Alignment settings

[shimmy09]

Im taking my car for alignment next week... Need help with alignment settings, my car is dropped on kw v3.. What alignment spec would be good for mostly street driving also looking to save my tires... Thanks

[Shipkiller]

What do you want to do with your car? Street/Track/Autocross? or just street?

[Finnegan]

I think he wants street with minimal wear no autox or track.

If so, Ship, what about these settings:

Front -1.00 (if "aggressive street and cornering" then -1.5) and 1/32 toe in (if he wants something a bit better for straight line stability, maybe 1/16 toe in, but there's a marginal amount more wear due to toe with that)

Rear: -1.6 with 1/32 toe in

With a lowered car getting that little negative camber may be tough though. I'd expect it would be difficult to come in less than -1.5 up front and -1.9 rear....and if so, I'd go with minimum tolerable toe in up front (1/32 or even zero, knowing that zero will require attention by the driver since the car will be want to wander a bit more). Toe IMO is harder on tires than negative camber, unless it's a heck of a lot of negative camber.

For an alternate setting, since mine is used on track a lot, I'm having it aligned tomorrow with:

Front -2.5 (more aggressive track only would be -3.0) and zero toe

Rear: -1.8 with 1/32 toe in

I want to still be able to rotate the rear and I think too much negative camber might be counterproductive....

[Shipkiller]

If it was me and I just wanted a street setting with minimal wear, then I would just stay with the stock BMW settings. The stock settings from BMW are good for this.

[BTM]

Mine are

F
-2.2 Camber
.05 toe in

R
-1.8 Camber
0 toe

I like it but will dial in a little more negative camber up front next time and probably .05 toe in rear as having 0 toe is really eating up rear tires fast...

[l4zy]

does 0 toe really cause the tires to wear faster? i figured if the wheels are straight wear should be minimized.

[BTM]

with zero toe they will scrub more...the force of going forward "pushes" the tires "out" if you can visualize that. It rotates better because of this, but when the tires are pointing slightly inward, the force of going forward causes them to straighten out, and this reduces wear on them

perhaps tirerack says it better "A rear-wheel drive vehicle "pushes" the front axle's tires as they roll along the road. Tire rolling resistance causes a little drag resulting in rearward movement of the suspension arms against their bushings. Because of this, most rear-wheel drive vehicles use some positive toe-in to compensate for the movement, enabling the tires to run parallel to each other at speed.

Additionally the vehicle's toe is one of the most critical alignment settings relative to tire wear. A toe setting that is just a little off its appropriate setting can make a huge difference in their wear. Consider that if the toe setting is just 1/16-inch off of its appropriate setting, each tire on that axle will scrub almost seven feet sideways every mile! Extend it out and you'll discover that rather than running parallel to each other, the front tires will scrub over 1/4-mile sideways during every 100 miles of driving! Incorrect toe will rob you of tire life."

[l4zy]

Ah I see! I never considered that! Thanks for the explanation.

[The HACK]

Bmw's oem alignment settings are actually a compromise between handling and wear. If you want less wear you should minimize the rear camber. I'd go -0.7 up front (the low end of factory setting) and as little as you can manage in the rear. If you can get to around -1 degree in the rear you should extend tire life significantly. Toe in slightly (no more than 1/16" total) and you should have decent tire life. Compensate the lack of camber with a grippier tire like the new Michelin Pilot Super Sport and you have the best of all world...a car that should handle well with the stickier tires, and the tire SHOULD last significantly longer than stock alignment.

[wassup61]

Originally Posted by The HACK

Bmw's oem alignment settings are actually a compromise between handling and wear. If you want less wear you should minimize the rear camber. I'd go -0.7 up front (the low end of factory setting) and as little as you can manage in the rear. If you can get to around -1 degree in the rear you should extend tire life significantly. Toe in slightly (no more than 1/16" total) and you should have decent tire life. Compensate the lack of camber with a grippier tire like the new Michelin Pilot Super Sport and you have the best of all world...a car that should handle well with the stickier tires, and the tire SHOULD last significantly longer than stock alignment.

LOL... have fun with that alignment

[cgroppi]

Originally Posted by The HACK

Bmw's oem alignment settings are actually a compromise between handling and wear.

If by "handling" you mean making the car understeer

[krnnerdboy]

how does toe settings for the rear correlate to car handling? I know that front toe out gives better turn-in and toe-in for better highspeed stability and less tracking....

[cgroppi]

Originally Posted by krnnerdboy

how does toe settings for the rear correlate to car handling? I know that front toe out gives better turn-in and toe-in for better highspeed stability and less tracking....

Toe-in in the rear makes the rear end more stable under power, but also results in steady state understeer, and if too extreme makes it too hard to induce and control power oversteer. Lots of rear camber (relative to the front, anyway), increases rear grip under cornering load, which can also induce understeer. The OEM alignment for the rear on a Z4M has both: lots of rear toe in and lots of negative camber.

I cut both the toe and camber in half in the back, and may remove even more depending on how much grip I can ultimately get in front.

[BTM]

Have you tried playing with some toe out in front. As I alluded to before with 0 toe in rear ate up tires too fast for my liking...so next gonna put a little toe in rear and a little more negative camber/toe out in front. That combined with bigger front tires on this set should hopefully keep the understeer at bay

[cgroppi]

Yes, I have about 1/4" total toe out in the front. That's one of the first things I did, along with maxing out the front camber. I compete in stock class, so I can't use shims or camber plates. I have 285s in front, which also help .

