yam

Its been 2 months since I've lowered my car, and I finally got it aligned. Its now pulling very slightly to the right. It was straight prior to the alignment.

I had an alignment/subframe adjustment ($$$) done once before many months ago when I accidentally hit a pole while backing out with my wheel turned out in a parking stall. They ran out of subframe movement to get the full 0.5 deg different in caster. Also couldn't find anything bent or physically damaged. Thankfully, the tire hit flush on the pole flush, and I didn't have any body damage.

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The alignment took care of camber and toe issues, but now it pulls slightly to the right. The caster is not adjustable, left front camber is adjusted to the max. What are my options?

crew219

I'd be interested to see what they did for the caster adjustment. Given the numbers, there's no reason why the two numbers shouldn't be dead even.

Have you considered the pull to be due to tire wear?

Also, are you sure that they completely centered the wheel prior to doing the alignment? I've had a bad alignment before, where they didn't quite center the wheel.

Dave

yam

I'll try rotating, though, I've had two different sets of tires on since I've lowered it. The first alignment, they (Custom Alignment in Mt. View) had to move the subframe in order to get the caster back, and eliminate the pulling. After I got it back, they mentioned that they ran out of play on the subframe. Since I figured it would be a simple matter, I took it to a local shop to get it aligned this time. If it makes a difference, they used a hunter DSP400. Granted, it is a very slight pull currently. Steering wheel looks centered properly. I was hoping a camber/caster kit was available. I don't know if I want to sacrifice nvh with spherical bearings though.

crew219

Indicating that they could easily bring back whatever they adjusted in order to get the two values equal.

I think camber plates are going to be hard on the A5 platform given the very limited amount of room there is to perform any adjustments.

As for NVH . . . <a href="http://i32.photobucket.com/albums/d9/dmakca/A3/VF%20Mounts/IMG_1211.jpg">it is worth it :-)</a>

danham

Because your toe figures are shown in inches, degrees, and ? and it is usual for toe to be expressed as one number, not R and L numbers, I'm confused. Toe is the =difference= between L and R, not settings of L and R wheels.

Cars with excessive toe-out can "wander" or pull, but that doesn't appear to be the case here, though it's hard to tell.

I also don't know the A3 OEM specs off the top of my head. But all things being equal, a car with excessive negative camber will wear its tires which will cause handling weirdness such as pulling. Race cars run lots of negative camber for good handling, but replace tires frequently.

The side with the most caster is also the side to which the car will likely pull if it's going to pull at all. It's interesting that that would have been the left side until you lowered.

Finally, at the risk of insulting you, double check tire pressures and also consider road camber, which can simulate a pull to the right where one doesn't really exist.

-dan

yam

I have no idea how to convert the inches to degrees. That was just on the printout. No insult taken, I did check the air pressure prior to bringing it in. I filled up to factory spec at 41 front, 38 rear.

Total toe is currently at 0.15deg.

I think I want more caster to the right to compensate for the road crown. Is this correct?

From the Bentley...
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yam

Shooting for 0.5 deg difference to compensate for this.

danham

It's been some years since I crawled under the Bosch optical alignment ramp [g], so I'm rusty on this stuff, but the Bentley specs (thanks) appear to favor a tad of negative camber on the sporty suspenders, which would "go with" some positive caster.

Unless I'm rusty/confused/just plain wrong, you actually want LESS caster on the right to compensate for crown. Or more accurately, if the two sides differ within the allowed deviation, put the positive caster side of the "error" on the left wheel if possible.

Also, the specs appear to favor toe-in (not surprisingly), so they're suggesting that the best compromise between handling/tracking (at 10 minutes of arc toe-in) and tire wear (zero) is at 5'.

I now see that the separate L-R specs are to limit the amount of adjustment range for any one wheel to achieve the correct total toe-in (though a gross error would result in a badly mis-aligned steering wheel). Put another way, if you need to re-center the steering wheel after an alignment, something is bent or you did a lousy alignment [g].

One big disclaimer/factor is that we were taught at Porsche school to always set the ride height first (torsion bars in front). If that is off, adjusting the rest is just chasing yourself in circles. So a modified suspension may need to play by different rules here.

-dan

danham

Yes, but as per above I believe it will pull toward MORE caster.

We were taught not to align for road crown. Find a flat spot and check for pull. There should be none. Then if it pulls a tiny bit on slight crowns, leave it alone and/or run 1-2 psi more air in the RF tire if it bothers you.

-dan

yam

I'll wait and see how bad it is with 18x8's, and go from there.