Geometry questions M3 subframe vs stock

[d k]

Hello

Does anyone know the suspension geometry difference between the stock subframe and the M3 subframe in the rear?

Are the pickup points higher etc....

Also with respect to the front subframe - I dont suspect thats one that you can switch over, correct?
I imagine the engine mounts would be all different.

Many thanks up front!

[atr_hugo]

IIRC, the rear subframe on the 1er and the E9x 3ers is the same. The sub-frame itself is made by the Benteler Group in Eisenach, Thuringia, Germany (don't ask me how I know this ; -).

https://www.benteler-automotive.com/

[fe1rx]

Originally Posted by d k

Hello

Does anyone know the suspension geometry difference between the stock subframe and the M3 subframe in the rear?

Are the pickup points higher etc....

With the exception of the toe link, the rear suspension arms are interchangeable between the M3 and 1-series. The M3 toe link is shorter. This implies that with the exception of that link the pickup points are very similar, but there might be subtle differences.



The basic 3-series uses the same toe link as the 1-series and the same rear subframe, so the shorter toe link geometry is unique to the M3.

https://www.ecstuning.com/b-genuine-...t/33316783713/

[d k]

Originally Posted by fe1rx

With the exception of the toe link, the rear suspension arms are interchangeable between the M3 and 1-series. The M3 toe link is shorter. This implies that with the exception of that link the pickup points are very similar, but there might be subtle differences.

Attachment 1652822

The basic 3-series uses the same toe link as the 1-series and the same rear subframe, so the shorter toe link geometry is unique to the M3.

https://www.ecstuning.com/b-genuine-...t/33316783713/

The shorter toe link alone doesnt provide enough answers to know everything.

For instance, if the A arm mounts are 1/2" higher the toe link might still be interchangeable. Ut it would have a completely different camber curve...

The toe link probably just changes (reduces) the bump steer.
Then again, it couldbe the opposite - they might have thought to add in some bump steer (toe in) during heavy cornering.

It would be real cool to know for sure - need someone with an alignment shop though....