More rubbish
Mardave class was allways 4 cell nicad,nimh before it went to gt. Not 6 cell which would be 2s.

I did a 2 day national on one 1s cell, no performance change. Full entries of 1s cars at nationals shows 1s is the class...

go down the fusion exceed route £80 motor speed control combo buggy saddle packs 2 for the price of one 1s buy a fast servo off ebay job done works without a booster if it all goes ti-s up can buy a buggy for less than a gt12 and have some fun in the dirt without all this politics stuff i did and dont miss it at all all this petty rambling is taking the fun out of gt12 pick a system and someone will try and introduce a "better"one usualy someone who has deep pocket and little talent and uses deep pockets to win run what you want but make sure everyone runs the same try not to mix 1s and 2s it will end in tears

You seem to be miss in formed, there are a clear set of rules for nationals, 1s 13.5 only, clubs may use 2s 21.5 at the clubs disgretion. 1s is here to stay.

The rules are set for gt class in April when the 12th section has its agm. Ie end of the 12th season.

To check a Speedo is in blinky mode you need to compare it to the list.

Do you know how to check your motor is in 0 timing without using the marks, there is a way

Its all very well to say a club can do what it likes but in reality this is a bad thing, as we found out to our cost… People get a great boost by racing in a National event you get too see much more and really get a chance to spread out but if you do not follow the BRCA rule book then this is out of the question.. you then end up with those with money or who are sponsored who can and those who have to go it alone who can't..

I do not believe this should be the way of the GT12 class

You want to go pro go 12th or TC lets not be so tight on the GT12 otherwise there is no where for the young guns to start

So remove all that and everyone knows what to buy, job done....

Quote:

Originally Posted by mark christopher (Post 719012) So remove all that and everyone knows what to buy, job done....

I think not... Please show me where in the Rules (Link below) that it states that 21.5 is for club only??

http://www.brca.org/index.php?q=sect...12-rules/13572

But what about the people that have already gone the 2s route!

Also from what i have seen 4 cell is a million mile away from 1s/13.5 so it should not be in the rules also then!

Steady Tigers!

1S systems do not put more stress on the motors than any other system. Whilst they have a higher current draw they have much lower revs. If you over-gear any motor on any system you will wreck it. On 2S, the motors rev higher putting higher mechanical strain on the parts. If you run 1S you put a higher electrical load on the motor. It's a trade of one set of strains on the motor for another. In both systems if you do not correctly gear a motor you will harm the rotor, but we have never, ever had a rotor explode on 1S whereas it has happened in 2S. I've never had a bearing replaced in a motor on 1S, but plenty were replaced at the Worlds on 2S. Different systems, different strains, different results, both able to toast a motor if incorrectly geared.

As for the cells you may think what you like but the facts are against you. Any 1S pack on the BRCA list will last you 200+ races or more even in a 12th Modified car before you could even call it tired. At club it will go even longer. Interestingly, the biggest growing electric classes in the last five years are the 1S classes - 12th, GT10, GT12 and F1 - in all corners of the world. If 1S was a cell-killer it would have got nowhere. You are entitled to your opinion, but for everyone else your summary does not reflect the facts.

Roger, I am sorry you find the Rules confusing. Here's it in a nutshell:

For National racing we run 13.5BL with 1S cells. For anyone organising meetings outside Nationals we have put in details of G2/4-cell and 21.5/2S to use.

The G2/4-cell needs no further clarification. For the 21.5/2S we gave guidance in two areas - a list of motors locked on timing so performance is closer, and using 'micro' 2S cells for which there is no BRCA list.

A car must be supplied as a rolling chassis, with wheels and tyres for £100. Whatever chassis comes with that car is what you use. If you want to modify the car and use a diff it races in GT12.1. If you just want to tune springs, dampers, etc. and run without a diff you can run on GT12.2.

