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Old 01-24-2006, 11:42 PM   #61
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Lots of good points in here. I like the story about the Boeing employee who obviously didn't catch the fact that scale models don't speed through scaled down air. As for the ME & EE mistakes, I agree are indeed mistaken assumptions that get them labeled as misguided know-it-alls.

While I'm not a practicing ME, I do have the degree. I also keep my eyes open! There's a concept. So to anyone who thinks more cells equals more runtime, go run 1/12 mod with more and less cells as an experiment, and be sure to keep your eyes on the lap times. The math will lie to you b'c the assumptions aren't based on the reality of our exercise in miniature madness.

It'll be interesting to see where this goes, even though I'm all for more power! Maybe it's time for me run those smelly gas cars?
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Old 01-24-2006, 11:51 PM   #62
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Quote:
Originally Posted by rangulo
I was just talking about the high impact of a crash.. Some of the guys who race gas have them for their receiver packs and when they crash...PISSPISSSPISSSPISSPISSS....Thats what they sound like... Melts there plastic holders.. THey are great advantage seeing how they weigh 60 grams less then a standard nitro receiver pack....
The rx packs being used are pretty old tech. The new LiPo packs from Kokam and Orion are of a new refined chemistry. I would not suggest you do this but I have heard that you can hit them with a hammer, drill a hole through them, chew them up with a bench grinder, etc and you get no fire, no drama, just a ruined battery.

Like I said...they only way to get them to burn is to grossly overcharge them with the wrong type of charger, faulty charger, etc.
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Old 01-25-2006, 12:11 AM   #63
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Instead of going to 4 cells it might be better to restrict thr amount of turns to a maximum of ten and make longer heats: instead of 5 minutes there will be 8 minute heats which will be more competitiver so the guys and the back can also have a chance to get first. longer heats means better concentration and the chance is that even topdrivers like Hirosakaa and Hara will make mistakes in the last minutes so the others have a chance as well. Another rule could be adding some extra weight to the car if it has won a previous heat to slow it down. Just a thought.
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Old 01-25-2006, 12:20 AM   #64
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Quote:
Originally Posted by MrUnlimited
Instead of going to 4 cells it might be better to restrict thr amount of turns to a maximum of ten and make longer heats: instead of 5 minutes there will be 8 minute heats which will be more competitiver so the guys and the back can also have a chance to get first. longer heats means better concentration and the chance is that even topdrivers like Hirosakaa and Hara will make mistakes in the last minutes so the others have a chance as well. Another rule could be adding some extra weight to the car if it has won a previous heat to slow it down. Just a thought.

I would prefer the limit the number of cells,as thats 2 less cells to buy.And the cost of an higher turn hand wound mod is about the same as a low turn hand wound mod...
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Old 01-25-2006, 12:41 AM   #65
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Eddie; Ohms law. If I can recite it correctly: Voltage over resistance equals amperage. It's been 20 years since I studied it in night school in my electrical classes. If an electric motor had a fixed resistance, if you lowered voltage supplying it, it would reduce the amperage it consumes, therefore would run longer on the same battery. You can turn the formula around every way imagineable. But motors do not have fixed resistance with variable voltage... but that would be another discussion. You would not have the same wattage rating with a lower voltage input, but the wieght of the vehicle would be lighter and not need as much power. I am sure that "less ripp" would be felt, but the effects would be benaficial in the wear-n-tear dept.

bb
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Old 01-25-2006, 12:51 AM   #66
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Quote:
Originally Posted by MrUnlimited
Instead of going to 4 cells it might be better to restrict thr amount of turns to a maximum of ten and make longer heats: instead of 5 minutes there will be 8 minute heats which will be more competitiver so the guys and the back can also have a chance to get first. longer heats means better concentration and the chance is that even topdrivers like Hirosakaa and Hara will make mistakes in the last minutes so the others have a chance as well. Another rule could be adding some extra weight to the car if it has won a previous heat to slow it down. Just a thought.
Turn limits don't work. This has been proven in the US and Europe. Racers wind up the timing until the limited motors (10 or 12 turn) are as fast as open motors (7-8 turn). All that timing burns the motor up faster than running an 8 with less timing.
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Old 01-25-2006, 01:23 AM   #67
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I think this rule is completely worthless because I cannot see the point on this.

A lot of guys here call for "cost cut" on tires, Motors and batteries... on the other hands you can read everywhere about how much people look forward to brushless and LiPo a.s.o.

In my opinion, racing cars (no matter which size or class) will NEVER be cheap. If you want to save money or you cannot handle mod why not go stock ? I think it will be very boring to watch a big race with cars going slow.
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Old 01-25-2006, 01:33 AM   #68
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Quote:
Originally Posted by Manfredo
I think this rule is completely worthless because I cannot see the point on this.

