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wandering steering
IDONTBELEIVEIT - 15/3/09 at 04:13 PM

done about 300 miles now,been blatting around country roads,today and seems to wander all over the shop,constantly fighting steering wheel,
running 4mm toe out on the front
2mm toe in on the rear
over the height of the wheel from bottom of rim to top of rim 2mm neg camber front
and rear about 1mm neg camber
any thoughts
wayno


whitestu - 15/3/09 at 04:22 PM

You need to be running parallel or toe in at the front.

Stu


David Jenkins - 15/3/09 at 04:38 PM

What he said...

Toe-out can be scary!


britishtrident - 15/3/09 at 04:41 PM

Toe-out on a rwd car kills people

You need toe in set to parallel to 1/16" toe-in on the front.

Rear toe-in shoul be about 1/8" to 3/16"

In case of any doubt on accuracy of measurement err on the more toe-in side of the error band.

[Edited on 15/3/09 by britishtrident]


IDONTBELEIVEIT - 15/3/09 at 05:01 PM

scary ain't the word


Phil.J - 15/3/09 at 05:54 PM

If you have any compliance in the suspension (Rubber bushes etc) then run about 3mm toe in. If you have no compliance ( spherical bearings/rod ends etc) then up to 1/16th toe out can increase the initial turn in in corners without affecting the straight line stability.
If it's as bad as you describe then I would be more suspicious of front or rear bumpsteer. You did check the bumpsteer at the construction stage didn't you?


BenB - 15/3/09 at 06:18 PM

Toe-out is bad. Go for a bit of toe-in, then under power the wheels will get "pulled" into a neutral stance. I had loads of toe-out for SVA and it felt blooming 'orrible...

The Me109 fighter plan had some quite scary toe-out and this caused quite a few crashes on landing....


nitram38 - 15/3/09 at 07:26 PM

Did you do the toe out because of centering?
If so do a search on sorting that, because when you remove the toe, you will have another problem........................


Ninehigh - 15/3/09 at 09:45 PM

Why's toe out so bad?


David Jenkins - 15/3/09 at 09:51 PM

Toe out makes the steering twitchy and unpredictable on a RWD car - you're always chasing the steering to keep the car going straight.

Imagine the chassis of the car pushing forward - the wheels & tyres resist this and, if you've got softish bushes then you'll end up with extra toe-out! Even more fun...

Toe-out is for FWD cars, toe-in is for RWD cars.


NS Dev - 16/3/09 at 01:18 PM

just to muddle (no, don't do it on a road car!! )

toe out can be used on the front of a rwd car that doesn't like to turn in, helps "de-stabilise" the front and and help turn-in.

twitchy though.

We use it on the caterham superlight racer, never used to with k series vhpd engine but need it with heavier duratec.


IDONTBELEIVEIT - 16/3/09 at 07:03 PM

the problem came from me assuming the rear wheelbase was the same as the front and pulled a straight line from rear to front and set up so infact i had about 12mm inclusive toe in,reduced it now to 1.5mm inclusive,what a difference,now just got to set up the rear,i'm gonna make up a proper jig tommorow,what are you guys running toe and camber wise
cheers wayno!!