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Old 01-01-2014, 06:41 AM   #646
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The impact of changing to a long-arm set-up is very small. As the front of the car rolls less than 2mm, the camber change is very small.

Putting a spacer between the upper wishbone mount and the mounting block will give a long-arm set-up and less camber change. Putting a spacer between the mounting block and the lower wishbone will widen the the front width. As H I says...

The bigger change in making the top wishbone 'long' is to lower the front roll centre. That reduces the tendency to grip roll, and reduces the 'bite' of the steering on high-grip tracks. I suspect that the change to roll centre is why this is done, and not so much the change to camber gain.

The lower roll centred will make the car softer in roll, and is usually accompanied by use of softer rear springs. Again, contrary to the usual thinking in On-Road, as the grip goes up making a 12th car softer helps.

Remember that 12th is the only car in the world with a hinge in the middle of the chassis. That means that a lot of the accepted wisdom of race-car set-up doesn't apply. When the main chassis rolls, it uses the centre spring to remain level. As the car turns, the front axle is levered around the centre pivot, the centre shock and the front springs - it's complicated! My experience is that roll centres and weight transfer (position of the rear pivot relative to the rear axle) play a bigger part in getting a car to handle than camber gain. HTH

Last edited by SlowerOne; 01-01-2014 at 07:54 AM.
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Old 01-01-2014, 07:56 AM   #647
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Originally Posted by bigcracing View Post
That's what I thought when you look at the setup that how I would interpret it longer upper arm and narrow front end and if you add on the lower arm it would give you a wider front end

Does anybody have a Mazda 12th scale body that we ran in the early 90s

Thanks chris
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Old 01-01-2014, 03:41 PM   #648
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Not the same we use to race it in the early 90s it didn't have a separate wing I thought it was a Mazda

Thanks Chris
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Old 01-01-2014, 03:43 PM   #649
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Not the same we use to race it in the early 90s it didn't have a separate wing I thought it was a Mazda

Thanks Chris
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Old 01-01-2014, 10:55 PM   #650
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Quote:
Originally Posted by SlowerOne View Post
The impact of changing to a long-arm set-up is very small. As the front of the car rolls less than 2mm, the camber change is very small.

Putting a spacer between the upper wishbone mount and the mounting block will give a long-arm set-up and less camber change. Putting a spacer between the mounting block and the lower wishbone will widen the the front width. As H I says...

The bigger change in making the top wishbone 'long' is to lower the front roll centre. That reduces the tendency to grip roll, and reduces the 'bite' of the steering on high-grip tracks. I suspect that the change to roll centre is why this is done, and not so much the change to camber gain.

The lower roll centred will make the car softer in roll, and is usually accompanied by use of softer rear springs. Again, contrary to the usual thinking in On-Road, as the grip goes up making a 12th car softer helps.

Remember that 12th is the only car in the world with a hinge in the middle of the chassis. That means that a lot of the accepted wisdom of race-car set-up doesn't apply. When the main chassis rolls, it uses the centre spring to remain level. As the car turns, the front axle is levered around the centre pivot, the centre shock and the front springs - it's complicated! My experience is that roll centres and weight transfer (position of the rear pivot relative to the rear axle) play a bigger part in getting a car to handle than camber gain. HTH
Damn...I have to wrap my brain around this
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Old 01-03-2014, 06:29 PM   #651
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My car was "OK" compared to previous runs this past race. I made a few changes based on Ivy's setup but i think the car can be faster or more consistent if not faster.

One thing I did notice was the car ran it's fastest when the tires got around the diameter of the setup sheet. I also noticed the front tires coned outward by the time they wore down. is that normal for 12th scale?
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Old 01-03-2014, 06:36 PM   #652
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From my understanding of some 1/12th knowledge, coning is not acceptable. I'm sure someone will correct me if I'm wrong. And setups are cool and a nice base the majority of the time, but almost always they have to be tailored to what you like in the drivability of a car.
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Old 01-03-2014, 06:41 PM   #653
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Quote:
Originally Posted by JayBee View Post
From my understanding of some 1/12th knowledge, coning is not acceptable. I'm sure someone will correct me if I'm wrong. And setups are cool and a nice base the majority of the time, but almost always they have to be tailored to what you like in the drivability of a car.
It's hard to tell since sometimes coning is ok and other times it's not.

I only made a few changes based on the setup, didn't go 100% but the changes i made were positive so Ivy's onto something.
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Old 01-04-2014, 09:05 AM   #654
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Hey Dorian,

If Your Tires are coning you can Adj your camber + or Neg till your tires run flat.

Hope this helps
Mike
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Old 01-26-2014, 09:26 AM   #655
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.

Last edited by Josh Keller; 01-28-2014 at 05:11 PM.
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Old 01-31-2014, 04:32 AM   #656
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Default body mount position

Does anybody know if the body mount positions are the same between a
RC12R5.1 (non inline ) and the RC12R5.2 chassis ?

I want to prep a body already but currently only have a RC12R5.1 ( non inline ) as a reference .

Thanks,
Erik
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Old 01-31-2014, 06:30 AM   #657
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Quote:
Originally Posted by stical View Post
Does anybody know if the body mount positions are the same between a
RC12R5.1 (non inline ) and the RC12R5.2 chassis ?

I want to prep a body already but currently only have a RC12R5.1 ( non inline ) as a reference .

Thanks,
Erik
same on front, about 1 cm back rear.
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Old 02-01-2014, 09:33 AM   #658
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Questions??

Does anybody know if you can use the 5.2 (V2)lower arms on the 5.1 front bulkheads? Or do you have to buy the newer bulkheads?
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Old 02-01-2014, 10:58 AM   #659
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You will need the new bulkheads with the new arms.

The old setup screws into the arms and the new setup screws into the bulkheads.
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Old 02-01-2014, 11:09 AM   #660
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Quote:
Originally Posted by RacinJ View Post
You will need the new bulkheads with the new arms.

The old setup screws into the arms and the new setup screws into the bulkheads.
Doh! my bad. Didn't even think about that.
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