Who is right, my lecturer vs car bibles

[h00t_h00t]

I'm at college studying to become a car mechanic, one of my lecturers said that if you lower a car by 60mm as one of the oher students has, it will mean you have to reset the castor and camber and some other suff.

Earlier I was reading www.Carbibles.com and came across this

What if I get shorter springs to lower the car? Will I need to adjust my caster and camber angles?
Generally the answer would be no. Most cars have a good 10-13cm (4-5 inches) movement in their suspension from the factory. As most of the lowering springs you can buy only lower by 2-7cm (1-3 inches), your suspension should still be well within it's designed operating limits. Therefore, caster and camber angles shouldn't need looking at.

Who is right?

[magracer]

I say you will have to perform a full alignment due to change of all the geometry in the suspensión. But, why wouldn't you? You are seeking to extract more performance, and for that you would try to set the perfect alignment with your new settings.

The exception to this rule are cars with rear suspensión like my Saxo: they have a torsion bar at the rear. Then "you set and forget". Still, you would have to realign the front suspension.

[deffenbaugh03]

Well if you want the castor and camber to be exactly the same as before you lowered the car then yes, you will have to change it. Lowering your car changes the suspension geometry, wether or not its still within designed operating limits is the thing thing i'm not sure about.

EDIT: yea what he said ^

[PerfAdv]

If you lowered 60mm (or ~2.5 inches) and didn't adjust alignment you'd end up with lots of negative camber. Some negative camber is good for cornering but you don't want that much, since you'll never () corner that hard on the street and it'll just end up balding the tires on the inside edge.

A lot of slammed Civics out there suffer from this affliction; front: //+ +\\ and back: //= =\\

EDIT: and like said it applies only to independant suspensions. Since rigid axles and torsion beams don't change camber during compression.

[Matra et Alpine]

Some independants don't either.

It's to do with geometry and the designers goals in the chassis and suspension compliance.

[h00t_h00t]

I would have thought that there was some movement in the suspension to make up for when it is loaded up to its maximum allowance, the car that has been lowered 60mm (Vauxhall Corsa) doesn't have noticable camber on any of the wheels and the whole job was done cheaply...

[hightower99]

droping a corsa 60mm will give the front wheels more camber but you might not be able to see it when the car is standing still.

I suggest measureing the camber just for laughs and seeing how much it changed if it changed more than 2 degrees than I would suggest you change it.

[h00t_h00t]

I'd rather watch him wear out his expensive low-profile tyres ¬_¬

[MrKipling]

Aside from anything else, lowering a car by that much would do a lot to the dynamics, so you'd want to look at the settings regardless of whether the change of ride height had an actual effect on the camber.