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Old 01-31-2005, 04:33 PM   #31
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In one word, yes. Having weight as centered as possible helps handling. I am sure there are exceptions to every rule, but when it comes to onroad you want the weight centered. As for the dirt cars you first mentioned, it's easy to place the batteries down the center becasue they are only 2 wheel drive, no driveshaft/belts to get in the way
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Old 01-31-2005, 04:41 PM   #32
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tes mounting the batterys down the center makes it more agile my first car was a TA04 and with the baterys mounted as they are it was very hard to turn at high speeds so i gto a xray. the xray splits the cells becasue the motor is bassicaly in the center and teh Rx/servo/ESC work each other out so if ya just put the cells down one side then its all sorted.. so th reson they use saddles is to ballance not for any performance advantages.. although having teh saddles as close to the belt as bossible would make a HUGE advantage.. i think a good design for this would be a shaft with 2 half stick packs

see the pic only problem is equalising these style pacs would be hard ish
which is why saddles /ladders are used
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Old 01-31-2005, 04:49 PM   #33
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Xray has the best belt design and HPI has the best shaft design. The reason is that they are the lowest and most centralized of all the cars in the weight distribution department. I can definantly feel the balance of the saddle packs and the central motor in my Xray, but when I raced the Pro 4 I could get better traction because it had a lower CG.

As far as the shaft drive and centered batteries, The car would need to use extra gears or 2 CVD's to connect the drivetrain. This would cause extra friction and reduce the useful output relative to the total input, a.k.a. Efficiency.

The Xray FK is the best overall design because you get centralized batteries, motor, and drivetrain. The only downfall is the higher CG of the rotating drivetrain.
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Old 01-31-2005, 04:59 PM   #34
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Quote:
Originally posted by merc-blue
tes mounting the batterys down the center makes it more agile my first car was a TA04 and with the baterys mounted as they are it was very hard to turn at high speeds so i gto a xray. the xray splits the cells becasue the motor is bassicaly in the center and teh Rx/servo/ESC work each other out so if ya just put the cells down one side then its all sorted.. so th reson they use saddles is to ballance not for any performance advantages.. although having teh saddles as close to the belt as bossible would make a HUGE advantage.. i think a good design for this would be a shaft with 2 half stick packs

see the pic only problem is equalising these style pacs would be hard ish
which is why saddles /ladders are used
I Was toying with and idea similar to that but I can't figure out what to do with the motor. You will either have to offset it to one side like most current shaft cars or run it either above or below the shaft, not really ideal for CG height.

As far as situations where a low polar moment is not ideal, low bite condtions can favor a high polar moment where too quick of a direction change can lead to a loss of traction but too much of a high polar moment can make the car continue to rotate when trying to exit a corner. This is why there will never be a "best" car as certain designs favor certain conditons over others.
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Old 01-31-2005, 05:29 PM   #35
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How about this...I remember seeing one of the micro (24th scale or something) cars that was 4 wheel drive and the motor shaft was also the driveshaft. Not really feasable with 10th scale because of obvious gearing limitations, but talk about keeping things centered!
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Old 01-31-2005, 11:06 PM   #36
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I prefer my batteries down the middle

Ginsu-You will have all these guys go back and fourth on which is better. With all my testing of the JRXS all I can tell you....is centralized weight is very important. Our XXX-S had a very wide mass on each side of the car. The most of any current TC on the market. So with all my testing having the weight on the sides is somewhat of a disadvantage. Why not have the car light enough and have the batteries centered? Then you can now test with weight bias on each side of the chassis. I hope this makes sense to you. You can easily put your weight bias anywhere on my car. At the DHI Cup I was 2.5 oz under weight. That is a lot of weight to play with weight bias around the car.
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Old 02-01-2005, 02:01 AM   #37
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All touring cars are a compromise, it just depends on which area manufacturers are willing compromise on.

Losi seemed to have worked out that the best balance is obtained by running the cells down the centre, and they are willing to sacrifice some loss of drivetrain efficiency in order to get the best possible chassis balance.

Remember there are a lot more corners on a track than straights
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Old 02-01-2005, 04:42 AM   #38
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Default Of course its better

Center of gravity



This isn't hard to define, you want a strait answer.

Will having all the weight centered in the car be better.

I would think this is more fact then opinion, but you want the lowest and most centered center of gravity in any and all forms of racing, cept maybe horse racing.


I drove a few kx-1 and pro 3, the kx-1 was awsome, as for the pro 3 hpi didn't seem to are to much about racing at the time and that car was really inconsistent because of poor molds and bad quality.

Losi doesn't look like there screwing around. There making and CG racing professional racing machine.

shafties will always have flaws
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Old 02-01-2005, 07:26 AM   #39
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Quote:
Originally posted by T. Hodge
I prefer my batteries down the middle

Ginsu-You will have all these guys go back and fourth on which is better. With all my testing of the JRXS all I can tell you....is centralized weight is very important. Our XXX-S had a very wide mass on each side of the car. The most of any current TC on the market. So with all my testing having the weight on the sides is somewhat of a disadvantage. Why not have the car light enough and have the batteries centered? Then you can now test with weight bias on each side of the chassis. I hope this makes sense to you. You can easily put your weight bias anywhere on my car. At the DHI Cup I was 2.5 oz under weight. That is a lot of weight to play with weight bias around the car.
Thanks Todd, I think you have convinced me. I will purchase the Losi over the Xray....I hope to see you at the Birds.
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Old 02-01-2005, 07:27 AM   #40
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Default Re: Of course its better

Quote:
Originally posted by TCR
Center of gravity



This isn't hard to define, you want a strait answer.

Will having all the weight centered in the car be better.

I would think this is more fact then opinion, but you want the lowest and most centered center of gravity in any and all forms of racing, cept maybe horse racing.


I drove a few kx-1 and pro 3, the kx-1 was awsome, as for the pro 3 hpi didn't seem to are to much about racing at the time and that car was really inconsistent because of poor molds and bad quality.

Losi doesn't look like there screwing around. There making and CG racing professional racing machine.

shafties will always have flaws
Nice Post, thanks
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Old 02-01-2005, 05:04 PM   #41
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Quote:
Originally posted by Ginsu
Thanks Todd, I think you have convinced me. I will purchase the Losi over the Xray....I hope to see you at the Birds.
Are you serious? Did you think he was going to say anything bad about the JRXS? Of course not, he is the head honcho for Losi racing. If your so easily convinced, go on the Xray forum and talk to Ralph Burch, Hudy, Tony, or Mario. The Xray is just as balanced as the JRXS. Infact, Xray was the only company to stick with the balanced chassis over the last four years.

If you want the JRXS, get the Xray FK and then buy the JRXS 9 months after they are available. That will give Losi time to evaluate the durablity in the hands of the average joe. Then they will make running changes and you should have a strong and fast car.
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Old 02-01-2005, 05:53 PM   #42
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Default Re: Of course its better

Quote:
Originally posted by TCR
I would think this is more fact then opinion, but you want the lowest and most centered center of gravity in any and all forms of racing, cept maybe horse racing.[/B]
nahh oval racing not necessarily centered.
and horse racing hmm. does cg count for anything in that?
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Old 02-01-2005, 07:52 PM   #43
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Default holy johnny

what?
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