Taking your point, I will make sure that such a summary is available on the BRCA website for 2013. I take issue with the 'mess' description as you are the only person to mention that since we started. I have had a lot of questions, but no one prepared to travel as far as you to avoid the class!! I'll try to make this a non-issue for you with the 2013 rules as I am mindful that you might be saying what others are only thinking! :)

To clear the rest up - we will have something on 2S classes more easily discoverable in the rules, and we will not be doing any more on bodies than presently in the Rules. Reverse can be discussed only if someone puts a proposal up for it, and the 2013/14 rules will be published next April after the EGM in early April.

If there's anything else, please come back an ask. It would be great if we could please all the people all the time, but we are realists! nonetheless, as I have said before, your feedback is appreciated and valuable. Please be part of any changes - things suggested on here will not make it into the Rules unless they are proposed at the EGM, discussed and voted on. Play your part to shape your class! :)

That is the problem Mark, I'mmmissing informed, little Johnny who wants to start racing is alsommisinformed & his dad thinks "stuff this, a play station is easier" & yet another junior racer is lost forever.
Mardave's have always been a great place to start racing... until now it seem . :-(

I use a core 45 esc on 1s using half saddles from my buggy, my 13.5 bl motor comes off track only luke warm, as the esc can only draw an average 45 amps whereas my 2wd buggy has a 150 amp esc on 2s which means its drawing 3x as much and twice the voltage.. :eh?:
....................

Sorry man but 4 cell NiMh does not equal 1S LiPo. There is a +30% nominal voltage difference (4.8V/3.7V), which is the cause of the problems on 1 cell systems. The voltage difference between 6 cell NiMh and 2S is nominally only +3% which isn't a problem at all. The huge current and therefore significant voltage sag seen in 1S only compounds the problem, as Mardaves ran low power motors that never asked much of the 4 cell NiCds this issue never arose there.

These issues will not kill the class, it is too much fun to race for that. But you'll end up with a fixed elite doing Nationals with much less penetration from club racers wishing to give it a go. None of us have the full picture on what systems are used nationwide in GT12 clubs, but for sure there are many, many people using 2 cell LiPos.

Thats why it always best for little johnny and his dad to visit local clubs to find out some information and be guided to the right path.. but they may still go away and come with something entilely different from what you suggested..
mardaves are still a good place to start and most likely would have been 4cell - which as we all know is 1s..... :D
or Oval stock car/hot rod 6cell - 2s

little jonny goes to his local modelshop and ask what have you got not many will say mardave as for cost a 1/10 buggy ready to run is less than a mardave kit and can be run anywhere gt12 is now a racers class not a beginners

thats why 1s is for bl and 4cell g2.. 4cell powering a 13.5 bl is stupid quick.. TBH im glad i dont use cells anymore (all that charging and discharging got on my tits, havent the time) - lipos are brilliant :D
..............

i honestly havent spent a fortune on buying top gear, core esc, half saddles, dynamite 13.5 bl was even using a rtr servo up untill i crashed, so now have savox 1357.. 40 megs radio and pt ive had for 4-5yrs... im just an average driver, most of the stuff ive got is second hand :cry::lol:
but i will be racing at the tamworth national on sunday, just for the experiance of doing so and no doubt i'll be in the bottom final. :lol:

also hotrods for 2013 are 1s, so are stockcars if running bl!!

exactly its not clear as the "club guide lines" are in the rules as an a apendix.

21.5 is NOT a national class

try reading the entry form, i have posted this before and Look at section 7 of the rules

http://www.brca.org/index.php?q=cont...onbridge/17800


Class Rules
13.5T brushless motors as per Electric Board list.powered by a 1S LiPo cell on Electric Board list. Approved ESC in “blinky” mode as per Electric Board list
Or
G2 brushed motor powered by 4 cell NiMh

NB 21.5/2S combination is NOT allowed at National level

easy, keep running it at thier club at club level and buy 1s if they wish to go to a national...

it still is, you just need to make sure you have the correct info, as i did, i emailed the 12th officials who were more than willing to ensure i got the correct facts in my head, the reason i "seem to know" about this subject is because i took time to find out and spent time chatting to pete winton (slow one)

cheers pete did not want to start pointing him towards the correct lipo/motor facts too, knew you would get here in the end:thumbsup:

im not sure where you are getting your "workings" from but your way out...

for example the core 1s system is a 45 amp speedo, now that means it can only pass 45 amps from the lipo to the motor, and the motor is not drawing enough to pop speedo's

i get the feeling your just anti 1s

what 2s lipo do you use and from what class did your gear come from prior to gt?

so why are clubs thriving and gt class is the biggest grower indoors?

