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Old 05-02-2011, 10:20 AM   #1
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Default Car flips/rolls over during cornering - quick fix

During a race in my local track recently, I encountered this problem.

Info of the race:
Track: high grip asphalt (indoor)
Car: 1/10 touring
Tires: slick rubber (36R)
Class: 10.5t with turbo & timing.

2 days before the race, car was set up nicely.
Car planted coming in & out of corner at high speed, stable, no issue whatsoever.

On race day, new layer of sugar water applied on the track, which resulted high grip surface.

During heats & finals, my car always flipped (roll over) coming out from corners (esp sharp corners).
I tried changing to softer spring (front), but the problem still persisted.

One funny thing about this, my car was the only one in the field which kept on roll over at corners.

Just curious, if I encountered such problem again, what is the quick fix??
Changing roll centre? higher or lower?

Please advise.
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Old 05-02-2011, 10:55 AM   #2
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Sounds to me like it's just grip rolling. You would probably want to loose a bit of rear grip but without knowing your chassis/setup it's hard to say what to do mate.
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Old 05-02-2011, 11:36 AM   #3
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Go up with shock oil, maybe the car is rolling to the end of suspension too soon or fast. Slow the roll
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Old 05-02-2011, 12:23 PM   #4
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You may want to cut down on front droop and/or go with stiffer front springs to limit roll.
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Old 05-02-2011, 12:29 PM   #5
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Glue the front side walls. No more traction roll.
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Old 05-02-2011, 05:02 PM   #6
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Quote:
Originally Posted by jammincrtjames View Post
Glue the front side walls. No more traction roll.
This is the "quick fix" and honestly sometimes the best.

Without knowing your setup it's hard to find the real issue. Softer springs will make that problem worse, you need to stiffen up that car, with oil, springs, swaybars, something, you need to lose traction in some form. plus it could be fliping off the front or the rear, blagh blagh blagh...

without seeing it makes it tough as well. The super glue holds up the tire side wall, and makes the car have a push, you lose a tick of steering, ( sounds like you have some to give) but your car stops fliping off the track.
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Old 05-02-2011, 05:32 PM   #7
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Actually you want it to roll more. To do so you will need to increase droop and lower you're roll center.

When you're car traction rolls, its because there are forces pushing on the car to rotate on its outside wheel as it turns. If the car doesn't roll and the forces are great, the car will pivot on the outside tire lifting the inside tire. The inside tire lifts because there's not enough droop to maintain contact with the surface. Hence the need to add droop. To prevent the forces from pushing hard enough to pivot your car on the outside wheel, you need to make the car roll more. The rolling action sucks up that force which would otherwise pivot your car at the wheel if it didn't roll.
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Old 05-02-2011, 05:37 PM   #8
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Quote:
Originally Posted by YR4Dude View Post
Actually you want it to roll more. To do so you will need to increase droop and lower you're roll center.

When you're car traction rolls, its because there are forces pushing on the car to rotate on its outside wheel as it turns. If the car doesn't roll and the forces are great, the car will pivot on the outside tire lifting the inside tire. The inside tire lifts because there's not enough droop to maintain contact with the surface. Hence the need to add droop. To prevent the forces from pushing hard enough to pivot your car on the outside wheel, you need to make the car roll more. The rolling action sucks up that force which would otherwise pivot your car at the wheel if it didn't roll.
I also think you need to soften the car up. Maybe reduce your sway bars and or spring rate. This works for me.
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Old 05-02-2011, 06:08 PM   #9
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In the past I've found softening springs ets helped.

Also;
Superglue sidwall of tyres
Check tyres are still properly glued to the rims
High front roll centre (Wishbone pivots)
Increase front track width at the wishbones to 2.25mm etc

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Old 05-02-2011, 06:29 PM   #10
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Quote:
Originally Posted by YR4Dude View Post
Actually you want it to roll more. To do so you will need to increase droop and lower you're roll center.

When you're car traction rolls, its because there are forces pushing on the car to rotate on its outside wheel as it turns. If the car doesn't roll and the forces are great, the car will pivot on the outside tire lifting the inside tire. The inside tire lifts because there's not enough droop to maintain contact with the surface. Hence the need to add droop. To prevent the forces from pushing hard enough to pivot your car on the outside wheel, you need to make the car roll more. The rolling action sucks up that force which would otherwise pivot your car at the wheel if it didn't roll.
When you're car traction rolls, its because there are forces pushing on the car to rotate on its outside wheel as it turns. If the car doesn't roll and the forces are great, the car will pivot on the outside tire lifting the inside tire.

