sticky cha cha cha!
^ Yeah, well the effect on camber curves is the big concern. Macpherson strut designs like we have are not so good when it comes to camber curves. If you lower the car past a certain point, then the remainder of bump travel will cause positive camber gain. And ideally you should have negative camber gain under bump travel to counteract the off-camber effect of bodyroll.only1db said:what we really need to find is our roll center...because going to low can actually hurt the performance.
It varies depending on the car. Something like 1/16" total toe out would be fairly reasonable to use and you'd benefit from better turn-in and a better ability to power out of corners. It may be worth it to you to try that setting if you autocross or do track days often. I played with toe out a little on the Elantra and it certainly helps the car rotate.only1db said:agreed with the alingment...althought i heard from a mechanic around my way that used to tune...that you might actually want a little toe out...becuase on acceleration the car has a tendency to toe in...
It depends on the car. Adding positive caster certainly helps. It creates more camber change when you turn the wheel and creates a more on-center feel to the steering. The only problem with it is that the amount of camber change is determined by how much you turn the wheel. And that's not ideal because you can have the same amount of body roll around a tight 30 mph corner as a fast sweeping 70 mph corner.I have been discussing the chassis design with a few people at Art Morrison Enterprises. They don't recommend agressive camber settings, but suggest changing caster angles as a way to improve handling. Factory caster settings are around +2.6. Changing that to +3.2-3.5 will improve the drivability of the car especially in corners.
Nope, not too aggressive at all. Sounds good to me.Eventually I'm going to install new struts/springs/sway bar/front strut bar (eibach elantra springs + kyb GR2 tibby struts). I was going to have an alignment shop set the camber at -1.5 front and -1 rear (buying camber plates). Toe at 0, and caster what the drop gave me (probably Left Front: 2.6 Right Front: 2.7)
Do you think this is too aggressive? Some said it would be, and tires would wear too fast. I'm looking for a mix of daily driver and autocross car. Thanks.
It depends on the car. Adding positive caster certainly helps. It creates more camber change when you turn the wheel and creates a more on-center feel to the steering. The only problem with it is that the amount of camber change is determined by how much you turn the wheel. And that's not ideal because you can have the same amount of body roll around a tight 30 mph corner as a fast sweeping 70 mph corner.
Again, of course it's a compromise. If your car never sees the track then adding some positive caster and a more mild camber setting of -1.2 degrees may be more practical for you. But once you get into racing a car with a Macpherson strut setup and 3 degrees of body roll you'll see how you'll need more negative camber as well.
Unfortunately caster is not an adjustment you can make unless you have something like camber/caster plates.
Too much camber will wear the tires unevenly. My car has -2 degrees LR and -1.4 degrees RR. Most of the contact patch is on the inside of the tire and that can wear the inside faster. Most of my driving is DD.I just laugh on the inside whenever an alignment guy tells me that the camber I'm asking for will kill my tires. But I've been doing it for the past couple years (first with the Elantra, now with the STI) and I actually get more even tire wear this way with what I put my cars through. Toe is the tire killer, not camber.
I'm not saying they're wrong but they did design the car very conservatively when it comes to handling capabilities. Some BMW's will use as much as 8 degrees positive caster AND more negative camber as well.For daily spirited driving and salom and skidpad testing, AME engineers designed the IFS and IRS systems that have more positive front caster and less negative front camber than the rear camber setting.
Macpherson strut suspensions are very different from double wishbone setups. With a double wishbone setup the suspension will gain negative camber as the suspension compresses, counteracting some of the off-camber effects of bodyroll and helping to keep the tires oriented properly even in corners. This is why F1 cars use double wishbone setups and why it's so desirable for any race car that has to go around corners.On my car, I have an independent rear suspension with unequal length control arms. On such systems camber remains constant within a certain range of suspension travel. However, on my car, and those like it, if you lower the car my 1/2 inch, either by putting stuff in the trunk or rear seat ort by hard cornering, camber radically changes due to the lowering of the car to that level.
The inside tire wear due to the -2 degrees camber would be very slow by comparison to a misalignment in toe. I've seen plenty of people complain that camber caused their premature tire wear but neglected to address the fact that the toe wasn't right either.Too much camber will wear the tires unevenly. My car has -2 degrees LR and -1.4 degrees RR. Most of the contact patch is on the inside of the tire and that can wear the inside faster. Most of my driving is DD.
On my car, under high speed driving, I get a lot of squirliness in the back end with the uneven camber. Camber is supposed to be even, but it is between .6-.9 degree difference between right and left due to the left upper control arm being 1.2 inches shorter than the right upper control arm. As the car drops in height due to a load, you see the camber increasing negatively that is uneven. This uneven camber creates a pull condition that causes the rear end to react differently than you want. Without a load, camber on both sides is fairly equal, but 1/2 inch of lowerng the car causes the camber to become uneven. Due to the pull my rear toe is set at 3/16 in just to keep it fairly stable and track right (due to the excess camber on 1 side). If camber was -2 degrees on both sides, I would not have a squirly problem, but camber on my car is not even on both sides like it should be. The toe setting I have counteracts the camber pull that is present in my car.But of course even if the toe is aligned perfectly you will see some wear due to aggressive camber settings. It's pretty minor though and even -2 degrees will work for a blend of daily driving and autocrossing. I wrote all of this for people who like to go around corners of course. And I suggested a range between -1.2 and -2 degrees front camber depending on how much of that you put your car through. Autocrossing is the extreme and a completely stock Elantra would probably see in excess of 4 degrees of body roll when pushed to its limits.
I am wondering the same thing and I have 5 of my techs plus an engineer at Art Morrison Enterprises trying to figure out a solution. If it would be possible, I would try to get both upper control the same length, but that is not possible because there is not enough space to get the left rear upper control arm in the same geometric angle as the right side.^ That's really odd that the upper control arm on the left rear is different than the right rear. That would create all sorts of problems with the geometry. Why in the world would Hyundai do that I wonder.
Yeah, what I meant by "at rest" was the natural position of the suspension when the car is sitting still with the driver inside. And static would be the same thing.Basically, by setting the car to negative camber (static: means at rest right?),
I think you've got it.when turning one way or the other, the suspension compresses, on one side of the car or the other. In this instance, the lowering effect of the compression pushes out that wheel(s), which induces positive camber. By setting the car to negative camber initially, when making that turn or curve, and positive camber is induced, in essence, the wheel flattens out, without actually passing the center point of the wheel (towards positive camber).