Bri

I am seeing conflicting info on rear camber. Looking for what is correct for a 2wd SCT.

The XXXMain setup guide says more rear negative camber gives more rear grip which would help a loose rear end.

The XRay XB2 and Tekno set up guide says more rear negative camber decreases rear traction entering and in the corners.

Does anyone know which is correct?

Best regards,
Brian

30Tooth

iTrader: (1)

Neither.

The assumption of a change depends on which state your car is right now. If the car needs more or less camber for example, depends if you have too much or too less of it. Either way, 1* of negative camber is a good start, then the critical part is dynamic camber as the suspension is always cycling. The more the tire is kept around that 1* (camber varies with tire and wheel requirements) with roll and pitch/yaw motions the better the tire will perform, that is changed by upper link length and position.

Hope it helps!

a1

iTrader: (9)

30Tooth

iTrader: (1)

Being that I have experience doing this I can say two things. Try a shorter upper arm with 1* of camber on the rear, most 1/10th platforms lack dynamic camber.

billdelong

iTrader: (33)

Pretty good guide here worth a read:
http://www.teknorc.com/wp-content/up...t_Up_Guide.pdf

Bri

First it says "Generally more negative camber means increased grip in the corners" but under rear camber, it says "more negative camber = Decreases traction entering and while cornering".

The reference to the caster also seems to contradict itself. In the first paragraph it says "High caster angles (more inclined) require less negative camber". Then in the second paragraph, it says "a steeper caster angle requires more camber".

Can anyone make sense of what they mean?

Best regards,
Brian

billdelong

iTrader: (33)

Here's another chart provided by Hudy, take note of whether you want to increase or decrease the camber based on what you need your steering response to do:

Full Size Chart


Try to think of camber as starting at -2° for a general starting point for most cars both front and rear. When tuning you don't really want to go any farther than 2° in either direction from your starting point in either the front or the rear. I find that tuning changes to the front tend to be significantly less aggressive than changes made to the rear.

So for example, let's say my car is spinning out of control in turns (need to correct over steer) and I'm focusing only on camber in this example to make adjustments, then I would first start with the front end by setting it to -1° and if that didn't do the trick then I might go to 0°. Now lets say that still wasn't enough.... then I might bump the rear to -3°... but now lets say that change was too much and now the car is starting to push (under steer), then I'd bump the front to -1° again and that might be the sweet spot for the given track conditions and tire combination, etc...

I'm over simplifying things, but just trying my best to explain what I know

The reality is that there are nearly an infinite possible combinations of tuning changes that can be made beyond camber... I would simply go with a pro setup that matches your track conditions... even better if you can find a local pro who's already tuned for your track!

I'm just an average joe and won't begin to claim that I know everything about each option, that's why I reference the manuals

a1

iTrader: (9)

bubbaslash

iTrader: (1)

Pushing...lower front roll center.
Loose...lower rear roll center
Traction rolling...raise roll center. Have someone "spot" the truck to see which end seems to be initiating the roll
Lowering roll center equates to raising the camber links on the tower side or lowering the camber links on the hub side.
Raising roll center equates to lowering the camber links on the tower side or raising the camber links on the hub side.
Lowering the inner hinge pin height also lowers the roll center, and raising the inner hinge pin height raises it.

30Tooth

iTrader: (1)

Tuning guides are amazing at contradicting themselves, that's the thing they are good at. They are only to be used for the starting setup, any change to that setup means the guide is compromised as a change that potentially has repercussions has been made.

Pretend that second paragraph about caster doesn't exist.

Camber depends of corner speed, more corner speed the car will need more camber for the roll generated and vice versa. As most of here said, 1 or 2 degrees of negative camber is the norm, if the car needs more than that then time to play with upper link length. And that's why the paragraph addressing rear camber is a slight mess, if the car doesn't have camber gain during roll (dynamic camber) )then you are going to increase negative camber (static camber) until the camber (actual camber) matches the amount needed at that corner(s), effectively compromising camber everywhere else.

bubbaslash

iTrader: (1)

fredygump

iTrader: (1)

I would probably focus more on roll center and ride height. Camber at -1 is probably ideal.

The theory on why camber improves grip for cornering is that as weight is transferred to the outside tires, the tire contact patch gets bigger. That's what happens on radial tires, atleast.

There is camber, and then there is "camber gain". Camber gain is when the camber angle increases as weight is transferred. A shorter camber link increases camber gain; a long camber link has less camber gain or no camber gain, depending on the model's geometry.

Roll center is about how much the vehicle rolls when turning. With a high roll center (high inside mount, low outside), the car does not roll and the suspension does not compress when weight is transferred to the outside wheels. With low roll center, the car rolls, because the suspension compresses when weight is transferred to the outside wheels.

Ride height and suspension geometry work together for this roll center thing. Changing ride height will have a greater affect on roll center than the camber link.



I run on dirt (low grip), and for that I prefer high roll center and long camber links in the rear. What this does is it makes the rear a little bit loose, looser than the front, so I can get good rotation. But the longer camber links (no camber gain) means that rear grip is consistent. The rear breaks away relatively slowly, giving me a chance to counter steer to catch it.

Short camber links would give a bit more traction, but at the risk of suddenly spinning and not being able to correct it in time.


The surface you run on makes a big difference on your setup. My understanding is that a clay setup will be the exact opposite of what I typically run. Why? More grip. High roll center will lead to traction rolling on clay, but this isn't a problem on dirt when there isn't as much traction.

urnotevenwrong

You've got a few things wrong there.

tsair

iTrader: (3)

Sounds like you need to change your username.

flagger

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