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Tune With Camber Links

Old 11-11-2014, 11:36 AM
  #1936  
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Haha...your car won't explode if it isn't tuned exactly to the method mentioned early on in this thread. You can't "fail". The intention was to get the shocks setup to do what they are supposed to do: handle bumps and jumps. Once you find bump/jump handling balance you SHOULD be able to tune the corner handling of the car/truck with camber link and sway bar adjustments (and all the other crazy adjustments we have at our disposal now). I think what most people will find is that if they focus on finding that initial balance, the other adjustments seem to give better results and finer granularity. All that being said, tuning is a personal thing. There is no "right" or "wrong". The key is to make your car faster and more consistent and win races. Whatever method you need to make that happen is the key.
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Old 11-11-2014, 03:55 PM
  #1937  
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Originally Posted by rcgerber View Post
Raising the outer link (on the hub) will raise the roll center. I've found it will generally add more rear traction.
http://www.thecartech.com/subjects/a...oll_Center.htm

http://users.telenet.be/elvo/

http://jtprc.com/2013/12/29/setup-tip-roll-center/
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Old 11-11-2014, 04:20 PM
  #1938  
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When you read Jared Tebo's article on roll-center - it's nice to hear that even the pros don't always know "everything" about the adjustments on the car. Fortunately for them, they just naturally wheel the car faster than the rest of us... I think Jared is a real class act.
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Old 11-12-2014, 08:23 AM
  #1939  
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Originally Posted by rcgerber View Post
Raising the outer link (on the hub) will raise the roll center. I've found it will generally add more rear traction.
If your starting out with a car that has generally very low RC, then your statement of raising RC will add more traction would be true. Otherwise its compeletly dependant on the track surface traction.

On high bite tracks it will make the car respond faster than the driver can react to it. Hence edgy, touchy, squirly.

It depends on the surface

High traction track generally prefers lower RC
Loamy low traction prefers higher RC
Dusty low traction prefers sacrifice, softer balanced springs with slightly higher RC to limit excessive body roll.
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Old 11-12-2014, 11:21 AM
  #1940  
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Originally Posted by b3master View Post
High traction track generally prefers lower RC
Loamy low traction prefers higher RC
Dusty low traction prefers sacrifice, softer balanced springs with slightly higher RC to limit excessive body roll.
b3master, I thought I had a good handle on roll center but you just confused me again

I had understood the effect on roll center, particularly rear RC, as opposite as to what you just posted. I.e. lower rear roll center= more roll and that is BETTER in low traction conditions.

My understanding and reasoning is as follows:

During a curve, you maintain the best traction by maintaining pressure on both inside and outside tires as long as possible. When all weight gets suddenly transferred to the outside tire, you have less overall traction than if both rear tires were gripping). By slowing down weight transfer from inside to outside you get to smooth out this transfer and maintain pressure on both rear tires for longer.

On high traction tracks, we are not as concerned with maximizing traction since there is plenty of it, and we can raise RC to have less chassis roll and take advantage of a more responsive car.

Does this make sense to anyone else or do I really have it all wrong???

Note that I had come to this understanding based on reading-up a lot on this issue, including different books on (full scale) auto racing, several articles and websites such as this one: http://www.thecartech.com/subjects/a...oll_Center.htm which states:

"Effects of Front Roll Center Adjustment

Front roll center has most effect on on-throttle steering during mid-corner and corner exit.

LOWER front roll center
* More on-throttle steering
* Car is less responsive
* Better on smooth, high grip tracks with long fast corners

HIGHER front roll center
* Less on-throttle steering
* Car is more responsive
* Use in high grip conditions to avoid traction rolling
* Use on tracks with quick direction changes (chicanes)"
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Old 11-12-2014, 01:12 PM
  #1941  
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Originally Posted by b3master View Post
If your starting out with a car that has generally very low RC, then your statement of raising RC will add more traction would be true. Otherwise its compeletly dependant on the track surface traction.

On high bite tracks it will make the car respond faster than the driver can react to it. Hence edgy, touchy, squirly.

It depends on the surface

High traction track generally prefers lower RC
Loamy low traction prefers higher RC
Dusty low traction prefers sacrifice, softer balanced springs with slightly higher RC to limit excessive body roll.
b3 what you wrote just matches what I said just with more detail. Low traction tracks like a higher rear roll center because it adds more rear traction.
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Old 11-12-2014, 01:16 PM
  #1942  
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Wow a lot of wrong stuff in this thread lately

In general

Low roll center = more body roll = more traction

High roll center = less body roll = less traction


Either people are confusing roll center height with cg height or people are confused with what raising or lowering ball stud height inboard and outboard actually does.
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Old 11-12-2014, 02:15 PM
  #1943  
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Originally Posted by stelio279 View Post
b3master, I thought I had a good handle on roll center but you just confused me again

I had understood the effect on roll center, particularly rear RC, as opposite as to what you just posted. I.e. lower rear roll center= more roll and that is BETTER in low traction conditions.

