Aluminum Control Arms

#1

I am pretty sure I know the answer, but I just want to verify the M3 front aluminum control arms are NOT legal for spec E30 racing.

#2

You are correct. There’s no reason for everyone to spend more money to all have the same thing. Now, we spend less money…to all have the same thing.

:slight_smile:

#3

Carter wrote:

[quote]You are correct. There’s no reason for everyone to spend more money to all have the same thing. Now, we spend less money…to all have the same thing.

:)[/quote]

From a saftey standpoint, I would highly highly suggest a rules change about this. The E30 325 front control arm ball joints are NOT! heat treated. They have been known to fail prematurely due to their weak properties. The solution is the 95 e36 m3 control arm. Same geometry and weight (hint, no performance gain) but with heat treated ball joints. To cross reference, BMWCCA requires the heat treated ball joint arms to replaced once every two years. Image using non heat treated ones. To prevent rules creap, maybe state the BMW part number to be used.

Barry

#4

Thanks for the tip. We will check into this.

We haven’t had a failure yet but if something is safer, and lasts longer, we’re interested.

Carter

#5

I watched Don Salama plow his E30 M3 into the tire wall outside the downhill at Lime Rock Park many years ago due to a broken ball joint. IIRC, this incident is what started the whole aluminum vs. steel control arm hoopla. "They" claim that anecdotal testing shows that the steel used in the ball joint in the aluminum arms is stronger. What is lacking from the rest of the equation, as far as I know, is any track record of ball joint failures beyond this one incident.

EDIT: THE BMWCCA Club Racing policy regarding steel/aluminum E30 control arms seems to have disappeared from the rules.
http://www.bmwccaclubracing.com/static/2005Series/05start.htm
I always thought their replacement interval policy was a little alarmist but with all the personal injury lawyers around, they have to protect against possible litigation. I would personally like to run E36 M3 steel control arms. They cost less than E30 aluminum ones. Also, since the E36 M3 weighs more and has better brakes, more power, and more tire than an E30 M3, I would think the ball joint would be stronger

Post edited by: edw, at: 2005/08/22 18:44

#6

Meyle E30 arms have all steel ball joints. That’s what I send out to customers. There is alot of cheap junk on the market though.

Just torque them carefully too. Many overtorque and that helps stress them in addition to making them a pain to remove.

#7

I have a 89 i with 122k, it’s build date is 7/88, so I am contemplating replacing the tie rod ends and control arms. I saw a e30 hit the wall at the shen track in june. At hyper fest one of the e36 race cars, the control arm broke, resulting in hitting the wall I believe. correct me if i’m wrong!

I think it might be good insurance to replace these critical parts. After 17 years of exposure to the elements and wear and tear of friction I sure these parts are stressed and more likely to fail.

I’m open to comments, this is just my opionion and welcome any comments pro or con.

#8

I just checked prices and tie rods are $45 each, control arm is $80 each, ball joints are $14 each, so to replace all, parts about $280 bucks. for factory oem parts.

I just dont want to have on of those parts fail while racing!

#9

The need for Al control arms is absolute bunk. The harder joint doesnt really do anything for you, and I’ve yet to see any(?) people snap a CA at the joint. Unless in an acident. The Steel ones are "supposed" to wear out quicker which no one has proven to me.

CA’s Al or steel are a maintanence item and should be replaced after X races (YMMV) or at the end of the season. The Al ones are WAY more expensive to replace. I believe I can replace the steel ones 2-3 times before I reach the cost of the Al and I doubt that I’m going to get that much extended life from a set of Al CA’s

I’ve actually had the Al arms fail on me quicker than the Steel ones on my Ex E30 M3

#10

[color=#0000FF][/color]. Talking to other racers, it sounds as if the OEM tie rods and control arms will work just fine. Sounds like a good idea to replace these if they havnt been

#11

bmwbadboy wrote:

I replace mine at the end of every racing season. This might be overkill but they are cheap and easy to swap.

Carter

#12

Carter wrote:

[quote]bmwbadboy wrote:

I replace mine at the end of every racing season. This might be overkill but they are cheap and easy to swap.

Carter[/quote]

Nah, it’s cheap insurance is what it is. The frequency of replacement is dependant on the number of events you do. Previously, I replaced mine (those were the aluminum versions but I would do the same with steel) every 1.5 seasons. I was running about 5-7 events per season.

For our SpecE30 cars I think we’ll do arms/tie rods each season, perhaps more if we run more events. I’d rather spend a couple hundred to do those parts than find/build a new car!

#13

[quote=“EdW” post=456]
EDIT: THE BMWCCA Club Racing policy regarding steel/aluminum E30 control arms seems to have disappeared from the rules.
http://www.bmwccaclubracing.com/static/2005Series/05start.htm
I always thought their replacement interval policy was a little alarmist but with all the personal injury lawyers around, they have to protect against possible litigation. I would personally like to run E36 M3 steel control arms.[/quote]

BMWCCA CLUB RACING TECH BULLETIN 02-02
E30 & E36 BALL JOINT FAILURE Issue date: 4/02
This is an update to Tech Bulletin 02-97. Similar failures have been reported on E36 vehicles. This bulletin is extended to include E36’s.
Investigation into several Club Racing/Drivers School incidents during the 1997 season have revealed total failure of the Ball Joint Stud on the Lower Control Arm resulting in immediate loss of steering.
We recommend the following preventive measures (until otherwise noted):

  1. When preparing an E30/E36 for club racing, start with new control arms.
  2. Replace all steel control arms after 2 seasons of use or 20 events.
  3. Replace all aluminum control arms after 2 seasons
  4. Replace control arm if a ball joint has any amount of “up and down” play when squeezed with a large “water pump” pliers.
  5. Replace control arm if a ball joint has any “side to side” play in it when grasping the outside of tire and shaking from side to side or up and down.
  6. Do not re-use poly lock nuts
  7. Torque ball joint stud nuts to spec!!
  8. Re-torque nut several times during season. It shouldn’t turn–if it does, investigate why.
  9. If an “incident” involving enough force to bend a road wheel occurs–replace control arm.
  10. When trailering a car, do not tie car down around or thru control arms.
  11. Use quality replacement parts. BMW original or Lemforder brand are the only ones we recommend. There are inferior quality control arms being sold by large, well known suppliers.
  12. It is important to understand that the type of failure we have seen may be undetectable by in car physical inspection. Change the arms at the time and usage specifications listed above, not just with normal ball joint wear inspection.
    Inspect the subframe tapered socket and area around the socket for cracks and elongation–use a mirror to see the upper portion (especially on the right side of car–we have seen many cars that crack in this area). This may cause ball joint failure.
    PART NUMBERS FOR E30 LOWER CONTROL ARMS
    Aluminum 31 12 1 130 823 left $244.00
    31 12 1 130 824 right $244.00
    Steel 31 12 1 127 725 left $115.00
    31 12 1 127 726 right $115.00
    TORQUE SPECIFICATIONS
    Outer–control arm to spring strut with new poly stop nut 47 ft lbs, 65 nm
    Inner–control arm to front axle carrier 61 ft lbs, 85 nm
    To show that “hand or wrench tight” is not appropriate–here are a few more torque specs(notice the big difference in ft lbs)

BMW has a handy pocket sized torque spec book available:
Supplement 13-- part # 01619783691 $12.75
Binder-- part # 01699099704 $ 5.59
Registers divider–part # 01699099705 $ 2.40
Remember that safety is always our first concern. Please take special notice to this bulletin and remember that your car should have a thorough tech inspection before every event. Drive safely and we’ll see you at the track!!!