For those who want to be truly **** about your alignment, get it done while you are sitting in the car.

The tech was telling me a story about how he had to align this lady's car with her in it because she weighed 400 lbs and she was always bringing the car back in due to it pulling to one side. That gave me an idea. I weigh 240 and I wonder what that does to my camber and toe as opposed to a static alignment. I got in the car while it was on the rack and I threw off the alignment by a couple points on the left side, front and rear. The tech had no problem setting it into spec with me in it. I most often drive alone anyway so this works out well. Even without me, it's in spec. But when I get in it, it's now precisely in spec.

Maybe it's only psychological but driving to work this morning on a pretty empty toll road (translate into FAST), the car felt incredibly neutral.

 

by a couple points do you mean it was -1.0 without you in the car and -2.0 with? or do you mean it was -1.0 and -1.1?

specifically. how much did it change with you in the car?

 

The front went from a static -.8 (this is where I want it) to -1.1 on the left side when I got in. The toe also changed slightly. This is on Tein 350Z S-techs, which are pretty stiff but still progressive. The rear changed by .2. and toe shifted as well.
Now the car is statically at -.5(L) and -.8(R) and with me in it it's -.8 for both. The rear is set up with a .2 spread. Toe is corrected accordingly.

 

most mechanics won't let you get in the car while they are doing the alignment.

but yes, this is a good idea for those who can do so.

 

thats how I had mine done. Go to alignment shops that specialize in race/track prepping cars and they'll usually let you sit in the car, or have a ballast to mimic your weight on that side of the car

 

i got in mine yesterday and i centered the wheel to my centering

 

most race cars are set up with the weight of the driver sitting in the driver seat...

so this guy knows what he is talking about...

Good for you...I only wished all techs were so observant.

 

Most good alignment shops around here will set the alignment off by a bit to compensate for about 150-200lbs on the driver's side. But of course nothing beats the driver sitting in the car.

 

That's how the local shops wanted to align my car. But given that my custom coilover setup is very stiff and I'm small guy (5'7, 150lbs) that didn't affect anything.

 

Easy to calculate the camber change by measuring the body [appropriate side near tire] to ground clearence with and without drivers weight.

Each inch changes camber ~~0.83 degrees [for a 26" tire diameter].

If the driver seat is at center of gravity fore/aft, then caculate vector of weight offset [L-R].............oem design assumes driver weighs 150 pounds.

 

If the driver sitting in the car matters, then I would think that the amount of gas in the gas tank would contribute to an inaccurate (or accurate, I guess depending on how you look at it) alignment. You could get it aligned while sitting in it with a half tank of gas. Then starting from a full tank, you slowly approach "perfect" alignment the more gas you consume. After you pass the half way mark, you start falling further away from your perfect alignment again... Maybe it doesnt work this way... I dont know.

It does seem a bit **** to me. After a I go over a couple of bumps or pot holes in the city, the alignment is probably off anyways.