SC10 Thread
01-04-2010 | 04:43 PM
#3751
Tech Champion
Joined: Apr 2008
Posts: 6,027
From: Columbus, OH
Theres another dynamic to weight transfer.
The car floats on its springs and shock oil. You don't start to hook up until the weight is transfered onto the outside spring. The oil slows this down. So a lighter oil will quicken weight transfer.
So for ultimate traction light oils can really help. Lighter springs will allow more weight transfer forwards and backwards, but roll too much. The Sway bar helps control the excessive roll.
Keep in mind that the body on a Sc10 can weigh around 225grams and is 6" off the ground. I can get a decent lipo that heavy! The truck has excessive roll when useing softer springs for slippery tracks and this can ruin rear traction. At least run the black sway bar.
Also the sway bar counts as spring so your weight transfer during cornering will "hit" sooner like haveing stiffer springs or lighter oil. All a sway bar deos is take the force of the inside shock spring that is fully extended, as much force as the thickness of the bar allows before bending, and adds that force to the compressed outside spring. If you removed your inside shock springs the sway bar would do nothing.
Most racers would benifit from a "soft spring, stiff bar" setup. Using the stock #3 and #1 pistons. A setup that I'm useing that requires about 1/2 an once added to the nose and none to the rear. Very light, which helps landing jumps.
The Sc10 has a ton of pack and suspension travel, yet can be setup alot softer than the blitz and slash.
The car floats on its springs and shock oil. You don't start to hook up until the weight is transfered onto the outside spring. The oil slows this down. So a lighter oil will quicken weight transfer.
So for ultimate traction light oils can really help. Lighter springs will allow more weight transfer forwards and backwards, but roll too much. The Sway bar helps control the excessive roll.
Keep in mind that the body on a Sc10 can weigh around 225grams and is 6" off the ground. I can get a decent lipo that heavy! The truck has excessive roll when useing softer springs for slippery tracks and this can ruin rear traction. At least run the black sway bar.
Also the sway bar counts as spring so your weight transfer during cornering will "hit" sooner like haveing stiffer springs or lighter oil. All a sway bar deos is take the force of the inside shock spring that is fully extended, as much force as the thickness of the bar allows before bending, and adds that force to the compressed outside spring. If you removed your inside shock springs the sway bar would do nothing.
Most racers would benifit from a "soft spring, stiff bar" setup. Using the stock #3 and #1 pistons. A setup that I'm useing that requires about 1/2 an once added to the nose and none to the rear. Very light, which helps landing jumps.
The Sc10 has a ton of pack and suspension travel, yet can be setup alot softer than the blitz and slash.
01-04-2010 | 05:16 PM
#3754
All a sway bar deos is take the force of the inside shock spring that is fully extended, as much force as the thickness of the bar allows before bending, and adds that force to the compressed outside spring. If you removed your inside shock springs the sway bar would do nothing.
01-04-2010 | 05:26 PM
#3755
Traction is the friction a tire can generate, to overcome this weight must be applied. You have side and forward force vectors to this. If we are steady state through a corner a roll bar will apply more pressure to the outside tire sooner in the stroke and that load is what gives less side grip in a corner.
01-04-2010 | 05:34 PM
#3757
Joined: Jan 2006
Posts: 3,520
From: Lost in the Dead Space between my Ears Somewhere around Wamego, KS (OZ Land)
Anti-Roll bar
Anti-roll bars are best used on smooth, and high-traction tracks only.
If you must use one on a bumpy track, try to use a very thin one.
Adding an anti-roll bar, or stiffening it, reduces traction at that end of the car. So it feels like the opposite end has more grip.
If the track is smooth enough, it also makes the grip level feel more consistent.
Anti-roll bars reduce body roll in turns, so they make the car feel more direct, and make it change direction quicker.
Stiffer Front
An anti-roll bar at the front of the car reduces low-speed steering. The turning radius will
be larger, but very consistent.
It reduces 'hooking' by preventing front end roll.
The car will have more rear traction in turns.
