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Camber and toe on Circle track front wheel drive

Practical Corner Weighting

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On a cement circle track front wheel drive car and this is for both Camber and toe, do i apply camber and toe to all tires evenly? Or does maybe the inside wheels get more camber then out side? for the Toe do i just add toe in or out to the front left tire? do i add or take out toe? or to the outside wheel? Do i have toe out on the rear wheels as far as they will go, i mean the inside wheel has toe in as far as possible and the outside right rear has toe out? so when going around the track the rear wheel track in a circle instead of straight?

Hi Nathan,

Are you talking about a car that is (usually) only turning in one direction?

If this is the case, then usually the alignments are asymmetrical, to the point that the inside wheels will run positive camber angles, and the outside wheels have negative camber. This will also apply to the toe angles, with some toe in on the inside rear wheel and toe out on the outside, this will have the car "crabbing" in a straight line, but assist in the turn as the rear wheels are already cornering.

On the front, the toe angles will be more similar, but the ackerman angles and steering setup may be biased so that the inside wheel has a greater angle gain to the outside wheel to try and generate more tyre drag in the inside wheel to get the car to pivot around this point.

As Steven said, it's common to have asymetrical settings for a circle track because the vehicle is only loaded in one direction and so compromises aren't required for both.

Some suggestions, which may give you some ideas for investigation.

Positive inside camber will help even out the tyre loading across the inside tread, in the same way as negative does the outside, how much will be down to experimentation. There are a few ways of doing this, one is the static settings with a 'flat' car (the static ride height is the same on left and right), and the other is with a 'canted' car where the car is set with a higher ride height to the outside with the intent that when laterally loaded in the corner the car is 'flat' - this can make a big difference if aero' aids are allowed as the front splitter/dam can be run very close to the track surface for best affect.

It is also common to use different caster settings to the left and right, there are two main reasons for this, with the first being it's affect on camber in (especially) tight turns, and the second because it can be used to reduce the steering load in turns.

As Steven said, in some instances it can be useful to use net rear toe offset to have the vehicle 'crab' as there will be a little more 'side-force' from the wind presure on the side of the body, but this will also depend on whether you have an understeering, or oversteering car - with understeering it may be better to run it 'straight' to reduce drag slightly and better use any aero'.

There are two schools of thought on whether to run a 'toe-out' or 'toe-in' setup. Steven subscribes to the 'drag' theory, which I expect 'might' work on rear drive and/or dirt? For your application I'd go with neutral, or maybe slight toe in, and my reasoning is - you are probably running a relatively low power vehicle so drag will slow it down, and a tyre's slip angle depends on the loading - the higher the load the greater the angle - and so the outer will be expected to have more slip (difference between the wheel and direction and actual direction of travel under load from tread and carcass distortion) than the inner. This will, of course, depend on any suspension/bushing flexing and tyre pressures, so will come down to testing.

As I expect you to have gutted the car, you're going to have to give some thought to the rear stiffness in roll. In theory, you will probably want to run it with the inner rear around the point of lifting from the track, this is to maximise the load to the outer rear to promote slip/oversteer/reduce understeer and more evenly load the front tyres. This is dome with spring rates and anti-roll bars and, again, there are two trains of thought - run stiffer springs/soft ARB or run stiffer ARB and softer springs for most affect. With a smooth track, springs may be better, but with a bumpy track that can be rather twitchy as the rear may skip. Depending on your options, you can also play with damper settings, stiffer rebound will usually promote turn-in oversteer, stiffer compression will tend to promote exit oversteer, and vice versa.

Back to the front, as this is doing 3 things - steering, applying power, and braking - it's going to have a big affect on overall performance and tyre use. You will probably be looking to run it on the softer side. If you're running a spool/welded diff (if legal), you may wish to consider running a larger diameter outer tyre, and this will have three main affects - it will naturally turn the vehicle, it will add inner positive and outer negative camber, and it will affect 'wedge'. Something else is the wheel offsets as this will affect the scrub radius and the greater it is the more it will 'steer' the car under power/braking against the steering input - basically it will affect the steering loads for the driver.

That should be some food for thought.

Thank you for all the input. the car has been built and yes the rear left wheel does lift in corners. My question is of the front toe do i only adjust the right front tire with in or out toe? or do i adjust both front tires with toe in or out? Not sure, i am guessing that with the steering set straight that i would adjust toe out on the front right tire so when i am in a corner the front left is tracking the inside turn and with a little toe out the outside tire that is tracking a little larger turn radius maybe? and with camber since the right side of the car has more down force then maybe have more camber on it then the inside tire to allow for even contact patch in corners? The car has plenty of power so drag on the straights is ok i just need to corner better. It is not loose in the corners but i do get some scrub when i am applying power exiting the corner. would liek to figure out how to get more contact in the front so not to lose the power scrubbing

Hi Nathan,

For adjusting the front toe, it doesn't matter whether you adjust inside, the outside, or both - it all has the same effect. I'll give you 3 different examples of static toe settings below:

1. FL = -2mm , FR = 0mm

2. FL = 0mm , FR = -2mm

3. FL = -1mm, FR = -1mm

All three of these settings have the same end effect on the way the car will behave. The only difference will be the angle of the steering wheel that the driver sees. For the front axle, it's only the total toe that matters. The driver will find a natural equilibrium point with the steering wheel regardless. Hope that helps!

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