If the car does not "roll" it will slide, not flip over, the chassis is stiff. Everything you just said gives the car more grip, it has grip, it's fliping over. Stiffer bars take traction away, stiffer springs take traction away, super glue takes traction away. less droop takes traction away.

The rolling action sucks up that force which would otherwise pivot your car at the wheel if it didn't roll.

Stiffing up the car takes away the "rolling action" that is fliping your car over, it will piviot, if the rear is to stiff it will spin out, if the rear is to soft the car will flip over off the outside rear tire thru a turn. If the front of the car is to stiff, it will have understeer. If it is to soft it will flip over off the outside front tire.

Idealy, you would like the car to flip over right thru the middle, or say thru a high speed sweeper, both inside tires lift off the gound, at the least the chassis is balanced front and rear, Super glue is the fix here. If you want to dig into the setup, on this car that I just talked about, (the netural fliping car) heavier oil is a start, or stiffer front and rear bars. In all honesty, at this point I like super glue because I retain the steering about 95% of it at least, and the car pushes, and a pushing car is very easy to drive. It is the safest plan of action in a tight fix.

Rolling is good, but it needs to be limited, flipping over is to much rolling

Rolling "action" amplyfies the force. A stiffer bar pushes the inside wheel back down, it takes the "rolling action" and puts it back to the inside tire. Same in the rear.

Dude who started this thread, save yourself the problems, super glue the tires, the car WILL PUSH, you can retune from there if you feel it is nessary. Also if your car was dialed before the grip came up, you had to much steering, or traction. You want a car that pushes in low grip, as grip comes up the car turns more.

Ever been to a race where the fastest guy in pratice is out to lunch with an undrivable car once the track gets gripy? He has to much steering, the car will turn on a dime....or flip over....

I am willing to bet your setup is not that bad, and Superglue will make your life alot easier....try it....

Also, High roll centers will help if you feel it nessary, and make sure you are at the max on front and rear track width.
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Last edited by chubbspeterson; 05-02-2011 at 06:42 PM.
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Old 05-02-2011, 06:39 PM   #11
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http://www.rctech.net/forum/6723326-post32.html
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Old 05-02-2011, 06:42 PM   #12
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Quote:
Originally Posted by jammincrtjames View Post
Glue the front side walls. No more traction roll.
How much of the sidewall do you glue on rubber tires?
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Old 05-02-2011, 06:48 PM   #13
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Quote:
Originally Posted by JoelV View Post
So I am hearing that softening your car to the point you have no suspension will stop the car from flipping over?

And that on carpet, where all my knowlage comes from, you can never break traction?

WOW....news to me, all the cars I see spinning out must have some serious issues.......

In the whole post the only thing I like is the less caster....why less caster?
Oh thats right is makes for a less steering....huh? who knew....
Also less camber, why?
Oh, it makes the contact patch smaller, hum whats that do? Breaks traction? why whould you do that? oh to stop it from flipping over....got it.

Also, it states that whoever this is goes to stiffer front dampening....very good, resisting the "roll"
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Last edited by chubbspeterson; 05-02-2011 at 06:58 PM.
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Old 05-02-2011, 06:53 PM   #14
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You know where the "superglue trick" comes from?

It comes from when you have a setup that has to much steering, and everything you undo makes the car have to little steering. Basicly if the car stayed on 4 wheels, it would have crazy corner speed, and turn like crazy. when I tune out the steering, the car has to much understeer, and I'm off pace.

Overseas, these guys would put the superglue on, because they wanted to keep the steering without the traction rolling, so stiffing the sidewall does not let the rubber fold over and contunie to have traction. the stiff side wall breaks traction...you slide....
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Old 05-02-2011, 08:27 PM   #15
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The simple solution to traction roll is to raise your roll center (yes RAISE). This will decrease your roll and decrease your grip. You can try this on either the front or the rear or both simply by lowering your upper link inside attachment so that you have more of an angle between the upper link and the lower arm. Some of the other things that were mentioned will work also
(stiffer springs, roll bars, and glue on the sidewall to decrease flex, etc.)
but the simple fix is the roll center.
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