Gun Jam

humm that sucks...

It should still pull with disc brakes then (if it truly isnt brakes)

And a bent A arm should have shown up during the alignment (I would think)

I dont know a whole lot about alignment but it seems odd to me that you could mess with the alignment enough so the car tracked straight AND stopped straight... Seems to me that the car would pull right when driving and then track straight under braking.

Did they explain how it could track straight and stop straight with your (way messed up) numbers yet not stop straight but still track straight using Daze's numbers?...I bet not.

-Gun

JDraper

Hmmm...could it be that there is some hidden damage in the front of the car that is allowing the control arm to move under braking? A weakened frame member or shock tower issue? I'm wondering if when you hit the brakes, part of the suspension on the left side moves backwards and twists a little, throwing the car out of alignment and causing the pull.

Dtimekw

Agreed. I asked the same thing. The only answer I got was "I set it where the computer tells me". After the new install, I will go somewhere else for the alignment. I don't think the brake upgrade will fix it but at least I'll be able to rule it out and have disc instead of drum

Dtimekw

Yeah, I am thinking the same thing at this point. I don't see any ripple in the frame rails but that's not to say there isn't any damage. I've replaced everything but the UCA/LCAs and bushings. I also upgraded everything to poly bushings to stiffen the front end (except the strut bushings - midolene).

The only evidence I have is the driver's shock wants to sit far back in the tower. To get the pull out, I'd have to force it further back (pos caster). That's what makes me wonder

Gun Jam

during braking weight is transferred to the front of the car and physically exerts more load on the front suspension.

Im not suggesting you do this...well not exactly as described its just one more thing to mull over:

What if you put 300 pounds of sand bags on the front of the car to simulate a loaded front suspension. I wonder if it would now pull left just like it does when you hit the brakes.

This would be awesome test if you could come up with a realistic way of adding a decent amount of weight over the front a-arms. IF something is shifting when loaded it should show up.

-Gun

Dtimekw

Hmm. Interesting idea. This should check if bumpsteer is the issue but since the force of the weight would be straight down (bumpsteer) I am not sure if it would contribute to <something> moving backwards to cause a negative caster on the driver's side (if negative caster on the drivers side is the problem). I do think you are on to something though. Since bumpsteer is caused by the "nosedive" effect and changing toe, it could be that a I have a problem with the driver's side steering which is sitting on the edge of too much toe out and when bumpsteer is thrown in there, it would cause the driver's side pull during braking.

With that said, while the car was hooked up on the alignment rack. I pulled down and pushed up on the front end. I notice a change in toe and camber but not caster. So, your idea of adding weight does seem to have some validity. I just don't know where to find 300# of dead weight that I could cram in the front end. I was thinking along the same lines as you Gun by compressing the front springs to force bumpter but could not figure out a safe way; that's why I am going with stiffer 1" lower springs.

I also found that once the alignment was set, it changed after a test drive. So much so that it had to go back on the rack. It seems the suspension could be loaded and unloaded but did not return to the same position (up and down); another reason the change the UCA/LCAs and stiffer springs.

I am going to play with this a little more, perhaps find a way to load the front end down and see if it takes the same amount of brake pressure to get it to pull left or less (which would indicate bumpsteer being the issue).

Gun - I like the way you think. Old school all the way!!!

**EDIT** - As I ponder the bumpsteer some more, I realized that since the steering in behind the spindles, during a hard braking, the susupension would compress and cause toe in, not toe out. So I think I am back to something moving backward during hard braking.

Please keep the ideas coming!

JDraper

Have two people watch your car when braking, one on the left and one on the right and have them look for the wheel deflecting towards the rear when braking to see if the suspension is moving around under braking.