[kern417]

Yep. to thisismikeyb point, lowering does nothing other than sit the car lower within the suspension's standard travel. The arc doesn't change. Any time you go over big bumps or load the suspension around turns, you're "lowering" your suspension on that side. So unless people are popping axles at track days and autox, lowering isn't the issue.

[FaRKle!]

Originally Posted by thisismikeyb

Actually that's exactly what I am think, the two pictures of my car I posted show exactly that, one I have a good amount of fender gap, the other I have none. My camber would have to change as the suspension gets compressed to tuck the tire under the fender. I would think heavy braking and turning into corners you're putting a substantial load on your front suspension, which should far exceed that 1.6" drop by H&R.

All I'm really saying is if you dropped your down to SoCalCarGuy's level, I would think your front camber would be more aggressive.

Originally Posted by kern417

Yep. to thisismikeyb point, lowering does nothing other than sit the car lower within the suspension's standard travel. The arc doesn't change. Any time you go over big bumps or load the suspension around turns, you're "lowering" your suspension on that side. So unless people are popping axles at track days and autox, lowering isn't the issue.

But the camber across the arc is different for two different cars at two different ride heights that are aligned to the same camber at those two different ride heights. If that weren't true then it means you'd be able to maintain the same camber throughout the arc, which we know isn't true.

[kern417]

Originally Posted by FaRKle!

But the camber across the arc is different for two different cars at two different ride heights that are aligned to the same camber at those two different ride heights. If that weren't true then it means you'd be able to maintain the same camber throughout the arc, which we know isn't true.

Agreed. But what I'm saying is, for your car specifically, lowering it 1/2" is no different than going over a speed bump or taking a hard turn that compresses the suspension 1/2". You're locking it down in a place that it's already free to travel to (and through) with the stock suspension.

That changes significantly when you adjust your control arms, because now the camber gain is different. Especially if your roll center moves. Adjusting with camber plates won't have the same effect to your dynamic handling regardless of ride height. You're only really changing your static camber to compensate for a crappy camber curve.

[motoring_101]

Originally Posted by kern417

Agreed. But what I'm saying is, for your car specifically, lowering it 1/2" is no different than going over a speed bump or taking a hard turn that compresses the suspension 1/2". You're locking it down in a place that it's already free to travel to (and through) with the stock suspension.

That changes significantly when you adjust your control arms, because now the camber gain is different. Especially if your roll center moves. Adjusting with camber plates won't have the same effect to your dynamic handling regardless of ride height. You're only really changing your static camber to compensate for a crappy camber curve.

I agree with what you are saying in that lowering your car only puts the suspension into a compressed position that it achieves when cornering hard.

However by lowering you are putting it there all the time including when you have a lot or even full lock on and putting power through the driveshafts

You would very rarely, if ever, have the suspension compressed, more than half a turn of lock and introduce full power in normal driving. When going through fast corners it is surprising how little steering lock you actually need.

I can see how a combination of lowering and camber adjustment through bushings or M3 arms could be an issue, although it seems the M3 arms are enough on their own! I would probably shy away from camber adjusting bushes after reading this and stick to lowering plus Camber plates and/or correction hubs.

I thought the whole reason the x-drive has SE springs is because Msport springs were too low for the CV joints in BMW's view?

[thisismikeyb]

Originally Posted by FaRKle!

But the camber across the arc is different for two different cars at two different ride heights that are aligned to the same camber at those two different ride heights. If that weren't true then it means you'd be able to maintain the same camber throughout the arc, which we know isn't true.

You keep repeating the same statement, which no one is disagreeing with, and you don't seem to understand what I'm saying, I will try to elaborate.

If your car started at -0.6 degrees of camber, to achieve -1.8 degrees you would have to dial in -1.2 degrees, which you did by effectively lengthen your LCA.

SoCalCarGuy's car started at -0.7 degrees of camber because he is lower, to achieve that same camber he only had to add -1.1 degrees, which means his LCA should effectively be shorter than yours.

With that in mind, if you were to lowered your car to match, and used the same LCA setting you have now, I'm guessing your front camber would be closer to -1.9 degrees. Since the lower your car goes, the more negative camber you get. Which should be the same effect when you are taking corners at the track, and compressing your front suspension. Your front axles should be further stretched due to your LCA's being longer.

Additionally, there probably is not enough suspension travel to cause a situation where SoCalCarGuy's front hub extend past yours. This again is because your LCA should effectively longer than his. Which would mean his front wheels should not be pushed out as far, and his camber arc should be inside your camber arc. ie: less aggressive.

