Tune With Camber Links
#274
#276
Tech Champion

Joined: Oct 2007
Posts: 7,342
Talking about weight transfer is always tricky, as it can be somewhat counterintuitive.
When one reduces the roll stiffness on a given end of the car, that end, and thus the entire chassis, tends to roll/lean more. Many times this will be described as increased weight transfer (change in vertical forces on the tires). But in reality it is less, due to the reduced roll stiffness the other end of the car is taking more of the roll loads.
Roll forces on a given end won't be higher with less roll stiffness, they will be lower. The other end of the car sees the higher roll loads/weight transfer, as that roll stiffness has not changed, but is now a larger portion of the overall chassis roll stiffness.
When one reduces the roll stiffness on a given end of the car, that end, and thus the entire chassis, tends to roll/lean more. Many times this will be described as increased weight transfer (change in vertical forces on the tires). But in reality it is less, due to the reduced roll stiffness the other end of the car is taking more of the roll loads.
Roll forces on a given end won't be higher with less roll stiffness, they will be lower. The other end of the car sees the higher roll loads/weight transfer, as that roll stiffness has not changed, but is now a larger portion of the overall chassis roll stiffness.
#277
#278
Joined: Mar 2011
Posts: 2,766
From: Houston
You are using their resistance to aid in roll stiffness. If they move around a little bit without twisting as the suspension moves, you have decreased their effectiveness. You may end up bending the bars a little bit before they start to twist. A little play might not hurt but you want them as tight as they can get yet still be free moving. You shouldn't be able to move them left or right but they shouldn't bind either. If there is nothing connected to them they should just fall down on their own just from the force of gravity but they shouldn't be so loose that they have slop in their mounting.
#279
You are using their resistance to aid in roll stiffness. If they move around a little bit without twisting as the suspension moves, you have decreased their effectiveness. You may end up bending the bars a little bit before they start to twist. A little play might not hurt but you want them as tight as they can get yet still be free moving. You shouldn't be able to move them left or right but they shouldn't bind either. If there is nothing connected to them they should just fall down on their own just from the force of gravity but they shouldn't be so loose that they have slop in their mounting.
There are many racers with them setup wrong
#280
Tech Regular
iTrader: (7)
Joined: Feb 2011
Posts: 313
Went to wcrc today and got to test and tune my suspension some more. my shocks worked o.k., but need some more dialing in. I am going to go with some 2 stage pistons as my 2wd slash with the rpm 2 stagers work much better than my d8's with single stage on my 4wd slash do.
Anyway, my truck worked pretty good handling wise, but I was having issues with the back end breaking loose unpredictably at the end of the long straight going into a left hand 90 turn. I decided to try moving the inner rear camber links down to give it more of a predictable sliding feel and it worked out pretty good.
The trade off(there always is one) is that it took some getting used to on other parts of the track and I was actually slower around the track except for the one turn at the end of the straight. looks like i need to spend some more time fine tuning it.
Anyway, my truck worked pretty good handling wise, but I was having issues with the back end breaking loose unpredictably at the end of the long straight going into a left hand 90 turn. I decided to try moving the inner rear camber links down to give it more of a predictable sliding feel and it worked out pretty good.
The trade off(there always is one) is that it took some getting used to on other parts of the track and I was actually slower around the track except for the one turn at the end of the straight. looks like i need to spend some more time fine tuning it.
#281
Tech Fanatic
iTrader: (22)
Joined: Oct 2003
Posts: 814
From: downunder
Let's start with how it handles coming out of a corner. Let's say under hard throttle out of a corner the inside front wheel lifts off the ground and you get severe under steer. Most people would be tempted to stiffen the rear springs. Don't do this! You do need more roll stiffness though so start raising your roll centers. I prefer to keep the links level at level ride height so I'd start shortening the links. Keep testing out of a corner. Does the problem fix itself or does the wheel keep coming up? Can you lower the front roll center? Can you make the front link longer? This will reduce some front roll stiffness allowing the front to roll more. You want all 4 wheels on the ground in a corner!
If you can not get to where you need to be upon entry to a corner, why would you even consider contemplating about tunning for corner exit!
Not where you need to be on entry you have no chance of being where you need to be on exit!
#282
There is merit in your methods, however I see very little point in starting your tunning coming out of a corner.
If you can not get to where you need to be upon entry to a corner, why would you even consider contemplating about tunning for corner exit!
Not where you need to be on entry you have no chance of being where you need to be on exit!
If you can not get to where you need to be upon entry to a corner, why would you even consider contemplating about tunning for corner exit!
Not where you need to be on entry you have no chance of being where you need to be on exit!
#283
Joined: Mar 2011
Posts: 2,766
From: Houston
What if we have severe understeer going into a corner but severe oversteer coming out of it? Where do you start? What if we have severe oversteer going into a corner but severe understeer coming out? Where do you start? I'm sure the obvious answer that someone is going to say is with caster blocks but what if they don't fix your problem? What then? What happens if you get a decent compromise this way but then induce bump steer which lowers stability in other places? Keep in mind not all vehicles have the same amount of tuneability and as such may be more prone to handling compromise than others.
The point I keep trying to get across over and over again is doing things in a systematic fashion. One thing at a time. Don't overthink the scenario and try to fix everything at once. I can't list every single scenario. All I can do is give a few examples and hopefully everyone can figure out the rest from there. That's the whole point. If you want to tackle issues in a different order than my examples then go ahead. Just make one change at a time.
The point I keep trying to get across over and over again is doing things in a systematic fashion. One thing at a time. Don't overthink the scenario and try to fix everything at once. I can't list every single scenario. All I can do is give a few examples and hopefully everyone can figure out the rest from there. That's the whole point. If you want to tackle issues in a different order than my examples then go ahead. Just make one change at a time.
#284
Went to wcrc today and got to test and tune my suspension some more. my shocks worked o.k., but need some more dialing in. I am going to go with some 2 stage pistons as my 2wd slash with the rpm 2 stagers work much better than my d8's with single stage on my 4wd slash do.
Anyway, my truck worked pretty good handling wise, but I was having issues with the back end breaking loose unpredictably at the end of the long straight going into a left hand 90 turn. I decided to try moving the inner rear camber links down to give it more of a predictable sliding feel and it worked out pretty good.
The trade off(there always is one) is that it took some getting used to on other parts of the track and I was actually slower around the track except for the one turn at the end of the straight. looks like i need to spend some more time fine tuning it.
Anyway, my truck worked pretty good handling wise, but I was having issues with the back end breaking loose unpredictably at the end of the long straight going into a left hand 90 turn. I decided to try moving the inner rear camber links down to give it more of a predictable sliding feel and it worked out pretty good.
The trade off(there always is one) is that it took some getting used to on other parts of the track and I was actually slower around the track except for the one turn at the end of the straight. looks like i need to spend some more time fine tuning it.
#285
Joined: Mar 2011
Posts: 2,766
From: Houston
By lowering the inner rear camber links, the roll center was raised a little bit in the rear. It should lose the rear end a bit worse going into corners. Marcus is right. Put it back. You've just got too much weight transfer to the front during braking.



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