[W37V]

Originally Posted by mweisdorfer

The M3 control arms have a natural camber of .5. You should print off the literature from the net and let the alignment shop know that.

The only real benefit from the M3 arms in the rear is in cornering. Your tires will wear evenly, if you like to drive the car hard on "S" turns for example.

Otherwise, only your front tires will wear evenly at this point.

The rear m3 arms are solid aluminum vs folded steel and the bushing in the arms are engineered stiffer with a better design.

If you have a Bentley Repair Manual, it does have the factory specs of the car, which in fact does toe the tires inward.

I would print that off too and let the alignment shop know what the factory specs are. Therefore, the tech can take all of the information you have given him and align the car appropriately based on the upgraded equipment and factory specs

I don't have Bentley repair manual.

I will try to find information on front m3 control arms for alignment shop.

[Fundguy1]

Originally Posted by W37V

I don't have Bentley repair manual.

I will try to find information on front m3 control arms for alignment shop.

Tell them to use the m3 specs for alignment. All i do.

[W37V]

Originally Posted by mweisdorfer

The M3 control arms have a natural camber of .5. You should print off the literature from the net and let the alignment shop know that.

The only real benefit from the M3 arms in the rear is in cornering. Your tires will wear evenly, if you like to drive the car hard on "S" turns for example.

Otherwise, only your front tires will wear evenly at this point.

The rear m3 arms are solid aluminum vs folded steel and the bushing in the arms are engineered stiffer with a better design.

If you have a Bentley Repair Manual, it does have the factory specs of the car, which in fact does toe the tires inward.

I would print that off too and let the alignment shop know what the factory specs are. Therefore, the tech can take all of the information you have given him and align the car appropriately based on the upgraded equipment and factory specs

I don't have Bentley repair manual.

I will try to find information on front m3 control arms for alignment shop. In several threads, some people mentioned that rear M3 arms are the same as regular 3 series and that other than providing better bushings, no other gains are to be had.

Is there a difference between upper and lower rear control arms (m3 vs regular)? Just to clarify further, are uppers same as regular 3? Are lowers same as regular 3?

[mweisdorfer]

Originally Posted by W37V

I don't have Bentley repair manual.

I will try to find information on front m3 control arms for alignment shop. In several threads, some people mentioned that rear M3 arms are the same as regular 3 series and that other than providing better bushings, no other gains are to be had.

Is there a difference between upper and lower rear control arms (m3 vs regular)? Just to clarify further, are uppers same as regular 3? Are lowers same as regular 3?

The rear M3 arms go on the upper portion of the wishbone suspension and do camber the tires in naturally to .5 like do on the front. They are made of solid aluminum vs folded steel. The lower control arms are not an option for the M3 arms. You can go after mkt for lower arms if you want. I know for example you can get a rear lower toe arm. If your looking to make the lower control arms better than stock, I'd change out the bushings to white line. Yes, there's better than white line, but power flex is not very cost efficient.

[W37V]

Originally Posted by mweisdorfer

The rear M3 arms go on the upper portion of the wishbone suspension and do camber the tires in naturally to .5 like do on the front. They are made of solid aluminum vs folded steel. The lower control arms are not an option for the M3 arms. You can go after mkt for lower arms if you want. I know for example you can get a rear lower toe arm. If your looking to make the lower control arms better than stock, I'd change out the bushings to white line. Yes, there's better than white line, but power flex is not very cost efficient.

So, should I get this entire kit?
https://www.fcpeuro.com/products/bmw...-e93-bmwmcaktr

nah

[justpete]

Originally Posted by W37V

I don't have Bentley repair manual.

I will try to find information on front m3 control arms for alignment shop. In several threads, some people mentioned that rear M3 arms are the same as regular 3 series and that other than providing better bushings, no other gains are to be had.

Is there a difference between upper and lower rear control arms (m3 vs regular)? Just to clarify further, are uppers same as regular 3? Are lowers same as regular 3?

Use M3 camber spec with zero toe for alignment, that'll work fine.

Rear M3 arms are _identical_ to stock arms with the exception of the way they're made. Same length, same bushings, same spherical bearing. They have _zero_ effect on handling, don't waste your money.

The M3 lower camber arm (spring arm) retrofits cleanly with the exception that the shocks will need to be changed to accommodate the different lower mount design. Helps a bit with handling but afaic not worth the effort without replacing the inboard bushings with welded-in spherical bearings.

[W37V]

Originally Posted by justpete

Use M3 camber spec with zero toe for alignment, that'll work fine.

Rear M3 arms are _identical_ to stock arms with the exception of the way they're made. Same length, same bushings, same spherical bearing. They have _zero_ effect on handling, don't waste your money.

The M3 lower camber arm (spring arm) retrofits cleanly with the exception that the shocks will need to be changed to accommodate the different lower mount design. Helps a bit with handling but afaic not worth the effort without replacing the inboard bushings with welded-in spherical bearings.

That is very detailed answer. Thank you!

I will not mess with the rear end (maybe get different diff but that is all).

[Fundguy1]

Originally Posted by W37V

That is very detailed answer. Thank you!

I will not mess with the rear end (maybe get different diff but that is all).

Rear subframe bushings recommended and i need and you may need to rear camber arms. With my lowering and monster tires i need to adjust the camber slightly more than oem allows. Wait till alignment to find out if you need.