My understanding and reasoning is as follows:

During a curve, you maintain the best traction by maintaining pressure on both inside and outside tires as long as possible. When all weight gets suddenly transferred to the outside tire, you have less overall traction than if both rear tires were gripping). By slowing down weight transfer from inside to outside you get to smooth out this transfer and maintain pressure on both rear tires for longer.

On high traction tracks, we are not as concerned with maximizing traction since there is plenty of it, and we can raise RC to have less chassis roll and take advantage of a more responsive car.

Does this make sense to anyone else or do I really have it all wrong???

Note that I had come to this understanding based on reading-up a lot on this issue, including different books on (full scale) auto racing, several articles and websites such as this one: http://www.thecartech.com/subjects/a...oll_Center.htm which states:

"Effects of Front Roll Center Adjustment

Front roll center has most effect on on-throttle steering during mid-corner and corner exit.

LOWER front roll center
* More on-throttle steering
* Car is less responsive
* Better on smooth, high grip tracks with long fast corners

HIGHER front roll center
* Less on-throttle steering
* Car is more responsive
* Use in high grip conditions to avoid traction rolling
* Use on tracks with quick direction changes (chicanes)"
You still have a great understanding on front and rear RC. Its all relative.
Methods described in this thread, once read entirely, cause racers to think independently to what they have heard or seen.
I didnt want other racers to blindly follow a statement such as "Raising the outer link (on the hub) will raise the roll center and will generally add more rear traction" simply because it isnt 100% true, not 100% of the time. It totally depends on what type of surface we are running on, and relative to setup starting point.

For sandy, loamy, flaky, natural and not packed surfaces its true. because you want enough pressure to dig into the surface, and having weight spread on to both tires doesnt cause enough pressure. hence its preferred to raise the RC and cause the outer tire to have more of the weight transferred to it so it can have higher pressure and bite in better to respond to directional change.
Not to mention sandy and loamy surfaces are usually bumpy and one would prefer a soft plush suspension and then counteract the excessive body roll caused by the softer suspension with a higher RC.

ON dry dusty low traction surface (still depends on other variables as well*) there usually isnt enough pressure from the tires to the surface to cause the ideal body roll and weight transfer, its preferred to soften up the suspension (keeping balance) and then deal with RC depending on the result of the softer suspension. This doesnt take into account ruts, bumps, track imperfection. Once again like mentioned several times previously in the thread you want to set up the car to 80% of the track and deal with the remaining 20%.

I believe that each car and its unique weight distribution has an ideal body roll angle. Depending on the traction you will want to adjust RC to cause that maximum roll angle, not more, not less. Generally, dry hard low traction surfaces you will usually break lose before reaching the ideal angle. on high traction you most probably would exceed the idea body roll and cause traction rolls and instability.

If RC is too low (generally lets say wrt stock setup*) it will cause excessive body roll, hence traction rolls on high track surfaces.
It will cause not enough tire pressure on low traction surfaces causing car to skid sideways excessively losing precious time at every corner. If front and rear RC are not equal it will cause push or spin out on low traction surfaces.

Conclusion dont change your understanding on RC, but also dont follow straight blind rules like "lower rc more traction" cause it isnt true.
There is balance to everything. In-to-corner, mid-corner, and out-of-corner traction are some to think of.

* Statements are greatly dependent on which car is being discussed and what is the starting setup point. This is why Fred's way to finding complete balance is ideal, You find the balance and THEN go from there. spring balance, piston and shock oil balance, Plush and pack balance, front to rear RC balance, in-to mid and out-of corner steering balance. Once balance is achieved THEN we can properly discuss and say lower or higher RC, it will be relative and based on your ideal balanced setup.

Let me summarize it in a different way:
**its all relative, to one car and its starting setup a higher RC might add traction to another car and its starting setup a higher RC might decrease traction.
***On one surface a lower RC will increase traction on another surface it will decrease traction.

Dont follow direct rules blindly. Im not trying to purposely confuse the some of you. I just want yall to think for yourselves for your particular track and surface and your setup's starting point. In the end I hope I made you understand clearer how its all relative.
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Old 11-12-2014, 02:35 PM
  #1944  
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I just thought of another small example to think of.