Well put points, but electrical loads affect the whole car (motor, ESC, battery), whereas mechanicals only affect the motor. So I stand by my opinion that 1S puts higher loads on the car's power system. I'm currently making a finned aluminium pod floor for a GT10 car to get rid of more heat for this very reason - to allow bigger gearing in 1S without blowing up the motor. I never said 1S would be a cell-killer, or motor-killer. But it WILL load these components to a higher level.

well i disagree with your opinion then

Mark, we do disagree, I have stated my opinions so we can leave it at that. This is something we do agree on!

My workings come from this:
1S and 2S cars lap a track at a similar pace. They therefore are producing similar power levels. 1S car does so at half the supply voltage, so must draw about twice the current to achieve this. Resistive losses scale as the square of the current, this is where the extra heat comes from. Your 45A speedo will not restrict the current flow to 45A. It might just overheat if the continuous draw exceeds this value though. Instantaneous spikes of somewhat over 100A are very likely. Modern cells can take this, but of course the 1S system NEEDS to be heavily loaded up (geared) to get any performance out of it so it isn't doing the battery any favours. In an era where people are so conscious of battery safety, this appears to be a strange move.

I use Loong-Max 2300 2S batteries in a solid machined case that I manufacture and sell. Prior to GT12 I raced touring, before that I raced GT10 (as a 2 cell). I also race off road 2wd occasionally and have 1/10 SC truck and several nitros. I have been involved in RC for 15 years and been manufacturing components for 5 years. I had one of the first brushless drive systems for RC cars in the UK in January 2000.
I am indeed strongly anti 1S. That's my history, cheers.

DAVE

But i cant, if you remove the 21.5 / 2s from the club guide lines / rules the club will not let me run, and i will have to spend £150 / 180 to carry on running at the club......

The club is only going to run the brca rules to the letter. No mention of 21.5 = a big waste of my money and having to spend more....

I guess you could slap your stuff on Ebay immediately before anyone realises it isn't legal and buy some 1 cell stuff...

personnally i think that would be a bad move for your club, upsetting a lot of members :thumbdown:

btw if your using saddles, they are legal to use, the servo u have may be okay too, so its a new esc & motor which could be got for £100 or less..
your esc may handle 1s ? you never know...

Interesting discussions but I'm not sure anyone has considered the motor wind in the calculations.

For "compable speeds" assuming similar gearing a 21.5T motor is wizzing around at about 60% more RPM that the 13.5. This generates more heat and surely draws more current?

Clubs can do what they want
 

I am a little confused by this statement. The 21.5 class being redundant is not my experience at a number of clubs locally, far from it in fact. Whilst it may be the case at national events, it may not necessarily reflect the national club scene. There does not appear to have been any caveat in rules that stated 21.5 would be removed if not taken up at national events.

I find it reassuring that clubs adopt BRCA National rules for the classes they run locally and assumed that the BRCA considered this point when setting (or amending) class rules.

IMO removing this particular section would devalue its currently popular following at a number of club run events and championships. It may even damage what is a growing class that is encouraging new and returning racers.

The general theme of removing previous rule guides, especially recently published items such as this, may also devalue future rules set by the BRCA and I fear, goes against a number of the associations core objectives.

Paul

Paul - couldn't agree more.

Dave:

If the speeds and gearing are similar, then the motor RPM must be also. The calculations bear this out, using typical motor values:

13.5 motor @ 3300kv, at 3.7V = 12210 RPM
21.5 motor @ 1600kv, at 7.4V = 11840 RPM

So the motors indeed rev to similar speeds. However current draw has nothing to do with RPM in a motor, only torque. While all motors have an RPM/V coeffient known as kv, they also have a torque per amp coefficient called kT which is rarely discussed.

spot on dave....

