try with 4 cells and see what i can do.
I dont think that going to 4 & 5 turn motors will work with 4 cells, i think a 7 or 8 with high timing, or even 4mm arms would be the way to go… much less loss of efficiency than compared with a drop in winds, yet still a fair increase in power. a 7×2 4mm would be a nice arm on a large trackLikeLike
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i have skim read what u all said and imo 4 cell would be good except in classes below mod i feel 4 cells will make stock and possibly 19t feel a bitto slow but i am still new and only run 540 but this is how i see it
i think itd be great cause i my self would like to one day run 1/12th and having 4 cell touring packs would help id have just one set not 2.
as far a limiting the number of turns why cant we do it now say for nats and stuff a 9t limit? should putesc under to much strain but yes the motors will stil be pushed so it is a band aid.
on a larger scale though whatabout the international level ie will this make australian electric drivers less skilled? although ihavnt seen an ausy win the worlds u still want to give everyone a chance and running 4 cell while every one else is runing 6 could disadvantage up and comming drivers o the world scale.
what are your opinions on that??
but as a whole 4 cell mod just mod sounds great
just my $.02LikeLike
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While we are running a mix of brushed and brushless motors limiting motor winds is not the answer.
4 cell is being considered on teh International level and discussed widely – not just in Brisbane.LikeLike
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the other reason you cant run a limit on winds is because %$#@ like me will get some rather ‘special’ 9 turn motors which perform closer to 7s & 6s 🙂
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while testing 4 cell 19 turn is still on my todo list before i can say anything for sure about how it compares, i have a feeling it will be similar to 6 cell stock (27 turn) but should have quite a bit less motor wear.
4 cell modified is faster than 6 cell 19 turn but with alot less motor wear. the slightly curbed speed and greatly reduced costs will make modified alot more accessible.
which should mean that if 4 cell 19t doesnt satisfy the top stock guys it should be alot easier for them to step up to the premiere class.
the way it stands at the moment… it seems more likely for top drivers to drop back to stock than it is stock drivers to step upto mod simply because of the growing costs involved as the cells improve.
motor limits haven’t worked in europe (12 turn) nor usa (10 turn) as all the excess runtime leaves alot of energy to burn motors up by over gearing and running alot of timing.
increased race length (8 minutes) might have worked for a year or so in japan but at their last nationals it was clear that the cells had just got too big for this to be the solution. earlier this year they became the first governing body to make the move to 4 cell modified (5 min). japan’s modified nationals (toughest and most exclusive nationals in the world) will be run in november at yatabe arena.
this might work out well as our nationals are also in november and im guessing most mod guys will want as much 6 cell practice as they can get leading into them.
after the nationals might be the ideal time to trial a change as alot of people will probably be a bit burnt out from the cost involved with such an event… with a long, hot summer ahead would make 4 cell an attractive change.LikeLike
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All we need then is for a club to put there hand up to run 4 cell modified for say the Dec to March period as a trial – would only be viable for a club to do it if there were 6 or 8 guys willing to trial it over a period
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There is also some discussion on this matter being generated on teh AARCMCC thread on rctech to check out
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Looks like we will have one and probably two more touring car meets at Hobby Station before it goes to Offroad – do you guys want to run a 4 cell mod class at those two meets to give more people a chance to do trials.
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Put my name on the list heavy. I will give it a go.
Anthony…..Seeing you have done a little testing already, can you give me a starting point with timing and ratios please. Will run an 8-9 turn.LikeLike
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I’m also interested in running 4 cell mod, put me down also
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the following should be a pretty good starting point for hobbystation
7 turn – 18° – 9.5 FDR
8 turn – 18° – 9.0 FDR
9 turn – 18, maybe 24° – 8.5 FDRLikeLike
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