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Old 03-23-2008, 08:50 AM   #1
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Exclamation Backwards Lipo use: Time to evolve Peoples.

This came from the claimed Lipo Discharge and SMC Lipo threads indirectly. Per some going about the nimh that were used at carpet nats. I'm sure the below has probably been mentioned before, but I don't think has seriously been discussed.

So far the thinking with lipos has been backwards versus forwards. I'm mostly speaking about weight and dimensions. Instead of truly taking advantage of what lipos can offer, 1/10th is going the opposite direction and handicapping lipos to make it "fair" for the nimh. Does anyone really believe a nimh will still be used in top tier when lipos cars can potentially weigh much less and balance better?

Now, before I get the argument/hypothesis:

"Dude, Lipos are too light to balance sedans".

WRONG!. How much silly weight are you guys adding to them to get the cars to balance left to right and make minimum spec? Does that make any sense?

Here is the biggest flaw with all current 1/10th Lipo packs. Orion started it all, and no one has of yet taken the initiative to challenge the old school Nimh dimensions set. In short, make a Lipo 7.4 the size of a 4cell Nimh.

From looking at lipo dimensions, though there is nothing current with what Im speaking of: 92mm X 45mm X 23mm. From estimating how the latest generation of lipos dimensional areas comes to. It would be very possible to create a 3000+mah pack in a 4 cell dimension.

"A 3000mah wont last the race man."
Your right! If your thinking of minimum ROAR spec weight. If however, you throw these out the window (which is about time). I believe its very possible. Though this is all theory since I cannot prove it without any packs on the market to use as an example.

"Ok fine, but now my sedan is way out of wack with left to right balance."
Well, have to say it. Guys, we smaller scales have already worked around this. (Micro jab) We seem to be on the forefront with new tech and ideas more than you conservative larger scales.(end jab).

It boils down to this. You put some of your electronics on the battery side. Don't think this will have a better balance ratio? I went and got some numbers! (Mu ha ha ha!)

Orion 3200 Lipo: 285g
Assembled 4200 Nimh: 445g

Now, I'm taking the assumption a "squashed" 3000 would be around the same weight as the Orion.

Idea A: Servo + Lipo on left.

Lengths:
This "X" lipo would be no longer than 92mm. That leaves about 44mm of space in front where normally the other two cells would be. Depending on the chassis, you could fit the servo in front where those went.

92L mm (X lipo) + 42L mm (Used s9550) = 134mm total. A 4200 pack is about 136mm.

Weight:
Left Side:
285g (X Lipo) + 46g (S9550) = 331g

Right Side:
12g (Receiver) + 30g (ESC) + 10g (wiring) + 189g (17T Spec Brushless) = 241g

L:331g - R:241g = 90g difference.

After balancing out L to R and F to R the total electronics weight (minus transponder): 662g!

Idea B: ESC (possible Receiver as well) + Lipo on Left.

Lengths:
92L mm (X lipo) + ~38L mm (Brushless ESC) = 130mm total.

Weight:
Left Side:
285g X Lipo + ~35g ESC w/wires = 320 grams

Right Side:
46g (servo) + 12g (receiver) + 7g (wire) + 189g (motor) = 254g

L:320g R:254g = 66g difference.

After balancing out L to R and F to R the total electronics weight (minus transponder): 640g!

"Your forgetting the cars were designed for the greater weight. They wont handle well being so light"
With the multitude of adjustments, springs, and tires available. This can be overcome IMOHO. Is this unmarked territory where you no longer can have the same setups you used before? Yes. I believe most of us racers are tweakers at heart, and might like the challenge of discovering the new hot setups with this weight. Heck, think of advantages you guys will get with tire wear and lower possible damage from wall smacks.

So my challenge is this. For a Lipo creator to release a Hard case lipo with the above dimensions: 92mm X 45mm X 23mm. With the specific note its not currently for Roar use (per adding all that weight will kill its advantage and runtime). Orion released Lipos before having to get ROARs permission.

Someone needs to at least try this behind closed doors before dismissing it. Its pretty much become a speed secret for 1/18th racers (shorter lipo packs).