Ah it makes sence

well i have no "interest" in what class im pushing, my lipo sponsor can supply me 1s or 2s stubby
i have racer elec TC, buggy,f1,12th and sc, 8th off road ic, 10th, 8th off road ic, won nationals and been racing/involded in rc for 30 years. i was one of the first to use lipo power in 4x4 buggies (pre production soft case trackpower) been an active brca section comittee member and a scribe for a uk mag for many years, i believe in the best package for the best classes, giving the racer the best fun. oh and i read rules fully...
thats my history, cheers. :rolleyes:

thats an issue your club needs to decide, the rules they are following are guide lines only...

just have national rules, i fail to see your point, the elec off road section do not publish different rules for clubs to use, nor do many other sections, clubs simply follow the sections brca rules unless they decide not too

As has been pointed out several times above, what your club decides to do is entirely down to the club and has nothing to do with the BRCA rules. If your club want to run 2S then there is no one stopping them doing so, there isn't going to be anyone from the BRCA committee coming down to check what rules you are running to as the BRCA has no control over what clubs do.

If you are unhappy with what your club is going to do, the people to speak to are your own club members and committee, complaining on here or to the BRCA committee isn't going to make any difference to what your club does.
If there is a group of you who are currently running 2S and want to keep running them then the club must be pretty stupid if they could be turning away current members purely because they aren't capable of managing their own rules and have to adopt what the BRCA run. If everyone else at the club is happy to move to 1S only, then whether the BRCA includes 2S rules in an appendix or not isn't going to make any difference to stopping your club moving to 1S only.

Am I missing something here? Surely the simple way to find out what you need to run at your local club is to go down there and ask them what they run. Why are you making a 100 mile round trip to avoid them because you don't know what rules they run to? The BRCA rules might have no bearing on what they run, the only way to find out what classes they run is to go and ask them.

The BRCA rules for sanctioned national meetings have always been for 1S 13.5. The rules have also always stated the 21.5T appendix was there as a framework for clubs if they want to run 2S.

I was led to believe that the BRCA set class rules and guidelines to promote the sport and encourage competition. I therefore questioned how removing a previously published guide that had, in part, contributed to the formation of what is becoming a popular class, achieves this.
Paul

Little Johnny who wants to start racing will only be misinformed if he is misinformed by his local club.

No one I have ever known in all my years running a club has decided to start racing and first found out about the BRCA and then bought all his equipment based on the rules for the class he fancies having a go at. Every new racer I have ever known has started by going to his local club and asking questions, and any decent club will tell them what the basics are they need to get them going, not what they must buy to be competitive.

As for new racers buying equipment that isn't BRCA legal, I would say at least 90% of brand new racers will have illegal equipment. RTR touring cars and buggies come with Mabuchi 540 motors, first brushless systems being Hobbywing sensorless systems - cheap but not BRCA legal. Cheap nimh cells that came with the car, again not BRCA legal.
Any decent club shouldn't care what electrics are in a beginners car, the whole point is just to get them started and take things from there.

No class has ever died out or been avoided because the body wasn't scale. Pro10 did not die out because of the bodies used, nor did 1/12th numbers drop because of the non scale bodies. If you believe that why did 1/12th pick up again with even less scale bodies. The people who say touring cars are boring would still see it as boring if they had accurate scale bodies as they would then be running with slower motors.

There is a reason there were heat after heat of Stratus and Mazda 6, those were the bodies that worked best. Look at WorldGT, there is a body list of around 20 bodies of various makes, yet everyone uses the Protoform Sophia because that handles the best. That's why you see everyone running an Ascari.

If you want to open the body rules at national level then do what everyone else does and put in a proposal for the AGM, complaining about it on forums isn't going to change the rules. If the majority of racers vote for an open rule then you can run what you want, although it's highly likely you would then end up with a class of GT racers being full of Mazdaspeeds.