I have just had my WRX steering geometry checked after 24k miles. The FAQ on SIDC suggests 1mm front toe-in (Prodrive recommendation) or 0 +/- 3mm (Subaru specification). Perry's of Aylesbury who have a brand new computerised test rig say they only measure in degrees not millemetres.

I settled for 0 degrees 5 minutes toe-in front and rear and 0 degrees 50 minutes negative camber (Prodrive recommendation).

So, is 1mm toe-in equivalent to 0 degrees 5 minutes? Or have I got the wrong end of the stick!

Kim Martin

PS I can recommend their engineer Dean Westbury he did a great job and the steering feels much better even at slow speeds.

 

Kim Martin.. First the raeson for using degrees vs mm .. when using mm for measuring toe you get inconsistent results because of tire diameter. Thus 1mm of toe on a 15 inch tire is more "total toe" than 1mm on a 18 inch tire. Toe being measured at the tread.
One degree toe is one degree toe on any size wheel..

I measured my 205-55-16 stock wheels and they are 24 3/4inches in diameter(628.65mm). So with that measurement and 1 degree of toe it would equal 0degrees-5miniutes-28.1006seconds

Toein in general makes the car stable but pushes

Toeout in general makes the car react quickly and not push-thus gives you more steering with the loss of stability, especially over ruts the car will wander more

Hope this helps Andy

 

Andy,

Thanks, definitely more logical to use degrees - makes you wonder why the specification uses millemetres..........

Kim Martin