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Old 02-12-2013, 09:22 AM   #1
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Default traction roll, use higher or lower roll center?

Some say higher some say lower for traction roll at high speed out of corner. Which one is true?
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Old 02-12-2013, 09:29 AM   #2
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Both.

In my opinion there are 2 types of traction roll, the one that happens as soon as you dive into the sweeper (when you touch the steering) and the one that happens more mid late corner.

The initial traction roll is be best counteracted by a lower roll center, to mellow the car down.

The mid to late corner is probably generated by too much body roll and would benefit from a higher roll center.
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Old 02-12-2013, 09:42 AM   #3
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Both.

In my opinion there are 2 types of traction roll, the one that happens as soon as you dive into the sweeper (when you touch the steering) and the one that happens more mid late corner.

The initial traction roll is be best counteracted by a lower roll center, to mellow the car down.

The mid to late corner is probably generated by too much body roll and would benefit from a higher roll center.
+1 for this
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Old 02-12-2013, 10:04 AM   #4
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Having shown up at the IIC with a very low-traction setup on my touring car and spending the first few days trac-rolling every corner, I would recommend taking nearly all of the droop out of the car, down to about 2mm or less, and bigger swaybars front and rear. Also, widen the front track width as far as you can and still be legal.
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Old 02-12-2013, 10:42 AM   #5
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Having shown up at the IIC with a very low-traction setup on my touring car and spending the first few days trac-rolling every corner, I would recommend taking nearly all of the droop out of the car, down to about 2mm or less, and bigger swaybars front and rear. Also, widen the front track width as far as you can and still be legal.
Everything you said will hurt you except making the front wider.

U need the chassis to roll to stop traction rolling. If the car is still rolling while you start to get the wheel straight you will never traction roll.

Also soft springs will help alot.
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Old 02-12-2013, 10:57 AM   #6
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Everything you said but making the front wider hurt you.

U need the chassis to roll to stop traction rolling. If the car is still rolling while you start to get the wheel straight you will never traction roll.

Also soft springs will help alot.
Wouldn't a 1mm or so spacer between the hex hub and wheel help? I switched to thicker hexes and they seemed to help.
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Old 02-12-2013, 11:03 AM   #7
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Originally Posted by nitrobeast View Post
Everything you said but making the front wider hurt you.

U need the chassis to roll to stop traction rolling. If the car is still rolling while you start to get the wheel straight you will never traction roll.

Also soft springs will help alot.


+1
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Old 02-12-2013, 11:06 AM   #8
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Wouldn't a 1mm or so spacer between the hex hub and wheel help? I switched to thicker hexes and they seemed to help.
Maybe i didnt word that correctly. Making the front wider will help, the other stuff will hurt.
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Old 02-12-2013, 11:31 AM   #9
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Maybe i didnt word that correctly. Making the front wider will help, the other stuff will hurt.
Less droop and thicker swaybars means more trac roll? Not in my experience...
If my car goes around corners on its door handles it would load up on the outside front tire, hook the outside edge, and roll straight over on the nose... so I went back to the foam tire roots and took the droop out of it. What am I missing?
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Old 02-12-2013, 12:09 PM   #10
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My only advice is to research roll centers. I had the same question months ago. researched the full scale racing forums and learned a lot. When it comes to roll center you need to know how to find it, how to adjust it and how it affects the handling of your car. You also need to understand roll center in relation to center of gravity and the roll axis. you are entering some advanced tuning. Learn as much as you can.

To answer your question in most circumstances you raise the roll center to help traction roll but as others have pointed out it depends on how the car is rolling. Sometimes you need to lower it and make other adjustments to get the desired result.
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Old 02-12-2013, 12:11 PM   #11
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http://www.rctech.net/forum/electric...ll-center.html
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Old 02-12-2013, 12:55 PM   #12
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Less droop and thicker swaybars means more trac roll? Not in my experience...
If my car goes around corners on its door handles it would load up on the outside front tire, hook the outside edge, and roll straight over on the nose... so I went back to the foam tire roots and took the droop out of it. What am I missing?
I hear what you are saying about foam days, but i dont think you can compare foam to rubber. Foam tires are usually ran really small compared to a rubber tire and corner speed might also have something to do with it....

FYI, i have some Duo 1 13.5's, if you are interested send me a PM.
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Last edited by nitrobeast; 02-12-2013 at 01:13 PM.
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Old 02-12-2013, 12:58 PM   #13
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I've tried high droop settings all the way to no droop and I've found that more droop in high traction make chassis dig in and roll the car but it would also roll if I didnt have any droop . when I removed droop it was a instant roll "snap roll" but with a lot of droop it rolled near apex of turn. I then thicked oil and raised rear role center and problem was fixed but it didn't have the traction it did have in the rear .
With the thicker oil and no droop , guess what car snap rolled even easier . Lol
Run as much droop as u can is what I've learned . I'll start with 6mm of up travel and work down until car feels good . So far about 3.5droop f/r of my t4 works great on our high traction track .
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Old 02-12-2013, 01:43 PM   #14
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Quote:
Originally Posted by nitrobeast View Post
I hear what you are saying about foam days, but i dont think you can compare foam to rubber. Foam tires are usually ran really small compared to a rubber tire and corner speed might also have something to do with it....

FYI, i have some Duo 1 13.5's, if you are interested send me a PM.
Well, when I took the droop out of the rear and went to my hard front swaybar, it stopped trac-rolling. Maybe it's just my car.
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Old 03-01-2013, 08:55 AM   #15
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Originally Posted by napoleon1981 View Post
Both.

In my opinion there are 2 types of traction roll, the one that happens as soon as you dive into the sweeper (when you touch the steering) and the one that happens more mid late corner.

The initial traction roll is be best counteracted by a lower roll center, to mellow the car down.

The mid to late corner is probably generated by too much body roll and would benefit from a higher roll center.
You mean do the adjustment on front or rear or both?

What if traction roll in both situations, corner entry and at mid corner?
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