[Shipkiller]

Originally Posted by cgroppi

Yes, I have about 1/4" total toe out in the front. That's one of the first things I did, along with maxing out the front camber. I compete in stock class, so I can't use shims or camber plates. I have 285s in front, which also help .

How do you fit 285's in the front of the car? The most I has seen/heard of is 255's in the front.

What is the secret?

[BTM]

Originally Posted by Shipkiller

How do you fit 285's in the front of the car? The most I has seen/heard of is 255's in the front.

What is the secret?

+1

[cgroppi]

Originally Posted by Shipkiller

How do you fit 285's in the front of the car? The most I has seen/heard of is 255's in the front.

What is the secret?

Stock struts (actually Koni DAs with stock springs), stock wheels, and 285/30 Hoosier A6s, which are 1" smaller diameter than stock. The stock wheels (which are required by rule) squeeze the tires, which helps a little. The OEM style struts have the spring up high, so the tire doesn't have to clear the spring and perch like it does with coilovers., just the strut body. The smaller diameter tires make sure the fender liners clear. I needed 5mm spacers in the rear (same size tire on stock 18x9s) to clear the fender liner, but that's it.

Getting the same tires to clear mounted on 18x10s with coilovers would require a lot more work, but as it stands, I didn't have to do anything other than the rear spacers.

Here's a link to another post with a picture:

http://www.zpost.com/forums/showpost...5&postcount=23

[The HACK]

Originally Posted by wassup61

LOL... have fun with that alignment

OP is not looking to "track" the car, it's going to be mostly driven on street and he/she wanted to save tires. The settings I suggested will do just that, especially on this chassis.

I don't know why a slight toe-in in the rear is going to promote understeer. Toe-in in the rear improves high speed stability. Toe-out in the rear will promote quicker response to steering input. But understeer or oversteer states are mostly determined by available grip and toe settings does not affect that. Camber does.

As far as having fun with that setting? You can have a butt load of fun with that setting as long as your tires can provide the grip. For example, r-comps on that setting is going to handle better than all-seasons on an aggressive alignment setting. You can argue that r-comps on aggressive alignment will handle better, but that's not what OP was looking to do.

[wassup61]

Originally Posted by The HACK

OP is not looking to "track" the car, it's going to be mostly driven on street and he/she wanted to save tires. The settings I suggested will do just that, especially on this chassis.

I don't know why a slight toe-in in the rear is going to promote understeer. Toe-in in the rear improves high speed stability. Toe-out in the rear will promote quicker response to steering input. But understeer or oversteer states are mostly determined by available grip and toe settings does not affect that. Camber does.

As far as having fun with that setting? You can have a butt load of fun with that setting as long as your tires can provide the grip. For example, r-comps on that setting is going to handle better than all-seasons on an aggressive alignment setting. You can argue that r-comps on aggressive alignment will handle better, but that's not what OP was looking to do.

If OP does any sort of turning at all, the outside edges of those new sticky tires will be eaten up, not to mention, that getting -1.0 degrees of rear camber in an M coupe is near impossible, and very capable of generating snap oversteer in a situation where power is applied and weight is shifted to the outside wheel.

[The HACK]

Originally Posted by wassup61

If OP does any sort of turning at all, the outside edges of those new sticky tires will be eaten up, not to mention, that getting -1.0 degrees of rear camber in an M coupe is near impossible, and very capable of generating snap oversteer in a situation where power is applied and weight is shifted to the outside wheel.

That's a bit overly dramatic. I've driven my WRX on stock alignment at Laguna Seca and Buttonwillow and there's even less camber available on that car than what I suggested, and it didn't push off or roll over on the outer edge the second I tried to turn the wheel...Sure, there are more wear on the outer edge due to my activities on the track, and there isn't as much grip as I like (these are street tires after all...with UTQG 300 rating), but the OP clearly states that saving tires is one of the concerns and it will be primarily driven on the street.

So any sort of aggressive alignment setting will be purely a waste. It's like recommending a Breitling for a daily watch for a construction worker, or insist on eating a Ruth Chris filet mignon for a late afternoon snack, or recommending NT-01s for a Toyota Camry driven to and from work every day.

I'm just saying'...

[arggg45]

Originally Posted by The HACK

That's a bit overly dramatic. I've driven my WRX on stock alignment at Laguna Seca and Buttonwillow and there's even less camber available on that car than what I suggested, and it didn't push off or roll over on the outer edge the second I tried to turn the wheel...Sure, there are more wear on the outer edge due to my activities on the track, and there isn't as much grip as I like (these are street tires after all...with UTQG 300 rating), but the OP clearly states that saving tires is one of the concerns and it will be primarily driven on the street.

So any sort of aggressive alignment setting will be purely a waste. It's like recommending a Breitling for a daily watch for a construction worker, or insist on eating a Ruth Chris filet mignon for a late afternoon snack, or recommending NT-01s for a Toyota Camry driven to and from work every day.

I'm just saying'...

I don't know about you, but if I was offered a Ruth Chris filet mignon for a snack, I wouldn't turn it down...