Now the other common thing between Kies' 335ix and SoCalCarGuy's 440ix is they are both I6's, which as we know are inherently balanced by design. Could it be due to the I4's needing to have balanced crank shafts, that the lower portion of the block is wider to accommodated that? This currently is my theory to why you have not had an axle fail, but SoCalCarGuy and Kies did.

Finally, you might want to put a disclaimer on your thread where you initially reported getting -1.8 degrees of camber using these bushings. Don't need anyone else breaking axles on the forums until the root cause is found.

[FaRKle!]

Originally Posted by thisismikeyb

You keep repeating the same statement, which no one is disagreeing with, and you don't seem to understand what I'm saying, I will try to elaborate.

If your car started at -0.6 degrees of camber, to achieve -1.8 degrees you would have to dial in -1.2 degrees, which you did by effectively lengthen your LCA.

SoCalCarGuy's car started at -0.7 degrees of camber because he is lower, to achieve that same camber he only had to add -1.1 degrees, which means his LCA should effectively be shorter than yours.

With that in mind, if you were to lowered your car to match, and used the same LCA setting you have now, I'm guessing your front camber would be closer to -1.9 degrees. Since the lower your car goes, the more negative camber you get. Which should be the same effect when you are taking corners at the track, and compressing your front suspension. Your front axles should be further stretched due to your LCA's being longer.

Additionally, there probably is not enough suspension travel to cause a situation where SoCalCarGuy's front hub extend past yours. This again is because your LCA should effectively longer than his. Which would mean his front wheels should not be pushed out as far, and his camber arc should be inside your camber arc. ie: less aggressive.

This is where I disagree with you. With a Macpherson strut as you get more compression/lowering and the LCA goes up past parallel to the ground (so it has a upward angle from the body to the knuckle) the camber actually decreases (you can see some simulations of this here and here). This is why we try to run as much static camber as possible, to mitigate the loss on compression when going around a turn. It's also why Macpherson strut cars like ours typically benefit from a stiff front sway bar, because it minimizes the roll, and thus negative camber loss.

When I look at my suspension as it currently sits (I'm lowered by 5.5mm, a bit less than 1/4") my LCA is angled just slightly below being parallel to the ground. At a lowered amount that the H&R springs give, the LCA is very likely already pointing at an upward angle. Therefore, when my suspension is under compression, and the LCA is at the same angle as SoCalCarGuy's, my camber is less than -1.8deg, and my arm length is shorter.

Originally Posted by thisismikeyb

Now the other common thing between Kies' 335ix and SoCalCarGuy's 440ix is they are both I6's, which as we know are inherently balanced by design. Could it be due to the I4's needing to have balanced crank shafts, that the lower portion of the block is wider to accommodated that? This currently is my theory to why you have not had an axle fail, but SoCalCarGuy and Kies did.

The block widths could potentially be different, but it also looks like BMW makes up for that with different supporting bracket PNs. Note that the I6 and I4 gas engines use the same bracket (and the I4/6 diesels also use the same as each other). I would think if that was significant they'd have multiple axle lengths/versions, just like they do for rear axles.

[SoCalCarGuy]

Got my car back today.

Asides from the axle breaking ($1200), a mount on the transfer case broke ($140) and replacing the bushings with more stock original bushings ($60) + labor and alignment ($660)

shoutout to JMP autowerkz in Canoga Park

[thisismikeyb]

Originally Posted by FaRKle!

When I look at my suspension as it currently sits (I'm lowered by 5.5mm, a bit less than 1/4") my LCA is angled just slightly below being parallel to the ground. At a lowered amount that the H&R springs give, the LCA is very likely already pointing at an upward angle. Therefore, when my suspension is under compression, and the LCA is at the same angle as SoCalCarGuy's, my camber is less than -1.8deg, and my arm length is shorter.

You can not use the ground as a reference to how your LCA is aligned in your suspension. The strut is not perpendicular with the ground, and angled back in the car. If it was perpendicular with the ground all those people with flush fitments would be smashing their tires into their fenders.

[thisismikeyb]

Better yet, let me ask you a question FaRKle! , If you were to design a suspension for a car, at what point would you want maximum camber? This would be the point at which the LCA and Strut would form a 90 degree angle, which coincides with peak of the camber arc. I would put it at maximum point of compression of the suspension, wouldn't you? Last thing I would want is for my car to start losing camber while it is under maximum cornering load. This also means at any point in the camber arc, the farther away from that point, you are losing camber.

