[BMWM.D.]

This has probably been done and covered before, but I figured I'd share my results for anyone considering changing to any M3 suspension parts. Here it goes....

I personally aligned my E90 335i about a month ago on our brand new Hunter/BMW KDS alignment machine. The car has under 25k miles and everything looked as it should, so I set the rear camber and front/rear toe to BMW's specifications:

rear camber: -1 50' (1 degree & 50 minutes)
rear toe: 18'
front toe: 14'
Caster (not adjustable) : 7 05' / 7 00'

What I didn't like was my front camber:

left: - 14' (-.23 degrees)
right: -31' (-.51 degrees)

That's right around 1/4 degree negative on the left and 1/2 degree negative on the right for you guys that don't use the minute system. This is my second E90 335i, and the first one I had (same year/model) started showing wear on the outside shoulders of the front tires. There were actually almost bald when I traded that car in with only 17k miles. The rest of the tire looked great.

Anyway, I decided I wanted some more negative camber on this car. Besides possibly evening out the front tire wear for the way I drive, it should improve front end grip and reduce understeer. I see that as win-win. Since I don't like removing the strut locating pin to make adjustments, I decided to try the M3 control arms, or wishbones as BMW calls them.

Since I really don't have any complaints with the ride quality and handling of this car, I decided to not replace the tension struts -- just the 2 lower front control arms and the needed headlight sensor link. The install was very quick and I'm quite happy with how it came out. Since I had just aligned this car on this same alignment machine about a month ago, I think I got a very accurate idea of what should be gained by just changing these arms.

Results:

First, let me say that doing this threw my front toe MAJORLY out of whack. It was bad just driving it through the shop to the alignment bay. The tires were scrubbing badly and the steering was horrible. The total front toe was almost +6 degrees before I made my adjustments, so be very careful if planning to drive the car prior to alignment.

Anyway, here were the final numbers:
camber
left: - 47' (-.78 degrees)
right: - 53' (-.88 degrees)

caster
left: 7 31' (7.51 degrees)
right: 7 27' (7.45 degrees)

So I gained a around a half a degree of negative camber and an extra ~half degree of caster. The strut pins were not removed. Not only did I get the results I was hoping for, but it seemed to even out my cross-camber readings without needing any adjustments to the strut mounting. I haven't noticed any difference in ride quality, but the car does seem more stable at freeway speeds -- probably from the caster gain. Besides a little more toe-in both front and rear, the car is very close to E90 M3 specifications.

I think the conclusion here is that the M3 control arms (wishbones) are what's responsible for the camber and most of the caster changes on these M3 control arm upgrades. I will probably change the tension struts in the future when my run-flats wear out, but for now I don't want any added stiffness or vibration. For the minimal cost, I think this is a great upgrade.

[lbernielu]

Since you have some M3 front suspension parts, you may want to check out the factory M3 suspension specifications with respect to toe, front and rear. Many experienced track drivers Claim to run 0 front toe and minimum rear. The factory 335 specifications contribute greatly to tire wear, particularly with increased camber, and provide more stability than is necessary. I personally run minimum factory toe front and rear, and am pleased with having more responsive turn-in, without any perceived degradation in straight line stability at normal freeway speeds and more.

[mlifxs]

Thanks for this. Glad to hear about the improvements.

I'm about to install these as well. I pulled my alignment pins a few months ago and pushed camber to -.5, -.6. I'll post my camber numbers after install.

[BMWM.D.]

Originally Posted by lbernielu

Since you have some M3 front suspension parts, you may want to check out the factory M3 suspension specifications with respect to toe, front and rear. Many experienced track drivers Claim to run 0 front toe and minimum rear. The factory 335 specifications contribute greatly to tire wear, particularly with increased camber, and provide more stability than is necessary. I personally run minimum factory toe front and rear, and am pleased with having more responsive turn-in, without any perceived degradation in straight line stability at normal freeway speeds and more.

Thanks, I actually changed the specs for my alignment to an M3 for comparison before I finished. The M3s run 10' of toe both front and rear, compared to 18'/14' on the 335i. So a good amount less toe-in on the front axle.

I probably will change to the M3 toe spec in the future. The only reason I didn't on Friday was that I was short on time and the rear axle was already dialed-in from my prior alignment. You're right, though -- too much toe-in will cause wear on the outside shoulders. I just didn't like how little front camber the car had. With the M3 arms, it's now almost identical to my E46 330ci.

And yeah, I actually run almost zero front toe on my C6 Corvette. I didn't notice any stability issues at all on that car, and tire wear has been great. That car is more of a weekend toy, so I went more aggressive on the alignment.

[mlifxs]

Originally Posted by mlifxs

Thanks for this. Glad to hear about the improvements.

I'm about to install these as well. I pulled my alignment pins a few months ago and pushed camber to -.5, -.6. I'll post my camber numbers after install.

OP I wasn't able to reach your camber level, possibly due to how I instructed the shop (where I have an alignment contract). After I pushed the struts in, had the alignment and told them to make no camber adjustment, just toe.

result was -1.0 left, -1.1 right.

was expecting a little more.

[cvc 22349a]

Originally Posted by mlifxs

OP I wasn't able to reach your camber level, possibly due to how I instructed the shop (where I have an alignment contract). After I pushed the struts in, had the alignment and told them to make no camber adjustment, just toe.

result was -1.0 left, -1.1 right.

was expecting a little more.

That's all I got with M3 lower links, alignment pins pulled and PS springs.

[mlifxs]

Originally Posted by cvc 22349a

That's all I got with M3 lower links, alignment pins pulled and PS springs.

thanks. That kind of suggests to me that the M3 wishbones really only add .5 (?)

I have some Dinan plates ready to go but wondering if the tire wear is worth putting them on....and I just used my yearly "free" alignment on my alignment contract.

[thefull9yards]

Do you need to change out the control arms just to adjust camber? What about toe-in? Sorry, I'm just not too knowledgeable about changing that stuff.

[mlifxs]

M3 wishbones give negative camber but, an alignment is needed after install to adjust massive toe in that also occurs.

[vasillalov]

Weird... With the M3 control arms and tension rods, I was able to get -1.4 degrees Left and -1.5 degrees right of negative camber on the front. I believe the tow was set to 335i specs.

[mlifxs]

Originally Posted by vasillalov

Weird... With the M3 control arms and tension rods, I was able to get -1.4 degrees Left and -1.5 degrees right of negative camber on the front. I believe the tow was set to 335i specs.

yeah, that's what I was hoping for. I may have someone do an alignment check as a second opinion.

Certainly don't regret the upgrade. Handling and steering feel is noticeably improved.

[rikuvalpas]

Hi All,

I'm considering buying the M3 Front Control Arm Upgrade kit for my 2007 BMW 320iA to replace the worn out original parts.

I was checking some American web forums and I could only find references to six cylinder E90 models. Apparently BMW does not sell the smaller 4 cylinder models in the States.

Do you know whether they work also on the 4 cylinder models (2007 320iA specifically)?

[cvc 22349a]

Originally Posted by rikuvalpas

Hi All,

I'm considering buying the M3 Front Control Arm Upgrade kit for my 2007 BMW 320iA to replace the worn out original parts.

I was checking some American web forums and I could only find references to six cylinder E90 models. Apparently BMW does not sell the smaller 4 cylinder models in the States.

Do you know whether they work also on the 4 cylinder models (2007 320iA specifically)?

Yes they will fit. But I would only install them if you are running traditional tires. The bushings/bearings in the m3 control arms will be too hard with runflat tires