The only advantage left for the larger lipo packs if this theory proved correct, would be for endurance racers, or if racing time was increased significantly.
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Old 03-23-2008, 09:03 AM   #2
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Your logic makes some sense and I wish we could go this route. Some guys at out track are running Vintage Trans Am with Xrays and RDXs. They run the 4 cell battery, so they have room to put their speedo over there with it. Car looks awesome, everything has a place, instead of being all stacked up on the one side.
But we live in a world where people base opinions on things they've never tried themselves and will kill the sport before opening their minds.
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Old 03-23-2008, 09:41 AM   #3
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It seems like the actual cells we're using are longer, making it hard to shorten the packs. I don't know if/what is available in shorter cells, at least not with the capacity we're after. Also, with ROAR stepping up and defining the Orion brick as the "standard" size, everybody has tooled up to use those dimensions. It would be hard to turn back now. But, if someone could create a shorter brick and leave room on the right for electronics, maybe people would bite. I don't think it would be ROAR legal, which could affect buying decisions.

If you use light servos, light ESC's, light transponders and light receivers, you can get things to balance decently well. The brushless/ESC weight is still challenging, but the trend to move motors closer to the centerline is helping, and brushless ESC's are evolving.

Even though adding weight feels like a penalty, it's only fair right now during this time of transition. And really, lighter cars will be faster, and we don't need to be faster right now.

Adding weight with LiPo still has some perks. You get a lot of flexibility on where you put your weight, possibly allowing for better ballast. You can also easily ensure that you're exactly at the minimum weight, which other cars might struggle with.
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Old 03-23-2008, 10:49 AM   #4
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i run my car light. jrxs-r with orion 3200's and novak brushless. it's perfectly balanced left to right. the only sucky part is that the weight is somewhat rear biased so i had to do some playing around with the setup to get it to steer.

i love it. tires wear significantly less, they last longer. hits aren't as hard due to the reduced mass. handling is a dream. speed is absurd, i gear the snot out of a 13.5 (standard rotor even) and get close to 10.5's. 10.5 feels about as fast as mod did about 5 years ago at this weight.
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Old 03-23-2008, 11:58 AM   #5
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Syndrome, neither was the Orion Roar legal when it first came out..

"If you build it, they will come"

RussB's experience is what I'm talking about. How can less tire wear, motor wear, and damage from hits be ignored when we are desperately looking for new blood? All in the name of keeping it fair.
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Old 03-23-2008, 12:08 PM   #6
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Quote:
Originally Posted by RussB View Post
i run my car light. jrxs-r with orion 3200's and novak brushless. it's perfectly balanced left to right. the only sucky part is that the weight is somewhat rear biased so i had to do some playing around with the setup to get it to steer.

i love it. tires wear significantly less, they last longer. hits aren't as hard due to the reduced mass. handling is a dream. speed is absurd, i gear the snot out of a 13.5 (standard rotor even) and get close to 10.5's. 10.5 feels about as fast as mod did about 5 years ago at this weight.
I can back him up, his car worked awesome all day! He was hooked up all day, and he ran quick all day (cold, to hot track)

I dont think you were any faster then I was on the straight tho, I met up with you, and you werent faster, till the infield
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Old 03-23-2008, 03:09 PM   #7
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Boy... ROAR finally allows LiPo and sets some basic size/safety rules and you want to go and change things already

Give it a few years to let guys get used to LiPo and for cars to be designed around Lipo. I am sure ROAR and the other National bodies will tweak the rules as needed.

Change can be good but a little stability is good for the hobby also.
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Old 03-23-2008, 03:30 PM   #8
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I like the idea of smaller battery pack. Already LiPO's have a capacity advantage by making use of voids that cylidrical cells create.

Do we really need 6000mah LiPO's for 5 min races for any racing class?
If the mod racing was able to get by with 1500mah few years back, I am sure they can get by with 2000 or 3000mah.

Used to be racing was about proper gearing and smoother driving to finish a race without dumping. Now racing is about maximum motor rollout and the only worries are if the motor is going to fry or not.