Stiffer Rear
Adding an anti-roll bar to the rear of the car gives more steering. the car steers tighter,
also at low speeds.
On a very smooth track, it can make powersliding easier. It can also make powering out
of turns and lining up for jumps a little easier.If you must use one on a bumpy track, try to use a very thin one.
Adding an anti-roll bar, or stiffening it, reduces traction at that end of the car. So it feels like the opposite end has more grip.
If the track is smooth enough, it also makes the grip level feel more consistent.
Anti-roll bars reduce body roll in turns, so they make the car feel more direct, and make it change direction quicker.
Stiffer Front
An anti-roll bar at the front of the car reduces low-speed steering. The turning radius will
be larger, but very consistent.
It reduces 'hooking' by preventing front end roll.
The car will have more rear traction in turns.
Stiffer Rear
Adding an anti-roll bar to the rear of the car gives more steering. the car steers tighter,
also at low speeds.
On a very smooth track, it can make powersliding easier. It can also make powering out
01-04-2010 | 05:49 PM
#3759
Joined: Jan 2006
Posts: 3,520
From: Lost in the Dead Space between my Ears Somewhere around Wamego, KS (OZ Land)
Its part of my rc bible. It has a link if I could find it.
Try this.
http://home.scarlet.be/~be067749/58/
Try this.
http://home.scarlet.be/~be067749/58/
01-04-2010 | 06:36 PM
#3760
01-04-2010 | 06:40 PM
#3761
Joined: Jan 2006
Posts: 3,520
From: Lost in the Dead Space between my Ears Somewhere around Wamego, KS (OZ Land)
01-04-2010 | 06:45 PM
#3762
I go off of this description from the general suspension section of scarlet.be
Originally Posted by Scarlet.be
Anti-roll bars are like 'sideways springs', they only work laterally. Here's how they work: if one side of the suspension is compressed, one end of the bar is lifted. The other end will also go up, pulling the other side of the suspension up also, basically giving more resistance to chassis roll. How far and how strongly the other side will be pulled up depends on the stiffness and the thickness of the bar used: a thin bar will flex a lot, so it won't pull the other side up very far, letting the chassis roll deeply into its suspension travel. Note that the bar only works when one side of the suspension is extended further than the other, like when the car is cornering. When both sides are equally far compressed, like when the car is braking, the bar has no effect. So anti-roll bars only affect the lateral balance of the car, not the longitudinal balance.
Unfortunately, anti-roll bars aren't the only things affecting the car's roll stiffness; they work in conjunction with the springs and dampers. Suppose you add an anti-roll bar at the rear of your car without changing any of the other settings. When the car enters a turn, the chassis starts to roll. Normally, the suspension on the outside of the turn would compress, and the one on the inside would extend, making for a lot more pressure on the outside tire. With the anti-roll bar however, the suspension on the inside will be compressed, so the chassis will roll less, and the rear of the car will sit lower than normal. So the rear has more weight on it, and it's distributed more evenly over the two tires. This makes for a little more, and more consistent traction. Remember that this is in the beginning of the turn, the situation is different in the middle of the turn. Normally, without the anti-roll bar, the chassis would stop rolling when the roll torque is fully absorbed by the outsid e spring. But with the anti-roll bar, some of that torque is absorbed by the anti-roll bar, and used to compress the inside suspension. So the outside suspension won't be compressed as much as it normally would, making the rear of the chassis sit up higher than normal, so less weight is on the rear of the car, and more at on the front. It's as if suddenly the rear has become stiffer, making for more steering and a little less rear traction. Rear traction is more consistent however, because the weight is distributed more evenly over the rear tires, unless the track is really bumpy, that is; anti-roll bars can really mess up a car's rough track handling, so they're rarely used on bumpy tracks. Adding an anti-roll bar at the front of the car has a similar, but opposite effect: it decreases steering, but makes it much smoother and more consistent. It can stop the front from 'biting into' the surface too much, making the turning radius big and smooth. This can come in handy on large, wide tracks.
