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Old 03-10-2016, 07:27 AM
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Default 1/12th 2 Cell Racing

12th stock racing in Japan is unique. Some race are 1 cell others are 2 cell, like as US rule.

In those, I felt 2 cell racing is low cost because 2 cell battery is very low price in Japanese market.
Street Price
Yokomo 1600mA 10$/pack, 85g
Orion 1600mA 16$, 105g
Torion 1600mA? 25$, ?g

1cell 13.5 and 2cell 25.5.
These two car is just same speed and lap on the 730g rule.

1cell 17.5 and 2cell 30.5
2 cell 30.5(Yokomo motor) are same as current 1 cell 17.5. I think from 33.5 to 35.5 prefer for 2 cell stock racing.


1. 2 cell 12h racing is low cost as well as no required voltage booster.
2. This can allow to share motor and battery with F1 rubber class.
3. Easy battery management on charge because when 2 cell charge, most charger use voltage sensor lead. 1 cell(1S2P) battery can not manage cell balance.

2 cell 21.5, current Japanese role, is over speed. JMRCA national TQ in stock class is the same lap as A final 10th person on open class.

I think US 17.5 class grows faster than 27.5 with brush motor. It maybe 21.5 prefer. However, it is 1 cell. 2 cell racing market a wide variety of choice ESC. In addition, almost all of them are cheaper than ESC with booster.

How do you think about 2 cell 12th?

This car is for no regulated weight race in Tokyo last year.
Car is below 600g with Yokomo battery.

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Old 03-10-2016, 10:30 AM
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Originally Posted by landau View Post
2. This can allow to share motor and battery with F1 rubber class.
I don't run F1 so this reason doesn't appeal to me.

Originally Posted by landau View Post
3. Easy battery management on charge because when 2 cell charge, most charger use voltage sensor lead. 1 cell(1S2P) battery can not manage cell balance.
You can't balance a 1 cell because the balancing function is to make multiple cells the same within a single pack. A 1 cell is always balanced 100% of the time. Inline vs parallel....same on a 2S2P.

Originally Posted by landau View Post
How do you think about 2 cell 12th?
We don't need another class...

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Old 03-10-2016, 11:10 AM
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1s batteries are typically 1s2p so its pretty rare to get a perfectly matched pair of cells and one goes puffy before the other ect.
2s packs properly balanced and not abused should last longer but in the case of modern high capacity 2s2p you have the same problem.

Doesnt really make things easier but i guess you could share batteries between classes if you had to.
But no more classes please. Waaaaay too much dilution. Ahould be a stock and a mod 1:12. 1:12 isnt even a beginner class really. Run f1 for slow noob class then take up tc or 1:12.
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Old 03-10-2016, 11:44 AM
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Originally Posted by valk View Post
Run f1 for slow noob class then take up tc or 1:12.
Spit out my chocolate milk lol!
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Old 03-10-2016, 01:53 PM
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I can see from the description that you're trying to compare competitive times between 1 and 2S with different motors and attempting to find parity. What you will run into is that even if you can find parity between them, it will be hard for the established class to legitimize both equipment types running together. There will always be a perceived advantage one way or the other. As stated, there are already at least 3 levels of 12th in the US and 12th scale is a hard sell to begin with. I personally don't object and if it works in your corner of the globe, have fun with it.
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Old 03-10-2016, 01:57 PM
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Originally Posted by valk View Post
Run f1 for slow noob class then take up tc or 1:12.
You'd be surprised how many people put an F1 down and can't keep it off the pipes. But, I agree with you on 12th: Stock and Mod.
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Old 03-10-2016, 04:31 PM
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I race 2s 1/12th 21.5 here in Japan, and it's not cheap. That is, to be competitive, you need top quality equipment and you need an aftermarket power capacitor. Like the $50 Cavalier power capacitor by Acuvance.
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Old 03-10-2016, 07:55 PM
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What does the capacitor do? Thanks
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Old 03-10-2016, 08:03 PM
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2 cell racing has some benefits and 1 cell has detriments.
I cast above 2 cel benefits. Here I state detriments of 1 cell.
But I well know not only 1 cell has benefit but also I agree with no more category.

