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Which is more important? Upper link length, or roll center

Which is more important? Upper link length, or roll center

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Old 09-21-2007, 05:55 AM
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Default Which is more important? Upper link length, or roll center

I am building a Traxxas SRT for mild racing ( I got a T4 for the hardcore stuff). I noticed that traxxas has two different bulkheads, one is for Nitro and has 6 holes laid out in two rows of three horiziontal per side, the electric has 6 as well But laid out vertical, Two rows of three. My question is, Which is more important? The length of the link (horiziontal) or roll center (vertical)?

I would prefer opinions from experienced racers and no drop it for a T4 or XXX-t, I already got a T4 and this is just a fun project.

thank you for any info
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Old 09-21-2007, 11:09 AM
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Both the length of the link and height of the link affect roll center. However, I do adjust height more than I adjust length.
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Old 09-21-2007, 11:13 AM
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Length is more of a drastic change than height.
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Old 09-21-2007, 11:26 AM
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Well changing the link length will actually change your camber gain, not the roll centre, since the camber links angle relative to the lower arm is still the same. Raising/lowering the inner or outer mounting point of your camber link will change the roll centre. Both are important, but you can sort of feel a change in camber link length more than a roll centre change (depends on the difference in height though of course).
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Old 09-21-2007, 02:33 PM
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Thanks guys. I don't yet know officially if the Nitro bulk will fit, I'm sure it will, but you gave me some things to think about.
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Old 09-21-2007, 02:37 PM
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Both are good adjustments to have but do similar, but quite different things to handling. Raising the roll center will improve grip on that end of the car due to greater weight transfer. I find this is just about the only adjustment I make on my AD2 is the # of washers under the front inner ball stud: one more for less steering, one less for more steering.

Now changing the camber link length will primarily only affect the way in which the vehicle rolls, not how much. A short stubby link will allow the vehicle to roll very easy and not "square up" very well. Using a shorter link in the rear will cause the vehicle to flow through corners very well, but too much and it will want to drift all over and never be planted. A longer rear link is better for driving for point to point. The rear would then feel very planted and be able to "square up" corners with ease. Going too far in either direction is, of course, bad.

If you are not sure where to start I would recommend using the holes that will make the link parallel the the arm and make the front link just a little shorter than the rear.
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Old 09-21-2007, 02:59 PM
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Originally Posted by gubbs3 View Post
Both are good adjustments to have but do similar, but quite different things to handling. Raising the roll center will improve grip on that end of the car due to greater weight transfer. I find this is just about the only adjustment I make on my AD2 is the # of washers under the front inner ball stud: one more for less steering, one less for more steering.

Now changing the camber link length will primarily only affect the way in which the vehicle rolls, not how much. A short stubby link will allow the vehicle to roll very easy and not "square up" very well. Using a shorter link in the rear will cause the vehicle to flow through corners very well, but too much and it will want to drift all over and never be planted. A longer rear link is better for driving for point to point. The rear would then feel very planted and be able to "square up" corners with ease. Going too far in either direction is, of course, bad.

If you are not sure where to start I would recommend using the holes that will make the link parallel the the arm and make the front link just a little shorter than the rear.
Thanks a lot, thats good info. I am already pretty good at setups, but i noticed these two options and wasn't sure which way would be prefered. Going by the last post, I think i should stay with the electric bulkhead ( vertical) but will pick up the Nitro one and test one day. Once again, thanks
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