The Begining

M50 Intake Manifold & BBTB
The M50 intake needs significant amount modification to fit the M52. I purchased a kit from Alpina527 on www.bmwowner.com/forum/. This included the modified M50 manifold and a BBTB (big bore throttle body, this has a wider opening and allows more air through). This is a super kit, very clear instructions and it all fits together really well!

The following picture shows the restriction on M52 manifold. The green line shows the m52 intake size, the blue line shows the size of the m50 manifold.

On the left you can see the M50 intake manifold and on the right the M52 manifold. There is a significant difference!

On the left is the original throttle body and the right is the BBTB.

The next three pictures show the original intake, no intake then new intake.

Install complete…

I had to modify the cover over the injectors to fit the strut bar. With the new intake manifold the cover was too high. It had to be lowered and cut outs for intake tubes enlarged.
All done!