[kern417]

Originally Posted by thisismikeyb

Better yet, let me ask you a question FaRKle! , If you were to design a suspension for a car, at what point would you want maximum camber? This would be the point at which the LCA and Strut would form a 90 degree angle, which coincides with peak of the camber arc. I would put it at maximum point of compression of the suspension, wouldn't you? Last thing I would want is for my car to start losing camber while it is under maximum cornering load. This also means at any point in the camber arc, the farther away from that point, you are losing camber.

That only works with dual a-arms. with our mcpherson strut suspension, as soon as your lower control arm goes above horizontal you're losing camber. That's why mcpherson suspension is not ideal for handling and wheel fitment. With our cars, you'll most likely move into positive camber under full compression around a turn. I've ran upwards of 3* on previous cars because 200tw tires had enough grip to push past 0 camber in an aggressive turn. That's why the flush guys run a lot of camber, because it will rub under compression without it.

You can also upgrade your swaybars to reduce how much each side will compress in a hard turn.

[FaRKle!]

Originally Posted by thisismikeyb

You can not use the ground as a reference to how your LCA is aligned in your suspension. The strut is not perpendicular with the ground, and angled back in the car. If it was perpendicular with the ground all those people with flush fitments would be smashing their tires into their fenders.

Originally Posted by thisismikeyb

Better yet, let me ask you a question FaRKle! , If you were to design a suspension for a car, at what point would you want maximum camber? This would be the point at which the LCA and Strut would form a 90 degree angle, which coincides with peak of the camber arc. I would put it at maximum point of compression of the suspension, wouldn't you? Last thing I would want is for my car to start losing camber while it is under maximum cornering load. This also means at any point in the camber arc, the farther away from that point, you are losing camber.

Your presumption here is that if the strut is angled inward towards the car, that the max camber should be achieved when the strut and LCA are orthogonal to each other. This would be true if the strut was a solid member with a pivot point where it mounts to the shock tower, however it's variable length, so lateral distance away from the car when the LCA is parallel to the ground is what determines the max camber.

There's a difference between what we want and what "is." As kern417 mentioned, the dual wishbone/A-arm design achieves what you want with increasing camber as the suspension is compressed. Why wasn't that designed in from the get go? Cost. Macpherson struts are cheaper, which is a big reason why they're more common.

Also remember that as the height of the car is raised (say to OE levels) the LCA is pointing more downward, so in its arc it has more travel where camber is increased up to the parallel to ground LCA position. Of course there are other vehicle factors at play that detract from cornering ability when OE height is set, so the camber curve gain may be negated. As far as design goes, this may be a reason why BMW uses such long bump stops. We already know they engage pretty early, and are used as a device to try and slow/limit roll since they add to the spring rate. Maybe they're used to try and limit how compressed a side gets so the LCA doesn't enter the part of the arc where camber loss is high (or what BMW considers high/not acceptable).

[kern417]

Originally Posted by FaRKle!

Also remember that as the height of the car is raised (say to OE levels) the LCA is pointing more downward, so in its arc it has more travel where camber is increased up to the parallel to ground LCA position. Of course there are other vehicle factors at play that detract from cornering ability when OE height is set, so the camber curve gain may be negated. As far as design goes, this may be a reason why BMW uses such long bump stops. We already know they engage pretty early, and are used as a device to try and slow/limit roll since they add to the spring rate. Maybe they're used to try and limit how compressed a side gets so the LCA doesn't enter the part of the arc where camber loss is high (or what BMW considers high/not acceptable).

Everything I've read indicates that BMW leans heavily on camber and castor to create the steering feel and dynamics they're known for. That's less now being as they tend to push for understeer/safer driving characteristics, but easily achieved with aftermarket hardware. On my X5, the handling is incredibly surprising and i believe it's 100% because of the front suspension geometry with upper and lower control arms. The weight is hidden by the front end traction when taking big sweeping turns because the suspension does not compress much and there isn't a lot of body roll. The only downside is that it's not as compliant as say an audi or merc SUV. And you can only fit a 255 tire up front before things start hitting eachother under the fenders, which isn't that much for such a large vehicle.

[SoCalCarGuy]

https://f30.bimmerpost.com/forums/sh...4#post25150764

selling my set of K-Mac bushings

[Logicoeur]

Wondering why people here don't opt for camber plates more often? Is there something I'm not aware of when running those??

[andino]

Originally Posted by Logicoeur

Wondering why people here don't opt for camber plates more often? Is there something I'm not aware of when running those??

Typically the added noise. There's only a small bit of NVH, if any with using an LCA camber bushing.

[skier_du]

Originally Posted by andino

Typically the added noise. There's only a small bit of NVH, if any with using an LCA camber bushing.

