Setting Toe-in/out at home

[Talasas]

I solve a lot of things in my sleep and last night I had an idea how to set the toe in/out at home on my AE93 SX.

Now I have dug up some specs as to what it should be when wheel alignment is serviced which is all well and good. But my question is has anyone ever set their own toe without the need for a wheel alignment 'machine' ? My method is pretty simple it DOES work.

Anyway, basically my front and rear toe are out as there was a bent control arm on the rear and the front was dinged so the steering tie rods are out.

Also, would anyone have a reason for me setting the rear toe to zero? I've been told by some reliable sources that having zero toe on the rear should reduce understeer by increasing the tendency to oversteer. From what I've seen this can't be too bad overall, unless of course it causes too much wander, in which case would toe out be a good idea?

[Bahnugget]

ooh, im keep to know if eliminating rear tow creates oversteer, thats always fun!

[Ben Wilson]

I did my daily about a year ago and the tyres seem to be wearing evenly.

I just used jack stands, string and a ruler.

[e30-323ti]

Easily done with brooms & string.
A bit time consuming and not quite as user friendly as the electronic types.

http://www.racerpartswholesale.com/smart1.htm they charge you $380US for some fancy broom handles.

[The Last Streetfighter]

My brother and I "eyeballed" my front alignment and toe with a tape measure when I got my car back on the road after the new engine install. But only long enough to get to a shop and have it done properly.

[myne]

I have 1mm toe out on all 4 wheels.

I can go up to any corner too fast, understeer mildly, back off, and then neutrally oversteer.
Tis good

[Talasas]

Okay well I've had a crack at this. I used string to measure the inner rim distance to the outer retaining bolt on the rear control arm. They were different so I set them the same and adjusted both sides so I have 2mm toe in.

Now the problem it it feels like it's steering the car now (in that both wheels are parallel but may not be in the same plane as the car) which complicates matters. This is because of a combination of the once bent control arm clonking about (I have no idea why, it is straightened) and me not being sure if my reference point are valid.

I'll look into this some more tomorrow.

[Ta22boy]

Hey,
I used to be a wheel aligner for a couple of years, and when setting up a front wheel drive car, you really just want to set the front and rears to zero toe or slightly toeing it out (1-2mm), mainly to keep the tyres wearing well. Too much toe in will make it really jumpy and resposive in the steering and oversteer, and too much toe out will cause it to understeer, and wear out the insides of the tyres. If your car is wandering a bit, get a aligner to play around with your casters (if adjustable) because just say the are both set at 20 minutes (60 minutes in a degree) then it really should wander to the left because of the natural slope of all roads, and get the left hand front pushed slighty in front of the right (caster only applies to the front). Camber will also play a big part in how oversteer/understeer and if possible get them put out to around half a degree negative and then it should handle like a beast. Also it would be a good idea to just get the steering arm fixed, as it will wear out that tyre, no matter what you set the toe too (guessing it would have messed up camber from dealing with this problem before) Anyways hope i have helped a bit...

Scott

[Ta22boy]

just on that last message, Measure it from the front of the rear tyres, tyre to tyre, and then do the same at the rear of the tyres, then work out the difference in length and just say its 1235mm at the front and 1233mm at the rear, then its toeing out 1mm a side. which is not bad at all....

Scott

[RWDboy]

This is a very very over-simplified generalisation, toe-out makes things more stable in a 'lateral' sense. At higher speed the tyre's footprint will naturally 'toe-out' a bit, making it difficult to change direction. So for most road cars a bit of mild toe out is a good starting point because they don't go fast enough to really need crazy toe-in.

Negative camber for the sake of negative camber can be a bit frustrating. Usually camber is used to fine tune the wear and contact patch on the road, and it depends what kind of driving you like to do. If you are doing alot of track days, then negative camber will be quite useful (particularly on the front) because the car will roll a fraction and also at higher steering angles you get more and more positive camber being generated due to caster (partly countered by the compression of the suspension usually)

But for road use - i doubt you should be pulling that much lateral force around a corner to require that kind of set-up on the front end

Pretty much i suggest using a small amount of toe-out (1-2mm) on the front, with anywhere between 1/4 -ve camber to 1/4 positive camber as a start and then monitor your tyre wear. Also as far as setting-up caster angles, usually manufacturer settings are ideal (and often aren't very adjustable anyway).

And definitely get the tie-rod/steering arm fixed! That will play all sorts of havoc with the geometry of the steering throughout the range of movement - so fix it straight away!

Also - in regards to you setting the toe with the control arm bolt as a reference - that may work, but you should also check other points too - and be as accurate as possible, try to write down the possible errors in your measurement and get them set as accurately as possible! You could even try and measure out a mid point between the control arms and use that as a reference point, just be sure to keep track of all the possible errors in your measurement.

Lastly - 2mm toe-in on the rear will be nervous at lower speeds. So it may very well feel like the rear of the car is a bit twitchy!

[RWDboy]

Oh i forgot to mention about rear-end set-up stuff. Usually the rear end doesn't require that much negative camber because it doesn't have the same problem with steering angle that the front end does. Also, like the front end, the camber will change as the strut compresses - and obviously the strut will compress when either accelerating hard, or cornering hard (and leaning on the tyre due to body roll). As such it'll only need a small amount of negative camber, probably 1/2 a degree at most, and as i said above, toe in should be fairly conservative too as it may make the car nervous. If you plan on cornering at higher speed, then yeah you'll need more toe-in as otherwise the rear will tend to steer outwards (leaning on the outside tyre with too much toe-out == oversteer).

Anyway just play around, go to a track day and push the car hard and see what works for you and what doesn't. You probably won't want to bother with a scientific/engineering approach as you aren't trying to optimise lap times, but you might be able to make the car handle more to your liking.

[Talasas]

Hmm, that does give me a lot to think about.

Basically what I did was measure the distance between the front of the rear rims and the back (as you've said). I then measured the inner rim distance to the control arm bolt. This is what I got (from memory):

rim fore span: 1492 mm
rim aft span: 1504 mm
left rim-to-bolt: 528 mm
right rim-to-bolt: 520 mm

So what I did was set the left side to 518 mm (taking into account I meansured from the aft of the rim, which I think may be a problem come to think of it). I then set the right side to 518 mm. Checked the toe again and got within 2 mm. Errors are taken as +/- 0.5 mm.

So now I feel I'm way in over my head. Since I measured from BEHIND the rim, could that be bad? I'm actually thinking setting it to 518 mm I've gone backwards.......No....that's right, if I set the toe angle FURTHER OUT then it should reduce the distance from tthe BACK of the rim to the control arm bolt right?

[Talasas]

Oh and one big question, can I do this wih the car on jack stands? I've been doing it with it on the ground as the manual said...

[Jonny Rochester]

The guy has a AE92. There is no caster or camber adjustment. You can only adjust the camber a bit by loosening the bolts, tilting the wheel, and doing them up again. Or getting the Whiteline Magic camber bolt kit. Normaly you can only adjust front and rear toe. I do about 1 wheel alignment each day.

I set front toe to zero, or very slight toe-out if the outside edge is wearing. Maybe 1mm toe-out each side, no more.
I set rear toe to 3-4mm toe-in total, or 1.5-2mm toe-in either side as the specs say.

The rear toe-in is to keep the car stable and not prone to oversteer. So yes, this is something you can play with if you want. But zero toe is not going to make it dangerous. Think of the KE30, KE70 corollas, HiLux etc, they all have zero rear tow. (Fixed axle, although often welded crooked).

[Ta22boy]

nah make sure you do it on the ground, as when you have it in the air, all the suspension is dropped down and not properly in place, like it is on the road. Also i wouldnt worry about measuring it from the tyre to the bolt, just measure between the tyre, at the front and rear and that will give you your difference. and if you have toed it out more, then it will be coming closer to the rear bolt....