[Nexus313]

Hi guys, I just got allignment today after a week of installing my h&r springs. Here are the specs. It looks like my front left camber is slightly off. From my understanding you can't adjust it on these cars. Is something potentially wrong with my strut mount or lower control arms?

[FaRKle!]

There's a small amount of play in the bolt that mounts the LCA/Wishbone to the subframe. The only way to really adjust camber is to try and pull/push the bolt to the edge of the play it has and clamp it there. I don't think you'll get more than 0.1 or 0.2deg that way though.

I recommend dialing less toe (0.05deg in each side, front and rear), and less rear camber (-1deg both sides). It'll make the car feel a lot more nimble.

[Nexus313]

Originally Posted by FaRKle!

There's a small amount of play in the bolt that mounts the LCA/Wishbone to the subframe. The only way to really adjust camber is to try and pull/push the bolt to the edge of the play it has and clamp it there. I don't think you'll get more than 0.1 or 0.2deg that way though.

I recommend dialing less toe (0.05deg in each side, front and rear), and less rear camber (-1deg both sides). It'll make the car feel a lot more nimble.

Well, I don't necessarily want more negative camber up front since I'm xDrive.. isn't -1.4 camber on the front left a bit excessive? The OE spec shows -0.3 to -0.5 .. I understand lowering springs give it more negative camber but almost -1 degrees more? Is it normal? I don't wanna blow an axle since i'm on xDrive.

Hmm you're right, I'm going to see if I can get less toe and camber, as the steering feels alot more vague than before I went into the alignment. I'm assuming a bit less toe and rear camber will make the steering a bit more tighter? Shouldn't the toe be slightly higher in the rear than front?

[DreamerJoe]

Originally Posted by FaRKle!

There's a small amount of play in the bolt that mounts the LCA/Wishbone to the subframe. The only way to really adjust camber is to try and pull/push the bolt to the edge of the play it has and clamp it there. I don't think you'll get more than 0.1 or 0.2deg that way though.

I recommend dialing less toe (0.05deg in each side, front and rear), and less rear camber (-1deg both sides). It'll make the car feel a lot more nimble.

will adjusting the rear camber have any other adverse effects? it seems too small to create bad tread wear, but mainly straight line traction? or it will behave the same? crazy story, few years ago I bought a G35 that was lowered by the previous owner and when I checked the tires they felt fine, I didn't feel the very inside edge, but the rest of the tire.. ended up having a blow out doing 80mph and had to replace both back tires. lucky I didn't crash or damage my quarter panel.

[FaRKle!]

Originally Posted by Nexus313

Well, I don't necessarily want more negative camber up front since I'm xDrive.. isn't -1.4 camber on the front left a bit excessive? The OE spec shows -0.3 to -0.5 .. I understand lowering springs give it more negative camber but almost -1 degrees more? Is it normal? I don't wanna blow an axle since i'm on xDrive.

Hmm you're right, I'm going to see if I can get less toe and camber, as the steering feels alot more vague than before I went into the alignment. I'm assuming a bit less toe and rear camber will make the steering a bit more tighter? Shouldn't the toe be slightly higher in the rear than front?

The OE specs are designed for understeer and straight tracking when there's no hands on the wheel. These cars gain a lot of grip in the corner when going to more negative camber in the front. -1.4deg isn't excessive at all, and the M3/4 nominal front negative camber is -1.5deg. If you had the choice to lower the -1.4deg to -1.0, or increase the -1.0 to -1.4, I'd do the increase from -1.0 to -1.4.

Now regarding popping axles, that depends on how low you are. I ran -1.5deg up front no problems with a mild lowering with xDrive (about .5"). Folks that have popped axles were lowering much more, like 1" or greater IIRC.

Toe doesn't need to be higher in the rear than front. It just has to be enough to keep the rear end straight on acceleration. IME 0.05deg in each side is enough to keep the car tracking straight. If you're really worried about it though you can go 0.08 or 0.1deg in each side for the rear. Toe is what causes the most tire wear though (more than camber).

