07 335i coming to life

[Heyfred]

Having intermittent misfire. Plugs and coils are new, so that was out. Tested MOSFETS and they tested good. Car has 82,000 miles on it. From past experience, electronics breakdown over time from usage and heat. After doing some research, replacement MOSFETS are supposedly more durable. Decided to send the DME out and have the MOSFETS replaced even though they tested good. So far, the misfire has not came back. In conclusion, I believe the old MOSFETS were breaking down. The car rips.

 

[Heyfred]

Spent the day getting the car cleaned back up.

 

[Heyfred]

Decided to build my own exhaust system. First time using pie cuts. Used factory mounting hardware and location when possible. 2.5” to 3.5” to VRSF street muffler. Mellow, deep tone. Incorporated a Helmholtz Resonator to tune out a minimal drone a 1600rpm. Absolute joy to drive.

 

[wheela]

Very cool! Curious to hear how you tuned the Helmholtz resonator?

 

[Heyfred]

Very cool! Curious to hear how you tuned the Helmholtz resonator?

Frequency calculator: http://super-null.com/drone.html.
Volume calculator: https://www.calculatorsoup.com/calculators/geometry-solids/cylinder.php

Drone Reduction - Wilhelm Raceworks, LLC

Adding a Helmholtz resonator to my center exit exhaust for done reduction. Calculator to design a Helmholtz to solve your own drone problem.

wilhelmraceworks.com

 

[doublespaces]

And what do you think about the helmholtz, I suspect you don't have a before/after for comparison?

Nice project by the way

 

[Heyfred]

And what do you think about the helmholtz, I suspect you don't have a before/after for comparison?

Nice project by the way

No, but the low rpm interior drone is gone.

 

[Heyfred]

New front splitter installed. Carbon one in post #35 less than 5 minutes. While pulling out of the shop, tapped the curbing at minimal speed, it cracked and split. To the garbage it went. Installed a polycarbonate one that can take a hit and not break. Fit is good. Laser cut out of stainless, made backers that fit inside the bumper cover and one the bottom side of the splitter. Backers are riveted in place, one to the bumper cover and the other to the splitter. Stainless fasteners are used to attach the splitter. Also in the works, full Ohlins, M3 suspension components and various bushing upgrades. The car should be very street/driver friendly and handle like it‘s on rails.

 

[Heyfred]

New tooling made for the bushing install. Bought a second set of rear knuckles so I can build out rear subframe assembly minus the rearend for easy RnR. Getting to being completed. Sending knuckles to get powder coated.

 

[Heyfred]

Upgraded rear suspension is in with M3 conversion with Ohlins and F30 rear brake upgrade.