Trip with the BMW Cl

Mostly cosmetic, but most importantly a rework to the OEM exhaust. I am seriously falling in love with this car, even though I know it’s going to be swapped by an N55 powered car the moment I can. Either way, enjoy.

Exhaust

As I have said earlier, this is the first car I have with a decent sounding engine. The classic BMW straight six just sings to redline and I can’t get enough of it. So much so that I had to do something regarding the exhaust. You can buy a myriad of systems for the E90 N52. Active Autowerke, Dinan, Rogue Engineering but the most loved system is the M Performance exhaust which sadly is also the most expensive at close to 1K USD. Now I realize that it costs that much due to the development and the attention to detail, but I was not going to spend anything close to that to get a nice exhaust note or even the $500 that a used one fetches in the forums. My quest began to do an OEM Performance Exhaust mod.

A lot of rumors have been roaming around that the Performance Exhaust is basically a straight pipe with a nice pack of sound deadening material inside an OEM muffler box. I found a reputable exhaust shop and cut open the OEM exhaust to basically take all the excess piping away whilst keeping the sound insulation. As you probably have seen before I straight piped my previous car and whilst I enjoyed it I certainly wouldn’t do it again. I wanted to keep as much of the refinement as I could whilst giving the car the voice it deserved.

After cutting some piping from inside the exhaust I went ahead and kindly asked to have the secondary cats and resonator removed. The resonator removal is already part of the BMW Performance exhaust, so it would be following its design by the book. The secondary cat delete though was to get the added rasp that you can notice in the video, as well as increasing flow without messing with the primary cats or the O2 sensors.

The results were a massive success. I feel like I’m in the perfect balance of outer noise with interior comfort. I roll down the windows and car hear actually pops and crackles as I downshift and a melodious 6 cylinder when caning it. People in the BMW club are raving about it all the time and there have even been a couple pedestrians giving me thumbs up. Total cost? $200 US.

Exterior

The exterior of the car got a much deserved detail and paint correction. It was seriously in need, and now the paint not only looks the part but feels like it too.

Just look at the swirls.
Much better.

Another thing in serious need of reconditioning where the wheels. I am in love with both the tone and the design of the 18s in this car, but the previous owner had them wrecked. A restoration and repaint in the same tone came out at $85 US which I think is the best visual mod to date.

Before
After

I also bought a side marker light since a common issue on E90s is the fogging from the sunlight.

Interior

To my eyes, details make or break a car and the interior needed a whole lot of them. I bought an interior LED kit for close to $35, which is both gave me 0 error codes and a bright OEM like white light. Also there was a starter button from an X1 which cost me $50 and a center air vent without a broken tab for $45. Altogether the changes made this car from a decent looker to pristine in my book.

Hateful, nasty button.
Much Better

Performance

Bought 2 front Kuhmo tires from a member of the BMW club for cheap, had them aligned and balanced. Recently though I have noticed a vibration whilst braking from higher speed which according to the forums and a trusty mechanic is due to suspension arms. This will be the next thing I’ll buy the car for sure and will likely be my last as it is now pretty close to perfection.

Future

There are still a couple details I need to buy to make this showroom fresh.

-Glovebox interior cover (On order, arriving in the next couple of days)

-OBD2 Port plastic cover (On order, arriving in the next couple of days)

-Suspension Components (Arms and Bushings)

-M Performance floor mats

As I evolve with this car I’m falling in love with the brand massively. Repair costs haven’t been outrageous and I have a great community backing me up. When I look at the excel I have of every component I’ve had to change I can’t help but think I’d do it all over again.