A lot of guys here call for "cost cut" on tires, Motors and batteries... on the other hands you can read everywhere about how much people look forward to brushless and LiPo a.s.o.

In my opinion, racing cars (no matter which size or class) will NEVER be cheap. If you want to save money or you cannot handle mod why not go stock ? I think it will be very boring to watch a big race with cars going slow.

Isn't that going to happen in Formula 1??

Gone are the days where you hear 3Litre V10 scream!!
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Old 01-25-2006, 01:41 AM   #69
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Interesting views and opinions in this topic.

Just a thought.
Balancing the car with 4 cells on the right and all other electronic componenets on the left should not be a problem.

SERVO ------------- = 50 grams
RECEIVER ---------- = 13 grams
AMB --------------- = 15 grams
ESC+Capacitor+wires = 30 grams
MOTOR ------------- = 180 grams
TOTAL LEFT SIDE---- = 288 grams

4 CELL GP 3700 = 270 grams

It is with 6 cells that we need to add weight on left side of the car to counter act for the 405 grams of the new battery packs..

But still I hate when they try to decrease the power and performance of the cars.
In real life motorsport they are decreasing performance in order to try and keep some standards of safety.
This does not apply in R/C, so why bother with all these limitations?

John
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Old 01-25-2006, 01:57 AM   #70
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Quote:
Originally Posted by Jaybo
judging by the following data from the JRMCA site..

 15-3-11 重  量
    4WD(4輪駆動車)・1350g以上、2WD(2輪駆動車)・1250g以上
 15-3-15 バッテリー
   ④最高4セル(4.8V)まで使用できる。

it looks like the minimum weight is now @ 1350gm?
4WD, 1350 gram & 2WD 1250 gram. Is this realy Touringcars?
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Old 01-25-2006, 02:09 AM   #71
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My ONLY reservation about the 4-cell rule is voltage to the servos if you are not using an RX pack.

Adding an RX pack is extra hassle that most club racers would rather do without.

Other than that, I think the combo of lighter cars with less rip but actually similar laptimes is full of merit. It costs less without affecting the quality of racing. Should be an interesting year in Japan.
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Old 01-25-2006, 02:30 AM   #72
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Quote:
Originally Posted by John Doucakis
Interesting views and opinions in this topic.

Just a thought.
Balancing the car with 4 cells on the right and all other electronic componenets on the left should not be a problem.

SERVO ------------- = 50 grams
RECEIVER ---------- = 13 grams
AMB --------------- = 15 grams
ESC+Capacitor+wires = 30 grams
MOTOR ------------- = 180 grams
TOTAL LEFT SIDE---- = 288 grams

4 CELL GP 3700 = 270 grams

It is with 6 cells that we need to add weight on left side of the car to counter act for the 405 grams of the new battery packs..

But still I hate when they try to decrease the power and performance of the cars.
In real life motorsport they are decreasing performance in order to try and keep some standards of safety.
This does not apply in R/C, so why bother with all these limitations?

John
Your calcluation only works when everything seat on the same distant to centerline, which is not what happened in realife.

As my testing on weight placement, generally for side motor belt, you need 4 cells on the otherside to make it balance. And servo+ESC+RX+AMB would be balanced with 2cells.

You could add a ton to centerline and doesnt affect it's blanace (distant=0), it's all about weight x distant..
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Old 01-25-2006, 05:43 AM   #73
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Ive got an idea instead of 4 cells.
Run only brushless! No brushed motors at all.
let brush motor be history.
They wont have these problems of burning out - throwing winds etc
Brushless has to be the way to go just wish it would hurry up and take over!
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Old 01-25-2006, 05:55 AM   #74
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It changes nothing.... although?

1) we wil still dump (so batteries are as important, now you will need even more the voltage)
2) cars will be missiles (so the differences between the good and less good drivers will become even bigger)
3) tyres will wear even faster than before
4) cars will be redesigned for optimising weight balance (which cost money... who pay: yes, you...) as well manufacturers need to make different cars for different regulations.
5) batteries will NOT become cheaper I will quess, but stay same price (but you get only 4 iso 6)
6) You will NEED another or extra BEC system (as the voltage will drop too much while accelerating at the end of the race)

But

1) You can have more racers attending = more money for the organisers
2) Racers can drive more packs if not more racers will attend
3) You have to concentrate only 5 minutes, which makes you less tired (but for that more time to drink beer which makes you more tired)
4) You have less time in the cold, sun or rain when marshalling
5) An extra argument for your wife to buy a new car/spend more money on your hobby (but they changed the rules, its not my fault honey!)
6) Team battery cost will go down by 40%! I will ask for a payrise immediatly!

But, rule changes are a great new challenge.... for the ones that have enough money. My opinion...
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Old 01-25-2006, 06:22 AM   #75
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Quote:
Originally Posted by Oscar Jansen
But, rule changes are a great new challenge.... for the ones that have enough money. My opinion...
True
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