Besides a smaller LiPO maybe lower voltages wouldn't hurt either. Across the pond in Europe they are running 5-cell. Pan cars are running 4-cells. Lossing up to 150g in battery weight can make the cars more durable. I have tried a 2300mah 6.6V A123 pack in my oval car. Even with exactly half the capacity of my EP4600's 4.8V pack, that pack lasted a strong 8min befor dumping on a 13.5motor.
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Old 03-23-2008, 05:37 PM   #9
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The next generation of sedans will look more like the HPI Pro2, Tamiya 414, Schumacher SST, Yokomo YR-4M and Xray T1. Saddle pack Lipo, motor in the middle, servo on one side speedo and rx on the other...perfect balance, no added weight, no compromises to suspension geometry or weight distribution.
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Old 03-23-2008, 05:39 PM   #10
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Quote:
Originally Posted by AdrianM View Post
The next generation of sedans will look more like the HPI Pro2, Tamiya 414, Schumacher SST, Yokomo YR-4M and Xray T1. Saddle pack Lipo, motor in the middle, servo on one side speedo and rx on the other...perfect balance, no added weight, no compromises to suspension geometry or weight distribution.
next generation is already here. Losi Type R , Team Magic E4 both perfect balance without adding any extra weight
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Old 03-23-2008, 05:42 PM   #11
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Quote:
Originally Posted by AdrianM View Post
The next generation of sedans will look more like the HPI Pro2, Tamiya 414, Schumacher SST, Yokomo YR-4M and Xray T1. Saddle pack Lipo, motor in the middle, servo on one side speedo and rx on the other...perfect balance, no added weight, no compromises to suspension geometry or weight distribution.
Problem still being making weight for roar racing...
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Old 03-23-2008, 05:55 PM   #12
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Wouldn't another alternative be for a company to produce a chassis that had a stronger thicker bumper and suspension parts which made the car significantly more durable. Probably not a big deal for "pros" who never hit anything, but for others a more durable crash resistent vehicle would be plus.

It seams like a waste to put dead weight on a vehicle. If there is a madatory weight, then it would make sense to have that weight put where it might provide some advantage.

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Old 03-23-2008, 06:28 PM   #13
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Quote:
Originally Posted by rx7ttlm View Post
Problem still being making weight for roar racing...
For now. Minimum weights will drop and cars will go back to saddle packs.
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Old 03-23-2008, 06:41 PM   #14
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attached is a picture of half of a 6s2p 22.2 volt 4400 mah lipo battery from my helicopter, it is 4 inches (i'm using inches, hope thats ok) by 1 by 1.25 for two of the cells, each cell is 2200 mah, what you are suggesting is being done/tested.

however in the big picture, weight isn't always the enemy, in off road, guys are ADDING weight, to make the car work better, from what i am hearing some are adding a extra 6oz of lead to the car, thats 6oz over what roar calls for, i've been struggling to get my trans am car hooked up on carpet for the entire 8 mintue race, so far its only been good for 6 or 6 1/2 minutes before getting loose. i was running the car at the min weight, this morning i actually added weight, stiffened the car up, and it went over 10 minutes without a slip and .4 faster. (more corner speed).

oh, i almost forgot my micro jab, if the purpose of your post was to get my sedan to handle like micros at sir, ahh, no thanks.
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Backwards Lipo use: Time to evolve Peoples.-dscf0496.jpg   Backwards Lipo use: Time to evolve Peoples.-dscf0497.jpg  
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Old 03-23-2008, 07:59 PM   #15
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Saddle packs are one solution, yes. Thats still taking the same total dimensional space that could be better suited with electronics shifting.

As it is, there are many vehicles right now on the market that would be better suited for a 4 cell dimension. Many Sedans, Off roads, Tamiya Minis, some 1/12ths, some 1/10th pans. The list goes on and on. With a shorter 4 cell design it opens up for weight placements by moving electronics around, allowing you to add weight to the >exact< area you need since you don't have all that wasted area encompassed by a larger pack.

Versus now with many sedans I have seen throwing tons of lead weights on current lipos just to balance the car out.

(Ya got my Skypilot, though we all don't drive like Sal )

Edit: I translated your ancient measuring system: 101mm X 32m X 26mm ...

What I was suggesting was 92mm X 45mm X 23mm. The dimensions I listed is a bit shorter, but much wider which should allow a 3000+ rating (in theory).
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