Played around with the with configuring an inlet system. There might be some subtle changes but I am pretty confident the setup I sketched out will work.

The OEM system seems to perform well for what it is, the goal with this system is to achieve similar filtration and low intake temps while shortening the intake systems length. There are some high HP 335ds which essentially run an ultra short; filter - MAF - turbo inlet pipe. The benefits of the short run and high flow seem to outweigh disadvantage of having the filter in the engine bay and sucking hot air. I hope to have a system that is as short as possible while introducing cold air. Turbo noises and having a unique inlet which cleans up the engine bay are bonuses.

The key to the system will be a 3.5" 90 degree oval pipe made by CXRacing. This X5M intake was the closest thing I found to what I want to achieve.


Here is a scribble of the system. It's worth noting the OEM air filter is a larger 9.5x12" panel filter and looking that size up on K&N's website it should flow ~600cfm, that's K&N's panel filter and is thinner than the Bosch unit BMW uses so I assume the stock filter flows a bit less, maybe 500-550cfm.

K&N offers two filters that will work, the RC-5000 which flows 600cfm and the RC-5040 which flows 1,000cfm. I might see if I can atuff the 5040 but if it's too much hassle then the its nice to know the 5000 essentially flows the same as stock.


Conveniently the OEM turbo inlet pipe houses the PCV connection


With the upper portion of the pipe being removable there is a nice flange to clamp onto


Here is the everything but the turbo inlet pipe installed


The next 2 photos show the MAF mocked up and spaced as if there was a 3" to 2.5" reducer between it and the turbo inlet pipe. Off the MAF will be a 3.5"-3" reducing 90 degree silicone elbow directly connected to a 45 degree elbow which connects to the oval pipe. The goal is to have the oval pipe inline with the vehicle and have the silicone do the bending but if space is limited then I might skip the 45 bend and run the pipe direclty off the 90 degree elbow, we shall see.



When reinstalling the turbo inlet pipe the PCV pipe split, you can see it was cracked in multiple locations. I had some heater hose lying around which fit well.



I am excited to delete this leaking CCV system in favor for a vented oil catch can.


Upgraded the switch for my QTP exhaust valve, not sure if I will end up using a wireless controlled but if I do a hardwired switch this toggle is much easier to operate and offers a cleaner design.


Did a few 0-60 runs, 6.5 was the best but it was also on a slightly uphill road so I expect a 6.3 could have been achieved. Not very exciting but nice to have some sort of baseline before power increases. Currently running JBD @10 and a trans tune.


Speaking of trans tune I was having some delay in acceleration from a standstill, part of it seems to be electronic off the pedal but there is also an elastic like delay which I assume is related to the torque converter. Rod's trans tune does manipulate the TC so I asked him about it and he sent and updated file V12.3 to HP5 IIRC.



In the continued spirit of preventative maintenance I replaced the fuel filter.

Turns out the one installed was dated 2014... overdue!


New filter installed, notice 2019 date.


I also noticed some water ingress via the cowls and I am aware the injector related issues this can cause and although I live in San Diego where precipitation isn't so common, I still wanted to nip it in the butt.



Central cowl piece removed, notice the ends where the oem foam has been smashed and morphed into a goo.


I cleaned off the edges and installed some OCI butyl. I do a lot of headlight work so I conveniently had this laying around. I laid a thick bead at each end.



With the panel reinstalled you can see the excess squishing out. This is what I wanted to make sure there were no gaps but its a bit of an eye sore and butyl can be a mess especially when warm so I trimmed it with a razor and gave it a leak test. Good to go!



My "engine acoustics" were chewed up from a rat at some point and contaminated with carbon via boost leaks so I trimmed up the eye sore a bit and I decided not to install the OEM engine cover, because of this I also removed the oil filler neck extension. I like to tidy up the engine bay as I go and keep things minimal as it makes it easier to wrench.