i want to know all that you need to lower a m3 hatchback parts wise and i will probally have somebody do the install for me

 

A mild drop all you need are the springs, you will end up with rear camber right on the edge of in specification. You can correct this camber with camber correction links. I highly recommend keeping the camber at nominal to avoid excessive tire wear.

It's a fairly straightforward install if you just put in the springs, if you want the camber links installed, you have to drop the rear suspension carrier ~1-1.5" to get clearance for one of the camber link bolts to come out (it's the top most suspension link in the rear suspension.)

 

so camber links are another way to drop the car

 

No...springs drop the car, but when you lower it, the tires will tip inward at the top (causing excessive wear on the inside edge of both rear tires.) The camber links are a little longer than stock and will correct the camber back to within stock specifications.

There are 3 different things to keep in mind with tire position: Camber, caster and toe

here's the easiest way to explain it:

Toe
Stand with your feet parallel, (imagine they are your tires on either the front/rear suspension)
now point your toes inward toward each other, this is "toe-in" the opposite is "toe-out" Toe helps with the self-centering characteristics of the car, but excessive toein/out can wreak havoc with your suspension/tires

camber
Now with your feet parallel, make your legs go bowlegged (knees spread farther apart than your feet), your legs represent positive Camber (top of the tires tipping outward), positive camber is bad. Now tip your knees in, that is negative camber, negative camber helps with the handling of the car, but excessive camber can wear your tires on the inside edge real fast.

Caster
This is really a front suspension characteristic. Imagine a centerline drawn from top to bottom down the side of your tire (through the hub), now rotate this line clockwise a little. The angle from vertical to the line is the caster angle, the amount of caster affects the steering characteristics of the vehicle.

On the rear suspension of the Mazda3, there are adjustments available for everything except camber, so by replacing those links with longer ones, you can get your tires back to a slight negative camber position (about -0.2 degrees, without the links I was at -2.1 degrees)

FYI....The springs always set the ride height of the car. (whether they are air springs, coil springs, torsion springs, whatever.)

 

ok thanks i kind of understand it so how much would the whole set up cost with out the install

 

so lowering is diffrent then dropping?

 

lowering/dropping are the same thing.

Springs are around $200, camber links are about the same....I did all of the installation myself.

Eiback springs (Pro-kit) & Mazdaspeed Camber Links are what I used....I've had VERY good experiences with Eibach springs.

 

ok let me get this straight the springs lower the car and the camber links balance the car so their is not as much wear on the inside of the tires and if i want everything it would be about 400 dollars

 

exactly...

the camber links are optional...it actually handles better without the camber links, but I put so much mileage on my car that I couldn't live with the reduced tire life (~25-30K/year)

 

is that with all season tires and how much diffrence does it make having the camber links