That's true. But I've found the added NVH of camber plates is not nearly as bad as people think it's going to be. Especially if your suspension is fairly stock or has a soft setup. I added GC camber plates to my xDrive when I had the Powerflex race bushings replacing the rubber in the 2 front control arms, along with Bilstein B8 and Swift Spec-R springs on my car. My wife is sensitive and never even noticed the difference. Only thing I felt was a little better steering response and a little more connected to what the front tires are doing on the road. Personally, I think if anyone is on the edge of whether or not to get camber plates, it's completely worth it.
Regarding the axles, this is my second xDrive 3 series and I've probably driven over 100k miles lowered between the 2 cars. Some has been with stock top hats. Some has been with camber plates. I've never had an axle problem. And my cars have been fairly low. Like almost tucked to slightly tucked low. The problem is definitely the lower bushings pushing the hubs out and thereby pulling the axle joints apart. Similar to adding the longer M3 lower control arms. Just avoid doing those camber bushings. That way the axles should be able to stay within the designed range. And anyone should be fine as long as there's not other problems.

[EDWYER]

Originally Posted by kern417

Yep. to thisismikeyb point, lowering does nothing other than sit the car lower within the suspension's standard travel. The arc doesn't change. Any time you go over big bumps or load the suspension around turns, you're "lowering" your suspension on that side. So unless people are popping axles at track days and autox, lowering isn't the issue.

Agreed, no issues after 10K on my dinan's.

[andino]

Originally Posted by skier_du

That's true. But I've found the added NVH of camber plates is not nearly as bad as people think it's going to be. Especially if your suspension is fairly stock or has a soft setup. I added GC camber plates to my xDrive when I had the Powerflex race bushings replacing the rubber in the 2 front control arms, along with Bilstein B8 and Swift Spec-R springs on my car. My wife is sensitive and never even noticed the difference. Only thing I felt was a little better steering response and a little more connected to what the front tires are doing on the road. Personally, I think if anyone is on the edge of whether or not to get camber plates, it's completely worth it.
Regarding the axles, this is my second xDrive 3 series and I've probably driven over 100k miles lowered between the 2 cars. Some has been with stock top hats. Some has been with camber plates. I've never had an axle problem. And my cars have been fairly low. Like almost tucked to slightly tucked low. The problem is definitely the lower bushings pushing the hubs out and thereby pulling the axle joints apart. Similar to adding the longer M3 lower control arms. Just avoid doing those camber bushings. That way the axles should be able to stay within the designed range. And anyone should be fine as long as there's not other problems.

It was pretty night and day when I swapped out my camber plates from stock with b14s. A lot more road noise is transmitted to the car on rough roads. Its particularly bad on freeways around SF but I like the performance gain so I live with it for now. Everyone's tolerance may be different so I usually suggest those interested about camber plates but are also concerned about noise to go for a ride in a car with pillowball or camber plates so they can hear for themselves how much is transmitted into the cabin.

[skier_du]

It's true there are different tolerances for people. But I'd hardly say it was a huge difference in NVH. To me it was like a 10% or slightly more increase. I didn't find I had to start rasing my voice in the car to have a conversation. Much less mild than a down pipe or slightly aggressive exhaust for noise. Little vibration more through the steering wheel. Which can be good for starting to get some road feel back in the car. Vibrations weren't enough for me to feel through the seats. But there are other factors like tires and which shocks or springs and which plates you use.

[kern417]

Originally Posted by skier_du

It's true there are different tolerances for people. But I'd hardly say it was a huge difference in NVH. To me it was like a 10% or slightly more increase. I didn't find I had to start rasing my voice in the car to have a conversation. Much less mild than a down pipe or slightly aggressive exhaust for noise. Little vibration more through the steering wheel. Which can be good for starting to get some road feel back in the car. Vibrations weren't enough for me to feel through the seats. But there are other factors like tires and which shocks or springs and which plates you use.

The NVH is specific based on the component. It didn't make more engine noise, but you definitely hear road noise more. It can also cause metallic noises as the bearings wear.

[skier_du]

I do agree, there is an increase in road noise. Just not so much it makes the drive unbearable. But, like we said, each person has their own version of what is unbearable to them.
You also bring up another point, camber plates bring more maintenance. If you leave them on year round, the bearings will wear faster. And make more noise as a result. I put new bearings in mine this spring for that very reason. I don't mind because it they don't cost much and I can change them in just a few hours, start to finish. But if you don't do your own work it would be a costly maintenance to pay someone to change them every year or so, and an inconvenience. Definitely something to consider.