Originally Posted by DreamerJoe

will adjusting the rear camber have any other adverse effects? it seems too small to create bad tread wear, but mainly straight line traction? or it will behave the same? crazy story, few years ago I bought a G35 that was lowered by the previous owner and when I checked the tires they felt fine, I didn't feel the very inside edge, but the rest of the tire.. ended up having a blow out doing 80mph and had to replace both back tires. lucky I didn't crash or damage my quarter panel.

No adverse effects from adjusting rear camber. What we're actually doing is removing a bit of rear cornering grip so it's better balanced with the amount of front grip the car has to reduce large understeer. If the front had more negative camber (and thus cornering grip), then we'd leave the more negative rear camber in place.

[Nexus313]

Originally Posted by FaRKle!

The OE specs are designed for understeer and straight tracking when there's no hands on the wheel. These cars gain a lot of grip in the corner when going to more negative camber in the front. -1.4deg isn't excessive at all, and the M3/4 nominal front negative camber is -1.5deg. If you had the choice to lower the -1.4deg to -1.0, or increase the -1.0 to -1.4, I'd do the increase from -1.0 to -1.4.

Now regarding popping axles, that depends on how low you are. I ran -1.5deg up front no problems with a mild lowering with xDrive (about .5"). Folks that have popped axles were lowering much more, like 1" or greater IIRC.

Toe doesn't need to be higher in the rear than front. It just has to be enough to keep the rear end straight on acceleration. IME 0.05deg in each side is enough to keep the car tracking straight. If you're really worried about it though you can go 0.08 or 0.1deg in each side for the rear. Toe is what causes the most tire wear though (more than camber).



No adverse effects from adjusting rear camber. What we're actually doing is removing a bit of rear cornering grip so it's better balanced with the amount of front grip the car has to reduce large understeer. If the front had more negative camber (and thus cornering grip), then we'd leave the more negative rear camber in place.

Ok, got it! This is some really useful information.. but what are your thoughts on the 0.4 degree difference between L/R front camber? Is it normal to have a difference that high? Or do you think there's an underlying issue with one of my LCA/ Strut mounts?

Regarding axle popping, I'm 1.6" lower front, 1.5" in the back. H&R sport springs for xDrive

[FaRKle!]

Originally Posted by Nexus313

Ok, got it! This is some really useful information.. but what are your thoughts on the 0.4 degree difference between L/R front camber? Is it normal to have a difference that high? Or do you think there's an underlying issue with one of my LCA/ Strut mounts?

Regarding axle popping, I'm 1.6" lower front, 1.5" in the back. H&R sport springs for xDrive

0.4deg difference isn't ideal, but it's within BMW specifications (they allow up to 0.5deg difference). If you can get it down to within 0.2deg that'd be nice.

I wouldn't go greater than -1.4deg negative camber given your drop amount. The risk is exacerbated if your LCAs are pointing up at static height (knuckle end of the LCA is higher than the subframe end).

[Nexus313]

Originally Posted by FaRKle!

0.4deg difference isn't ideal, but it's within BMW specifications (they allow up to 0.5deg difference). If you can get it down to within 0.2deg that'd be nice.

I wouldn't go greater than -1.4deg negative camber given your drop amount. The risk is exacerbated if your LCAs are pointing up at static height (knuckle end of the LCA is higher than the subframe end).

Yeah I was looking at the document and 0.5 deg difference does seem excessive even though they recommend it.. I actually want it to be -1 to -1.2 on the left side somehow.. maybe we can mess with that bolt you mentioned..

My alignment guy is saying that if I go -1 camber in the back my tires will be toast by winter.. hmmm I'm having trouble believing that.

[FaRKle!]

Originally Posted by Nexus313

My alignment guy is saying that if I go -1 camber in the back my tires will be toast by winter.. hmmm I'm having trouble believing that.

That makes no sense at all. It'll actually have more even tread wear there during normal driving. The reason you go to more negative camber is for more grip in hard cornering.

[Nexus313]

Originally Posted by FaRKle!

That makes no sense at all. It'll actually have more even tread wear there during normal driving. The reason you go to more negative camber is for more grip in hard cornering.

Yeah .. I guess it's time to change to another alignment guy!

[Nexus313]

Sooo yeah the steering feels super light and vague compared to pre-alignment.

If I go 0.05 on the toe each side, will it cause accelerated tire wear?

[FaRKle!]

Originally Posted by Nexus313

Sooo yeah the steering feels super light and vague compared to pre-alignment.

If I go 0.05 on the toe each side, will it cause accelerated tire wear?

It'll reduce wear. The more toe in or out you have, the greater the wear. So by making the toe closer to straight ahead you'll reduce the wear. What you should shoot for is the least amount of toe in needed so the car tracks straight, which is about 0.05deg in on each side IME.

[Nexus313]

Originally Posted by FaRKle!

It'll reduce wear. The more toe in or out you have, the greater the wear. So by making the toe closer to straight ahead you'll reduce the wear. What you should shoot for is the least amount of toe in needed so the car tracks straight, which is about 0.05deg in on each side IME.

So you're telling me.. If I go slightly more positive camber in the back and less toe, not only will I get better handling, but I'll also get reduced tire wear? What I'm I waiting for then! How come BMW doesn't recommend this setup config though?

Is there any downsides at all to this configuration? And is it how you are running it aswell?

[FaRKle!]

Originally Posted by Nexus313

So you're telling me.. If I go slightly more positive camber in the back and less toe, not only will I get better handling, but I'll also get reduced tire wear? What I'm I waiting for then! How come BMW doesn't recommend this setup config though?

Is there any downsides at all to this configuration? And is it how you are running it aswell?

Yes, you'll get better tire wear and handling. BMW doesn't tune it this way for liability reasons as I mentioned in post #5.

Since I track my car, and have hardware that gives me more adjustability, my numbers are different for camber (I run -2.5deg front and -1.7deg rear), but I tune my toe the same (0.05deg in each side for the front and 0.05 to 0.1deg in on the rears). You can see it's in the same spirit/ideology as what I told you. Before I started tracking the car I aligned it the same as what I recommended to you.

The only downside is if you're driving to the tires' limits like autocross of HPDEs the overall rear grip will be less. This shouldn't be an issue daily driving or "fun canyon" driving.

[Nexus313]

Originally Posted by FaRKle!

Yes, you'll get better tire wear and handling. BMW doesn't tune it this way for liability reasons as I mentioned in post #5.

Since I track my car, and have hardware that gives me more adjustability, my numbers are different for camber (I run -2.5deg front and -1.7deg rear), but I tune my toe the same (0.05deg in each side for the front and 0.05 to 0.1deg in on the rears). You can see it's in the same spirit/ideology as what I told you. Before I started tracking the car I aligned it the same as what I recommended to you.

The only downside is if you're driving to the tires' limits like autocross of HPDEs the overall rear grip will be less. This shouldn't be an issue daily driving or "fun canyon" driving.

Perfect, thanks. Appointment booked for Thursday at a different alignment place (One that specializes in lowered cars and custom alignments, rather than slapping up OE specs.)

Will let you know how it goes with your recommendation. Maybe ill make a post for others who put H&R on since I couldn't find this info PRE-allignment haha.

[Nexus313]

Here's my new alignment spec. Feels ALOT better .. decided to go with the 0.07-0.08 range for toe in the rear just to be safe. As for the rear camber, it maxed out at -1.16/-1.18 and wouldn't go lower to -1.

Turns out the first guy who did my alignment, the numbers on his sheet were totally wrong in comparison to when the car went onto a different alignment rack. Toe was all out of wack.