We all want more grip, we all want traction, with more traction we can achieve faster lap times.

Ever wondered if lower RC always achieved more traction, then why dont all manufacturers just lower the RC as much as possible? Then we can all go race with max traction.
That is because there is a LIMIT and balance to everything. If you EXCEED ideal rear RC the car will just drift into corners excessively if its too low; and it will drift or spin out effortlessly if its too high. If the front RC is too low or too high it will PUSH.
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Old 11-12-2014, 02:50 PM
  #1945  
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Originally Posted by b3master View Post
I just thought of another small example to think of.

We all want more grip, we all want traction, with more traction we can achieve faster lap times.

Ever wondered if lower RC always achieved more traction, then why dont all manufacturers just lower the RC as much as possible? Then we can all go race with max traction.
That is because there is a LIMIT and balance to everything. If you EXCEED ideal rear RC the car will just drift into corners excessively if its too low; and it will drift or spin out effortlessly if its too high. If the front RC is too low or too high it will PUSH.
I was going to post this, but you beat me too it. My version was, "if more body roll always equals more traction, why don't we set up our chassis to go completely vertical while going around a turn?" An absurd situation like that always helps to make the point.
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Old 11-12-2014, 02:55 PM
  #1946  
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To add examples from the confusion:

During a curve, you maintain the best traction by maintaining pressure on both inside and outside tires as long as possible. When all weight gets suddenly transferred to the outside tire, you have less overall traction than if both rear tires were gripping). By slowing down weight transfer from inside to outside you get to smooth out this transfer and maintain pressure on both rear tires for longer.
That is true for HIGH traction surfaces because you want smooth transition into and out of corners and less twitchy less responsive car. However this is false to loamy tracks because it will cause an unresponsive car.

On high traction tracks, we are not as concerned with maximizing traction since there is plenty of it, and we can raise RC to have less chassis roll and take advantage of a more responsive car.
This is False, because high traction track within itself already causes very responsive car, you want to minimize response and smooth out the reaction. However its True that a higher RC can help decrease traction rolls but it also helps car become excessively responsive, unstable, and twitchy.

I was going to post this, but you beat me too it. My version was, "if more body roll always equals more traction, why don't we set up our chassis to go completely vertical while going around a turn?" An absurd situation like that always helps to make the point.
Right on!

There are Limits to everything.
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Old 11-12-2014, 03:28 PM
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in general this thread has helped me and confused me... helped cause it gave me the courage to start playing with camber ... confused me cause I just cant get it ...

I have my MM buggy and MM sct turning well except one spot. mid corner the rear just comes out. usually only at end of straight and 90deg turn. should I lower the inside or raise it. should the hub side be low or high?
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Old 11-12-2014, 03:40 PM
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Originally Posted by Dizzyka View Post
in general this thread has helped me and confused me... helped cause it gave me the courage to start playing with camber ... confused me cause I just cant get it ...

I have my MM buggy and MM sct turning well except one spot. mid corner the rear just comes out. usually only at end of straight and 90deg turn. should I lower the inside or raise it. should the hub side be low or high?
My advice is to leave everything alone since its just that one part of the track and deal with it by adapting your driving to that situation. I advise you to adjust your throttle curve to be more in the negative, try -10% to -20% throttle curve. that will smooth out your throttle as your exiting the turn.

As for the confusion, just reread some main parts of the thread and it will become clear. It never sinks in the first time.
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Old 11-12-2014, 04:17 PM
  #1949  
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My advice would normally match B3Masters but if you are looking to just try some tuning for learning purposes, I think you will find that if you raise the ball stud, the chassis will roll a little more and you will get traction in that corner. However, this will require the chassis to roll further to make traction. You might find that in the rest of the track the rear end feels a bit wallowy and greasy. For example, getting on throttle coming out of a corner onto a straight, it may feel like you have actually lost a bit of traction because the chassis isn't resisting the roll as quickly and one tire or the other starts to spin.
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Old 11-12-2014, 08:52 PM
  #1950  
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For me, I try to look at the mounting hole and their relationship (distance) to the hinge point. Then its easier to see how much LEVERAGE a certain hole would gain or loose.
If you start at the shock tower mount, then go to the upper hub mount, then to lower hub hinge. then you can see how the upper camber link has leverage on the hub and transfering this to the tire.
Try and picture the chassis roll into the camber link and tranfer that leverage into the hub.

This is just how I look at it, hope it helps others

I understand that the fourth, lower inner hinge has to be taken into consideration, especially during compression as to the total amount of leverage.
Ride height also has a big play with chassis roll.

But mainly like b3master was saying, the track determines how to best apply your leverage
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