1. miss charge

This year JMRCA race separated 1 cell open and 2 cell stock 21.5.
Before then allowed to run both class. This is same as local track race.
In the case, I watched sometimes Lipo battery explosion because racer charged 1 cell battery by 2 cell setting. This was not once.

Recent race have a wide variety of category including 1 cell and 2 cell on a day. But racers may use same charger by cell setting every times. When you attend 2 category Q3F1 race, it requires seven times changes. If it forget once, what happen? Most cases will find out before explosion. But rare case is not.

Racer who use same charger or if 2 cell only allowed, will prevent from those mistake.


2. balancing

As you know, most 1 cell battery for 12th is 1S2P. Each cell lie on above and below in battery case. Racer use always it same direction because battery terminal is one side. Therefore, each cell dose not equal to get worse by heat problem. Upper cell cooling by air during run, but other cell sandwiched by between upper cell and carbon chassis. This effect gets damage cell. I have dismantled 1 cell battery over 10 packs so far and check each cell balance. Without exception, though not many sample, below cell had damaged.
If 1 cell is made of 1 Pack, cell balance is not problem.


How do you think again?
Thank you for your opinion.
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Old 03-10-2016, 08:26 PM
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Originally Posted by ixlr8nz View Post
What does the capacitor do? Thanks
Magical unicorns will shoot out of your motor
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Old 03-10-2016, 10:37 PM
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landau,

It's great you prefer running 1/12 on 2s. I also prefer it, and enjoy its many advantages, especially the shorter charging time. Sadly here in the US 1s 1/12 scale is here to stay, and has little chance of ever changing.

The main arguments you'll hear are, 1s 1/12 racers have already made large investments into 1s equipment, and many only run 1/12 so have no need for anything else.

You'll also find that the modern US 1/12 racer prefers an extremely under powered car, as it forces you to buy a new motor & batteries every 6-months to remain competitive, and provides the additional enjoyment of watching a 4-door sedan drive away from you on the straights.

If it was up to me 1/12 would be setup into the following 3 classes:
Sportsman: 2s, 21.5, Blinky Esc, Spec Tire (Compound TBD), No Sponsored Drivers Allowed
Super Stock: 2s, 21.5, Open Esc, OpenTire
Modified: 1s or 2s, Open Motor, Open Esc, Open Tire

At the club level I'd offer Sportsman & Super Stock, and for BIG races would include Modified.

One day 1/12 racers may wake up and ask, "why are we running on 1s when practically EVERY other RC car (on-road & off-road) uses a 2s battery?" But for now, US 1/12 scale racing is 1s and the masses aim to keep it that way.
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Old 03-11-2016, 04:56 AM
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Originally Posted by AZ Wolfie View Post
The main arguments you'll hear are, 1s 1/12 racers have already made large investments into 1s equipment, and many only run 1/12 so have no need for anything else.
And this is a valid argument.

Originally Posted by AZ Wolfie View Post
You'll also find that the modern US 1/12 racer prefers an extremely under powered car, as it forces you to buy a new motor & batteries every 6-months to remain competitive
And going to 2S won't change this need to buy new batteries and motors every 6 months.

Originally Posted by AZ Wolfie View Post
If it was up to me 1/12 would be setup into the following 3 classes:
Sportsman: 2s, 21.5, Blinky Esc, Spec Tire (Compound TBD), No Sponsored Drivers Allowed
Super Stock: 2s, 21.5, Open Esc, OpenTire
Modified: 1s or 2s, Open Motor, Open Esc, Open Tire
12th scale should be 2 classes. Stock and mod. That's how it started and that's how it should always be. It isn't a beginner class. It never was intended to be that way and no reason to water it down to make it one.

Keep in mind that back in the 80s, 90s and early 2000s 12th scale ran 4 cell while everything else ran 6 cell. Running less cells is nothing new.

Originally Posted by AZ Wolfie View Post
One day 1/12 racers may wake up and ask, "why are we running on 1s when practically EVERY other RC car (on-road & off-road) uses a 2s battery?" But for now, US 1/12 scale racing is 1s and the masses aim to keep it that way.
We will when all carpet oval racers wake up and say the same thing.

