Under braking my car will have big lumps in its braking power (meaning it is not even and will slow down slowly then all the sudden quickly and back to slow again) and the car shimmies from 75-105mph. It'll still go in a straight line, though.
Is this an issue with my alignment, my rims being out of round or unbalanced, or my brakes? How do I fix it?? I got an alignment a few months ago, they said it was within spec, but they never told me what spec was or showed me my sheet.

Change out your warped rotors.

______________________________________________________________________________
Proud owner of a new 2004 SRT-4 in Flame Red

Originally posted by Fast420A
Change out your warped rotors. ______________________________________________________________________________ Proud owner of a new 2004 SRT-4 in Flame Red

yep, he hit the nail on the head. if your car shakes when braking then it is usually your rotors. mine do it around 60-40 so i am changing them out soon.

mine shakes too at speed and shakes sometimes VIOLENTLY when braking.
I've had all my rotors turned and it never fixed it. I did however notice that when turning the rotor, the brakes will rub in spots like the rotors warped but it's not. I think it's the hub but not sure. I plan on just swapping out that whole corner when I get some money. It's just the rear passenger side. I know the car was in an accident before I bought but but never knew how bad it was. :shrug

yep could be warped rotors could just be air in the lines.

it's not shaking under braking. The car shimmies/shakes when accelerating or coasting at any speed between 65 and 100 and the brakes don't shake, they just ... jump?

Hows your idle??
Sometimes my car surges when braking from the idle being a little funky and my rpms will increase a little causing a "jump" ing kind of feeling I guess.

But vibration when driving is caused by alignment/wheel balance, bent suspension pcs or lumpy tires.
and its probably really warped rotors.
get it all checked out I guess..

The reason your brake rate isn't constant could be from either your caliper sliding pins (bolts) arn't lubed good, air in your lines, or your master cylinder could be taking a shit.