So I've got an '09 AWD G37 lowered on Eibach Springs. Of course my camber, post lowering, is out of spec and every alignment 'expert' I talk to had recommended I get front and rear camber/toe kits to get within OEM specs. I finally went ahead and got the rear camber kit installed the other day when it finally dawned on me...

WHY IN THE WORLD AM I USING OEM ALIGNMENT SPECS FOR A LOWERED CAR?

It just makes no sense. The vehicle's dynamics are different. The center of mass is lowered. The car handles differently. Why the heck would I try to get within the factory recommended specs for a car that sits 1.5" lower than the car that said specs are recommended for? So, with this in mind, what SHOULD my alignment specs be set at? Logic dictates that I should not be at the recommended midpoint, and perhaps even outside the range altogether, but where, even approximately? At the end of the day, if I wanted a car that would give me OEM tire wear, OEM handling, and OEM stance, I would not have lowered the car in the first place. At the same time, however, I don't want to eat through a set of tires at 2x their normal rate of wear.

Thoughts?

 

Simple - If you want OEM tire wear, then you need OEM camber and toe.

 

Do you really think you'll get OEM tire wear just by following recommendations for a car on a different suspension? Those recommendations are for an OEM car.

But lets say I'm okay with slightly worse than OEM tire wear, and slightly better than OEM handling... where does that bring me?

 

Ok then, you tell me how you plan to get good, even tire wear with out of spec alignment that's inherent whenever you lower a car by at least a moderate amount?

Not quite sure what you mean by the second question. If you're fine with better handling at the expense of even tire wear, what's the problem? That's exactly what you'll get if you lower your car without alignment correction.

 

You'd still be outta spec on the toe and you'd want to get that fixed.

 

Yup out of spec toe will chew up your tires super quick. If u can get the toe in spec with the stock adjustment (and are fine with tire wear resulting from the out of spec camber), do it by all means.

 

The geometry of the steering and suspension has nothing to do with how the wheels should sit and where they should point. If anything, the only part of the alignment that shouldn't fall under OEM specs anymore is the caster, which changes by itself once you drop your car already. You can try to balance the feel of the turns out a bit by playing around with the camber, but either way, it's not a true fix to the f'd up geometry you now have by dropping the car.

Other than caster, alignment is more about how long you want your tires to last. Toe and camber can both affect performance, but it's all at the expense of the tire's life. Dropped or not, the alignment should be the same for a car depending on your own personal preferences.

 

This is exactly my point. I'd like to know how much camber I can add without chewing through a 540 treadwear rated tire in 20,000 miles yet not compromise handling too much.

I had -2.2 camber in the rear pre-alignment and drove out of the shop with -1.1, which is just a few tenths off center from OEM G37x specs (don't ask me why he was still not able to dial it in perfectly on-center even with a camber kit ). The car handles differently and that is not acceptable to me. I just wonder how much negative camber I should add. I drive aggressively, but the car is my daily driver, so I'm just trying to find the right balance between tire life and handling via the camber setting.

 

I'm willing to compromise some tire life for better handling. I'm interested in knowing how much an incremental change in camber affects tread wear. I guess it has not been quantified and I'll just need to play around with it each time I get alignment. Perhaps I'll add 10-20% to my current rear camber setting.

What about front camber? How do rear and front camber interact? Should one be lower than the other, especially on this car?

 

Ideally, I would want camber to be the same on both sides, especially when the car is moving... but add the weight of the driver, you'd want a little more camber on the passenger side. A subtle alignment for me would be about 2-4 degrees camber in the front, about 1-2.5 in the rears. But if your tires have such good treadwear, I'd question if they're even decent performing tires to begin with and are even worth getting a more aggressive alignment for as higher treadwear ratings means a harder compound with less grip, and tires are the most important component to the performance of the car.

 

Why do you advocate more camber in the front than in the rear?

Agreed.

 

Because the rear wheels propel the car while the fronts are for steering... if it was a FWD car, I'd do it the other way.

 

More front camber is correct.

If it was my car and I was running some NT05s, I'd run around -2 in the front and around -1.5 in the rear. Unfortunately, since I don't have front camber arm, and the offset for rear wheels are stupid, I'm running -2 in the front and -2.5 in the rear. I'm hoping to get some work done on the fenders real soon.

 

Blueslate, how is your tire wear with your negative camber? I dropped my car on tein htechs and the rears are at -2, im worried about tire wear. Toe is within specs though.

 

so camber and toe will eat up the tires? sorry for being a noob.