In the end the only valid argument is to standardize battery cell count. All the other perceived advantages of 2S over 1S are subjective and it ends up being a wash.
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Old 03-11-2016, 05:19 AM
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Originally Posted by EDWARD2003 View Post
Magical unicorns will shoot out of your motor
Omg I'm ordering one right away ! Can't wait
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Old 03-11-2016, 08:33 AM
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Originally Posted by AZ Wolfie View Post
One day 1/12 racers may wake up and ask, "why are we running on 1s when practically EVERY other RC car (on-road & off-road) uses a 2s battery?" But for now, US 1/12 scale racing is 1s and the masses aim to keep it that way.
one could have asked that when 12th scale was running 4 nmh cells and other cars all ran 6. 12th once ran 6, but as motors became faster 6 cells was no longer needed. some used to falsely say that 4 cells was just as fast as 6, that is not true. i site this example.....at the 2003 EFRA 1/12 championship race they allowed 6 cells with a 17T bushing spec motor vs 4 cells no motor limit. this was supposed to even the 4-6 cells out, it didn't. EU still had a lot of good 6-cell driver holdouts. after first qualifiers there was a huge protest, pro 4-cell drivers (names we know even today and still race) confronting officials over the 4 vs 6 cells. summary:

- 4 cells where slightly faster in the infield, resulting in different lines thru the infield vs 6.
- 6 cells were insanely fast, to the point they negated the 4 cell infield advantage. 4 cell car spends 2-4 laps working a clean pass, boom negated next major straightaway
- 6 cells were heavier to the point that if a 4 cell and a 6 cell barely touched, the 4 cell car reacted like it was hit by a mac truck
- EFRA caved under PRO-driver pressure, they split 4 and 6, reset up heats
- many pro factory sponsored drivers would have not made the A main, relatively unknown 6-cell driver was qual'd second
- at the end only the 4 cells got worldwide posts on results, equip used, etc
- 6-cell winners in a photo, treated as a by-the-way also ran class

1/10 pan oval [/B]had a huge resistance going to 4 cells, i saw races where 6-cell classes ran into 2006. when the lipos were starting to be allowed into RC car racing, 2s was deemed to fast in pan oval especially with a 13.5 which was way faster than any 27T and 19T brushed motor. that when the oval racers started asking for 17.5 motors and it was still too fast with 2s. they went 1s problem was fixed.

i was still racing 12th at the time, most of us went BL but stayed with 4 cell nmh till lipo batteries were sorted out, we then started using 1s lipos like 1/10 pan oval racers were using

17.5 are now faster than 13.5 of 10 years ago, using a higher voltage super slim 2s shorty in a 1/12th with a 21.5 imo would not make a difference. maybe with a 25.5, but it wouldn't take long for for a 25.5 - 2s to be faster than a 17.5 - 1s

Last edited by fast-ho-cars; 03-11-2016 at 11:15 AM.
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Old 03-11-2016, 09:24 AM
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Originally Posted by Drew Manzella View Post
Keep in mind that back in the 80s, 90s and early 2000s 12th scale ran 4 cell while everything else ran 6 cell. Running less cells is nothing new.
.
1/12 scale

in the 80's used 6 cells outdoors, 4 or 6 indoors based on track size, but 6 was dominant

in the 90's, 6 cells were still being used in US indoors and outdoors.

1990 at ROAR level 1/12 scale was run as 2 classes, 4 and 6 cell mod

1994 IFMAR 1/12 worlds run indoor carpet, carefully watch beginning 6 cells. https://www.youtube.com/watch?v=FsKENSGBG-k

1996 iIFMAR https://www.youtube.com/watch?v=X4WPnYJs4XA watch carefully till you get to Cliff Lett, he has 6 cells hard to tell with black shrink wrap, but when the camera pans out, briefly left there is another car with 6 cells in the corner

in the 2000's while not in the US, you see my post above about 2004 EFRA run indoors with some using 6 cells.

2004 AE released RC12l4, no longer has 6 cell slots

Last edited by fast-ho-cars; 03-11-2016 at 10:05 AM.
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