3 dr cars have a much better bracing between mid ships to fwd rear subframe connections. Installed the hardware below this week on my 5dr.
1 x 33326797099
6 x 33326764505 (or 07119907189 longer bolts if using m3/4 spacer, part no. 33312284647)
1 x 33326793651
1 x 33326793652
2 x 33306793892
2 x 33326796225
2 x 33306861221
I didn't get any photos - here's an extract from an F30post showing key extra F32 parts being swapped out on f30. Similar to what I did on my F20.
http://f30.bimmerpost.com/forums/sho...78&postcount=7
Components to be installed
F30 underside - f20 very similar and brace plate across transmission tunnel will be removed
As will these parts be removed
And replaced with these on both sides
How it will look when I'm done
Also I will re-use the f8x alloy cross bar de Item # 2 in the attached realoem page. Part no. 33312284647 and the longer bolts as a spacer / stiffener.
http://www.realoem.com/bmw/showparts...81&hg=51&fg=80
Best way to describe impact is its like having upgraded bushings in the rear subframe and rear suspension arms.
Much less flex when putting the power down on straight or out of a corner. Car feels more stable and less squirmy. Especially as I'm running Jb4 stg2 with ~ 400/460 crank power and torque c/w LSD.
On my regular commute this morning, there's a roundabout with my exit having a tight left immediately after the exit. Road was wet due to rain and 2 different road surfaces - grippy on the r'bout and shiny on the road with the tight left at the exit.
Normally, with a firm squeeze on the throttle, I get a tad of "hip wriggle" as the car's rear axle makes the transition from grippy to shiny surface. That's gone now with F21 underbrace and M3 x brace spacer.
BP