[OllieF31]

Hello

I have a 2017 F31 which is absolutely fine, I recently purchased an aftermarket m performance kit, I installed the front splitter, and in the the centre support used bolts and washers, the thing is on absolutely solid, however since installation at around 65mph onwards I get a vibration which feels like a wind vibration which gets worse the faster I go. If I am behind another car it does not do it. Is this common for the aftermarket splitters? I have checked all under trays etc and all fine, the splitter i purchased is one that doesn’t have a central support bar, I have seen some that have these and some that don’t. Before I purchase another one has anyone else had this?

Thanks in advance

[MY340i]

It’s usually the centre that bows and rips off. Do you have pics of your install?

[OllieF31]

I can get some pics tomorrow of the install. It’s on rock solid, the centre is bolted up and I have a plate the other side with lock nuts so it doesn’t budge, but only way I can describe it is as though it’s a flapping vibration noise and feel in the car, lots of people seem to have the splitters but no matter of searching not found someone having same issue. Could be the one I have is just crap

[YODI]

Is your splitter the style that's in half and joins in the middle?

[OllieF31]

No the main lower lip part is one bit, and the canard bits under the fog lights bolted onto that.

[visionaut]

Both top and bottom of your splitter are smooth? Is the bottom inverted wing shape completely boxed in (no loose edges). I’ve seen some ‘raw’ underneath (so bad aero, poor structural strength).

And I’ve seen quite a few reports of cheap imitation splitters breaking at speed.. Sometimes ya gets what ya pays for.

[OllieF31]

Ok, so mine is smooth on the top, but underdeath is like you say “raw”. Like a formed piece of plastic, so this could be the issue? I have seen ones that are smooth too and bottom and are formed in one piece and have a support piece that fits in between, are they better?

[visionaut]

Definitely.

(Suggest you review the authentic MP splitter design details, incl installation instructions — then go shop for one as similar as possible and install it the way the MP splitter is attached.)

[OllieF31]

Thank you, I will do that. Cheers

[TurboWeasel]

That and clouting it on the floor every time I went into my local sainsburys and multistorey car parks were why I removed the splitter off mine.

Who ever fitted it to my car originally used wood screws, which rusted nicely and had to be cut off with a dremel. Good work Oh and the corner trims eroded the paint away underneath from all the wind pressure and trapped grit. Nice.

Don't do it Or use the genuine BMW kit if you really must.