[f32christian]

im doing base to msport front bumper conversion on my 2015 bmw 428i i know all the holes for the pdc are the same but i just need to know what size the holes are the body shop already has the bumper just need the size before they drill it and paint it.

[visionaut]

Useful info here. Hole size may be pre-LCI vs LCI dependent…

[Oksamit78]

Hey. Hope it is not too late with the response...
You are slightly incorrect for M Sport... all 4 pdc sensors ARE the same, but the inner 2 holes are larger than the 2 outer holes. The larger holes require to use different PDC mounting brackets, some people call them shrouds. The reason is to redirect the conical beam of the two center PDCs slightly up (above horizontal plane) because these PDCs are closer to the ground in the center and the local curvature of the bumper cover would force them to point down. Otherwise they will be constantly triggered by the ground. It is the same thing for F30 M Sport cars as well.

The PDC holes are the same only on non M Sport bumper covers, like on your pics.

Here is the picture of PDCs properly installed in M Sport F32/33/36 front bumper:


OEM sells the mounting kit, just get the one for M Sport Bumper. Once you have the kit, you can measure the mounting brackets for inners.

Found the kit number: 51118065982

Look on this image at the the two black "mushroom" looking brackets in the middle of the group. You will notice a larger diameter protrusion on the their tops - these are the holders of the center PDCs. There is a left one and there is a right one. If you install them backwards - PDCs will be pointing at the ground. Also, these two should be painted when your new bumper gets painted in order to match color. Paint them BEFORE install into the bumper cover. All brackets are installed using a double sided tape, the tape is already on the brackets if you purchase the OEM kit.


Here is the better picture of the brackets:


The outers - the hole diameter is a hair smaller than the diameter of the silicon seal ring that is installed on the PDCs.

One last thing - all holes' diameters are in mm and not in fractions of an inch. Based on previous post, I believe the outers are 18 mm diameter, and the inners are 33 mm.

[f32christian]

Oksamit78
ok so i already got the holes drilled and the bumper paint matched. just waiting on grilles to install it. but if i were to transfer all the pdc sensors from my base bumper to the new msport one (on the base bumper there all the same size) they should fit fine because i drilled 18 mm holes?


edit: okay now i see what your saying, i can see how that might be a problem, worst casenerio i will have to buy the new sensors and drill a bigger hole and pray i dont crack the paint. thanks for your response!

[Oksamit78]

Yes, the holes should be 18mm - universal. See the pic of one of the sensors I have with the silicon seal ring measured.

You won't need to purchase different sensors in the worst case - sensors stay the same. You will need to purchase mounting kit that includes two mounts with larger protrusion and to enlarge the two center holes to a larger diameter hole. Those mounts are designed to redirect the sensor to point slightly up. Regular 18 mm sensor with silicon ring fits into that holder/bracket. Example shown on my other picture-leftover of the kit for my F34 GT.

As for drilling and praying not to crack... I've done pdc retrofits on already painted BMW bumper covers (e90, F30, F34) using this type of tool:
https://www.amazon.com/High-Speed-Le...s%2C119&sr=8-5
Works like a charm. Just get the one that has a matching diameter step.

[f32christian]

got the bumper installed, how does it look?

[_ObiJon]

Originally Posted by f32christian

got the bumper installed, how does it look?

Turned out great. Fitment looks good, too. Are side skirts next?

[f32christian]

yes either side skirts or rear bumper so i can change the diffuser and do a dual axle back exhaust.

[Oksamit78]

Originally Posted by f32christian

got the bumper installed, how does it look?

Looks really good.

All 4 sensors working as intended without "false-positive" triggers of the middle pair?