Age old question of M3 front suspension. Need help with calculation.

[pawa_k2001]

I am in the hunt for more negative camber up front without getting aftermarket suspension nor camber plates. This is my idea, see if you can help me.

My ZHP will be due for a suspension refresh soon so I will be changing most of these components anyways.

From everything I was able to read, in order to install front M3 suspension on a ZHP you need the following. Control arms, spindles, tie rod assemblies and brakes. Front what I can gather, I can reuse the strut and spring setup from ZHP on M3 spindle. This is where I want to gain my camber.

By installing the M3 control arms and spindles, I will widen the track of my ZHP by 18.7mm combined(difference between M3 and ZHP track), so around 9.35mm on each side. This will push the bottom of the wheel out which adds camber. I did some rough measurements and I need help from people that know math formulas.

Strut and wheel assembly is 34" tall, if with "x" measurement you get 0.75 degree negative camber, what would be the camber if you add 9.35mm to "x" measurement? I just need a rough calculation to see if this is worth my time.

[pawa_k2001]

Got an answer from my brother and some friends backed up the answer. If my measurements are right, I will gain another .6-.7 degree of negative camber per wheel. Total negative camber per wheel should be 1.4-1.5 degree after this modification.

Time to dig deeper to see if I can just install the spindles, control arms, brakes and tie rod end assemblies without changing struts. This will definitely give me a better bite on the front axle with a wider track and more negative camber. Should go well with a stock M3 front sway bar. (26mm M3 front sway bar vs 23.5mm ZHP bar)

[sillieidiot]

I don't see why you can't keep the struts/shocks. Pretty much the difference between the M3 and non-m is that the shaft is larger so it requires different top hats. But they both fit fine. I'm technically running M3 coilovers on my non-m. You might need different endlinks though. I would just grab some adjustable ones.

Why are you not going with camber plates? I feel like this would save you a lot more money, and you can adjust it even more.

[slater]

if you're after the wider track, this is great - however, you've already got some wide wheels up front. why not get some ground control street camber/caster plates? they will give you another 20mm of shock travel, too, and work with OEM springs. much less work than sourcing and retrofitting all of the M3 bits (although the swaybar is a good idea, i run an M3 front swaybar on my car - and a non-M 'vert rear bar, which is 20mm).

[pawa_k2001]

I don't see why you can't keep the struts/shocks. Pretty much the difference between the M3 and non-m is that the shaft is larger so it requires different top hats. But they both fit fine. I'm technically running M3 coilovers on my non-m. You might need different endlinks though. I would just grab some adjustable ones.

Why are you not going with camber plates? I feel like this would save you a lot more money, and you can adjust it even more.

I will try go with M3 end links. I just don't need the adjustability of a camber plate, looking for 1.5 degrees of negative camber on a daily driver. I like OEM parts because they have less NVH.

if you're after the wider track, this is great - however, you've already got some wide wheels up front. why not get some ground control street camber/caster plates? they will give you another 20mm of shock travel, too, and work with OEM springs. much less work than sourcing and retrofitting all of the M3 bits (although the swaybar is a good idea, i run an M3 front swaybar on my car - and a non-M 'vert rear bar, which is 20mm).

Camber plates are $400 plus shipping. M3 control arms, sway bar links and tie rod ends cost me nothing extra because they will be installed as a maintenance item when I need a suspension refresh. I have a set of E46 M3 front calipers and new rotors from my M3 after I upgraded to ZCP brakes. The spindles will cost me around $80 for both. I measured my wheels and found that I can fit the 9.35mm track widening on each side, may need 10mm spacers in the rear just to make the car look right.

This is my daily driver(63 miles to work and back every day), I am trying to walk the fine line of modifying it without crossing the invisible line of where I start regretting because the car became to harsh, makes annoying noises, etc. 1.5 degrees of camber, wider track and a front sway bar will make the car more enjoyable when I do my weekend drives while being civil enough and not destroying my tires from daily driving.

[slater]

I will try go with M3 end links. I just don't need the adjustability of a camber plate, looking for 1.5 degrees of negative camber on a daily driver. I like OEM parts because they have less NVH.

agreed. i am lowered a tiny bit on bilstein PSS with new stock upper front mounts, and i am around -1.4º camber up front. same wheels and tires as you (even down to the sizes).

Camber plates are $400 plus shipping. M3 control arms, sway bar links and tie rod ends cost me nothing extra because they will be installed as a maintenance item when I need a suspension refresh. I have a set of E46 M3 front calipers and new rotors from my M3 after I upgraded to ZCP brakes. The spindles will cost me around $80 for both.

LOL. you are just like me... "hmmm, i could just do this and that..." straying from my original goal, justifying upgrades. i still have not learned the KISS principle for cars: Keep It Stock, Stupid.

I measured my wheels and found that I can fit the 9.35mm track widening on each side, may need 10mm spacers in the rear just to make the car look right.

i am at -0.75º camber in the rear, at basically stock height, and with the same wheels and tires as you i didn't rub at all; but with 3mm spacers added (to bring the offsets back in line with stock), i sometimes rub in the rear. in my opinion, 10mm spacers will make the car look ridiculous and you'll also rub like crazy. not worth it for a DD.

This is my daily driver(63 miles to work and back every day), I am trying to walk the fine line of modifying it without crossing the invisible line of where I start regretting because the car became to harsh,

yes, this is the fine line. in my opinion, likely not worth the hassle. i would suggest perhaps upgrading to the M3 front swaybar, and maxing out the camber up front with stock stuff first just to see what you think before going to the extra effort.

[Vas]

Knock out the pins on the upper mounts and you will get a good bit of negative camber in the front.

My wife's zhp is lowered about 1" and with the pins still being there, the camber is at -1.5.

[Sockethead]

I agree with Vas, knock out the pins first and see where you're at... especially if you want to keep things stock/OEM

[sillieidiot]

-1.5 deg isn't much. I'm sure if you decide to lower, it will go pass that. I would punch out the alignment pin, that should do it already. I'm sure after you do everything, you might find out that you may need camber plates anyways to adjust it back. At least that's what I use my camber plates to do.

[Rovert]

Below is my alignment settings after doing my own camber. I knocked the front pin out of the front strut and maxed out both sides. My alignment guy added more toe in that I wanted but said it would help with tire wear because at that toe in angle, the outside which is higher then the inside tire, will scrub evenly.

I have max OEM camber with the rear and my alignment guy adjusted toe in to handle the amount of camber to help with the scrub.

My car rolls and rolls really good. And I've had a 3,000 km road trip and a 1,000km road trip along with daily driving and the tires seem pretty even.

The reason I maxed out rear camber was to keep the weight off the outside of the tires where I had some excessive tread wear from before just to give my rear tires a bit longer life before replacing.



My ride height is: