You've probably not seen an E30 suspension failure like this before

[moatilliatta]

Happens on E36 and E46 also.

I like welding a big washer on the top side also around the inner ball joint boss also.

Sounds like the car could use a better inspection between events.

[Northern]

It's definitely more common for street cars to tear the sway bar tab or engine mount tab off the subframe. Plenty of threads here about those, but I haven't seen this one before.

TBH I thought the reinforcement kits for the inner BJ was just a marketing thing, but I guess not.

[redneckvtek]

Yes, On enduro cars or high-grip cars the ball joint pockets pull out. Took about 2 seasons on my chump-e30s with stock brakes - I would not attribute it to the brakes.

Its probably track-dependent and happens faster if the car takes more curb hits

I never understood the subframe "reinforcement" kits that reinforce the engine mount or sway bar mount areas, as I have not seen those issues before.

[It's Soda Not Pop]

I reinforced my engine mounts and sway bar tabs. I've seen these control arm plates before, but I wasn't sure if that was necessary. At least necessary for what I do with my car. But I might due this mod in the near future for peace of mind.

[Panici]

I will admit I personally have not seen that failure.

However garagistic's reinforced subframes have a plate welded over that area, so it must be a known issue.

https://www.garagistic.com/products/e30-reinforced-front-subframe?_pos=3&_sid=b8f52557b&_ss=r

[kronus]

Passenger side:





Driver side:




Removed:




Car is a lemons racer, 24v swapped with the Nasieg 5-lug kit and e46 M front rotors, 255 tires. ~10 years, 30 endurance races on the subframe. A third of that with the big brakes and tires.

Our spitball diagnosis is repeated heavy braking work hardened the subframe metal and fractured it into pieces.

The final failure was thankfully smooth and uneventful. Driver pulled off the track in a controlled manner after losing steering. No real warning signs before failure except slightly pulling to the left under braking.

Check your subframes!