Rear Toe

[Freebaggin]

Could someone confirm the effects of rear toe either, toe in, 0 or toe out, especially for R33 Skyline GTS-Ts.

Pretty sure I understand front toe effects but still not 100% sure what happens with the rear. Is it simply the reverse of the front, ie. front toe in induces understeer due to less overall grip, so rear toe in induces oversteer becuase of the same reasons?

SK has recommended 2mm toe in for the rear end of my car (as part of other recommendations) to help dial out rear oversteer which I'm still trying to get my head around.

Cheers!

Edited April 12, 2006 by Freebaggin

[Sydneykid]

Toe out can be referred to as an "ubstabilising" setting

Toe in is considered a "stabilising" setting

So if you want more response, go for toe out

If, on the othe hand, you want more stability, go for toe in

Hence toe out on the front makes that end of the car more lively, reponsive to inputs such as steering. Toe out is on the front is good for improving the initial turn in to a corner for example.

Conversely toe in on the rear makes that end of the car more stable, less reponsive to inputs such as power application. Toe in is good for decreasing the power oversteer on corner exit for example.

As always you get nothing for nothing.

If you run toe in on the rear to help decrease the power oversteer the side effect is more reluctance to run into the corner. The rear end remains stable rather than move out to assist the turn.

So the common RWD Skyline setting is toe in on the rear and toe out on the front.

That should be enough to get you thinking

cheers

Edited April 12, 2006 by Sydneykid

[djr81]

Could someone confirm the effects of rear toe either, toe in, 0 or toe out, especially for R33 Skyline GTS-Ts.

Pretty sure I understand front toe effects but still not 100% sure what happens with the rear. Is it simply the reverse of the front, ie. front toe in induces understeer due to less overall grip, so rear toe in induces oversteer becuase of the same reasons?

SK has recommended 2mm toe in for the rear end of my car (as part of other recommendations) to help dial out rear oversteer which I'm still trying to get my head around.

Cheers!

The key to understaning rear toe effects is to understand how a tyre generate cornering grip. Put simply, when turning a corner there will always be a difference between the direction the tyre is pointing and the direction in which it is headed. This is known as the slip angle. Up to the grip limit of the tyre the higher the slip angle the higher the cornering grip. The amount of grip the tyre generates is also proportional to the load on the tyre, ie vertical force acting on it. The more downforce on the tyre the more grip it can generate.

If you think about the rear suspension, when travelling in a straight line the two rear tyres, by courtesy of the toe in, are both generating a cornering force - but they are cancelling each other out. When one rear tyre is loaded more than the other (ie the outside wheel when cornering) the toe in/out on this wheel becomes the point of interest and the inside wheel can largely be ignored.

If you put toe in on the rear suspension (ie front of the wheel pointing in)you are, when cornering, essentially doing the same thing to the rear of the car as turning the steering wheel does to the front. This makes the car, in a relative sense, understeer a little more than it might otherwise.

If you put toe out (ie front of the wheel pointing out) you will have the effect of adding a little more oversteer to the car when cornering.

The point to be a little careful of is that when you go over a bump in the road and this only hits one wheel - too much toe in will make the car steer from the rear. Not much fun.

[Freebaggin]

So that's 2mm TOTAL toe in on the rear or 2mm each for a total of 4mm?

[Sydneykid]

So that's 2mm TOTAL toe in on the rear or 2mm each for a total of 4mm?

That’s 2 mm each side, be specific with the aligner. Some of the dumber ones think the rear is the same as the front and they can set it at 4 mm total toe in.

cheers

[dangerous_daveo]

Now the next question... The effect on tyre wear?

[Sydneykid]

Now the next question... The effect on tyre wear?

Not enough to notice

cheers

[mad082]

the amount of wear would come down to how much camber vs toe. my skyline has been lowered and i was told that instead of getting a camber kit, get the toe matched to the camber to make the tyres wear evenly.

the more toe in you have, the more outside wear you get and more toe out the more inside wear you get.

so if you have lots of camber and lots of toe out you would get extreme inside wear.