[W37V]

Originally Posted by Fundguy1

Rear subframe bushings recommended and i need and you may need to rear camber arms. With my lowering and monster tires i need to adjust the camber slightly more than oem allows. Wait till alignment to find out if you need.

bushings are def on the list. I think I might do M3 set instead of powerflex. However, I will cross that bridge when i get to it.

[Fundguy1]

Originally Posted by W37V

bushings are def on the list. I think I might do M3 set instead of powerflex. However, I will cross that bridge when i get to it.

I used stiffer than m3 and no regrets. The stiffness of m3 is v65. There's v75, v95, and solid. I used AKG v95 black so there was some but minimal give. Works great.

[HP Autosport]

Originally Posted by W37V

bushings are def on the list. I think I might do M3 set instead of powerflex. However, I will cross that bridge when i get to it.

M3 will likely last a long time. Some of the poly may get harder over time and eventually crack.

[mweisdorfer]

Originally Posted by W37V

So, should I get this entire kit?
https://www.fcpeuro.com/products/bmw...-e93-bmwmcaktr

That is the kit for the rear that I have. I am happy with it.

[mweisdorfer]

Originally Posted by justpete

Use M3 camber spec with zero toe for alignment, that'll work fine.

Rear M3 arms are _identical_ to stock arms with the exception of the way they're made. Same length, same bushings, same spherical bearing. They have _zero_ effect on handling, don't waste your money.

The M3 lower camber arm (spring arm) retrofits cleanly with the exception that the shocks will need to be changed to accommodate the different lower mount design. Helps a bit with handling but afaic not worth the effort without replacing the inboard bushings with welded-in spherical bearings.

No. The rear m3 arms DO NOT HAVE THE same bushings. They are also not the same arms as OEM. The OEM arms arm straight and made of folded steel. The M3 arms are made of aluminum and have a curve to them.

[Fundguy1]

He meant type of bushing, rubber vs spherical. And I think from a geometry standpoint the same, not construction.

[justpete]

Originally Posted by mweisdorfer

No. The rear m3 arms DO NOT HAVE THE same bushings. They are also not the same arms as OEM. The OEM arms arm straight and made of folded steel. The M3 arms are made of aluminum and have a curve to them.

Sorry, but you're wrong. The M3 and non-M3 arms use _exactly_ the same rubber bushing and spherical bearing. They have different failure mechanisms related to their differing construction and design but unless you're running an M3 the difference is of absolutely no concern and has absolutely _zero_ affect on handling. Nobody said they were the same design, simply that they have the same bushings and bearings.

Read this: http://www.1addicts.com/forums/showthread.php?t=1079383

[justpete]

Originally Posted by mweisdorfer

No. The rear m3 arms DO NOT HAVE THE same bushings. They are also not the same arms as OEM. The OEM arms arm straight and made of folded steel. The M3 arms are made of aluminum and have a curve to them.

I should also mention I've used the M3 upper arms for about 20K miles and then switched to BimmerWorld adjustable arms with Aurora Performance Race ballends and the difference is obvious and an extreme improvement. The M3 arms just weren't ever right, definitely didn't help handling at all.

[mweisdorfer]

Originally Posted by justpete

I should also mention I've used the M3 upper arms for about 20K miles and then switched to BimmerWorld adjustable arms with Aurora Performance Race ballends and the difference is obvious and an extreme improvement. The M3 arms just weren't ever right, definitely didn't help handling at all.

Ok that's on a 135 not a 335. The OEM part numbers for a rear upper guide rod are almost identical but one number for the 135 vs 335.

Do you have a study with results for a 335 with OEM arms vs M3 arms in the rear.

I just installed rear m3 control arms 2 months ago and the bushings in the m3 arms are not the same vs the bushings in the OEM arms.

[justpete]

Originally Posted by mweisdorfer

Ok that's on a 135 not a 335. The OEM part numbers for a rear upper guide rod are almost identical but one number for the 135 vs 335.

Do you have a study with results for a 335 with OEM arms vs M3 arms in the rear.

I just installed rear m3 control arms 2 months ago and the bushings in the m3 arms are not the same vs the bushings in the OEM arms.

Did you measure the spring rate of the bushings? I think you'll find they're identical regardless of appearance.

[edit]
The main point here is that the M3 arms offer absolutely no improvement in handling at all. If you've driven a car that can handle the difference is readily apparent.
[/edit]

[W37V]

Originally Posted by justpete

Sorry, but you're wrong. The M3 and non-M3 arms use _exactly_ the same rubber bushing and spherical bearing. They have different failure mechanisms related to their differing construction and design but unless you're running an M3 the difference is of absolutely no concern and has absolutely _zero_ affect on handling. Nobody said they were the same design, simply that they have the same bushings and bearings.

Read this: http://www.1addicts.com/forums/showthread.php?t=1079383

Wow that guy really went all scientific about it.

[JETmn]

Do you need to do anything besides the 4 sub frame bushings? Any improvement from doing diff bushings or anything else while I am in there? My car is DD so I want to keep it very streetable. I am looking at whiteline bushings. I have had them on other cars in the past and they were very good.

[Fundguy1]

Maybe rogue engineering transmission bushings. Rest not so much.