Math-wise, the torsion stiffness of the middle part of the bar goes up with the fourth power of the bar's diameter, and for the two side parts, torsion stiffness goes up with the square of the diameter. Keep this in mind while changing anti-roll bars.
Unfortunately, anti-roll bars aren't the only things affecting the car's roll stiffness; they work in conjunction with the springs and dampers. Suppose you add an anti-roll bar at the rear of your car without changing any of the other settings. When the car enters a turn, the chassis starts to roll. Normally, the suspension on the outside of the turn would compress, and the one on the inside would extend, making for a lot more pressure on the outside tire. With the anti-roll bar however, the suspension on the inside will be compressed, so the chassis will roll less, and the rear of the car will sit lower than normal. So the rear has more weight on it, and it's distributed more evenly over the two tires. This makes for a little more, and more consistent traction. Remember that this is in the beginning of the turn, the situation is different in the middle of the turn. Normally, without the anti-roll bar, the chassis would stop rolling when the roll torque is fully absorbed by the outsid e spring. But with the anti-roll bar, some of that torque is absorbed by the anti-roll bar, and used to compress the inside suspension. So the outside suspension won't be compressed as much as it normally would, making the rear of the chassis sit up higher than normal, so less weight is on the rear of the car, and more at on the front. It's as if suddenly the rear has become stiffer, making for more steering and a little less rear traction. Rear traction is more consistent however, because the weight is distributed more evenly over the rear tires, unless the track is really bumpy, that is; anti-roll bars can really mess up a car's rough track handling, so they're rarely used on bumpy tracks. Adding an anti-roll bar at the front of the car has a similar, but opposite effect: it decreases steering, but makes it much smoother and more consistent. It can stop the front from 'biting into' the surface too much, making the turning radius big and smooth. This can come in handy on large, wide tracks.
Math-wise, the torsion stiffness of the middle part of the bar goes up with the fourth power of the bar's diameter, and for the two side parts, torsion stiffness goes up with the square of the diameter. Keep this in mind while changing anti-roll bars.
01-04-2010 | 07:05 PM
#3763
I read through something like that and get to one spot and say WHAT?
In that he says that to keep the body roll down the roll bar is transferring spring from the inside to the outside, holding the inside up and keeping the outside from moving up. OK, got it, so now how does weight get transferred back to inside when the lateral acceleration is throwing it to the outside? Short answer is it doesn't, while every other thing about the sway bars is true it simply can't put weight on the inside tire. In fact it's working to pick the inside tire UP.
In that he says that to keep the body roll down the roll bar is transferring spring from the inside to the outside, holding the inside up and keeping the outside from moving up. OK, got it, so now how does weight get transferred back to inside when the lateral acceleration is throwing it to the outside? Short answer is it doesn't, while every other thing about the sway bars is true it simply can't put weight on the inside tire. In fact it's working to pick the inside tire UP.
01-04-2010 | 07:15 PM
#3764
i do not read where it says that. please quote area that says that. highlight and copy sentence, hit the quote tool, paste between quote tags
01-04-2010 | 07:54 PM
#3765
To me this sums up our disagreement. I just think in a completely different way.
Traction is the friction a tire can generate, to overcome this weight must be applied. You have side and forward force vectors to this. If we are steady state through a corner a roll bar will apply more pressure to the outside tire sooner in the stroke and that load is what gives less side grip in a corner.
Traction is the friction a tire can generate, to overcome this weight must be applied. You have side and forward force vectors to this. If we are steady state through a corner a roll bar will apply more pressure to the outside tire sooner in the stroke and that load is what gives less side grip in a corner.
Also sway bars can upset the chassis on a very bumpy track. If your track has a lot of bumps and pot holes, a stiff bar can transfer too much spring rate to the side of the car hitting the bump and pitch the chassis up on that side of the car. If you have no bar or a very light one, the chassis will stay flatter and let the suspention do it's job. It's all a trade off you have to test, test, test and figure out what works best for your driving style
. I'm out.