[mweisdorfer]

Originally Posted by bmwrip615

Hello everyone so I am about to go crazy and do a lot of modifications to my E90. What would you guys recommend going with the Injen dual cone air intake or the racing dynamics carbon fiber air intake.

Look at AFE

[RSL]

Injen is still open DCI, just with more piping. Not saving anything on density, so might as well skip the extra length, reduce pressure loss and free up pressure ratio going with a shorter DCI route.

As for intake pressure loss and pressure ratio, a sealed intake with scoops at speed may have no more, and potentially less, restriction than DCI, on top of the denser air. Cheap, chintzy items, but scoops do function and a sealed intake can take advantage. It isn't only up to the compressors to pull air through the intake tract, it's being pushed in as well, reducing pressure drop. How much it potentially helps would be very limited or non-existent on the usual dyno setups with portable blowers/shop fans.

On the road, sealed+scoops is consistently faster than DCI on my car with same tune. I've tested quite a few times over the years, but I've never actually tested the pressure in the inlets with/without scoops and that could be an interesting data point. WGDC gives an indication, but is affected by other things and has a tendency not to move as much if you're already running fairly efficiently (larger unstressed turbos, inlets, etc).

If I were in the market for an intake for stock to small/mid hybrids, Momentum GT with scoops and not think twice about it. The ECS intake is about the nicest looking/fitting DCI setup there is, but having an air box doesn't mean it's closed. There are some sizeable gaps around the tubes where they pass through.

Originally Posted by Rob@RBTurbo

If you are referring to the ECS Kohlefaser Luft-Technik Intake CF intakes- they actually have the biggest ID's of any of the others thanks to the thin walled CF material. This is the offering I personally liked the best when I dug into this last year and while considering bang for the buck.

Sadly the AFE Magnum Force setup was a very thick lightweight plastic with very small ID's (significantly smaller than the OE airbox connection ID's), certainly not worth it for those looking to push large power IMO. Anyway perhaps the other AFE's such as the Momentum GT are larger ID'd and if not make up for that flow restriction in cool air. I couldn't get a direct answer on this and didn't feel like purchasing one only for the disappointment that I felt was going to be eminent based on the AFE Magnum Force outcome.

The ECS Tuning Kohlefaser Luft-Technik Intake CF inlet setups are what I'd eventually settled on for my recommendation outside of the standard DCI setups (ie. BMS, CP-E, etc).

Rob

AFE SI: aluminum tube ID is 53.9mm.
ECS CF: both of my tubes are oblong on both ends and have some thickness differences all around.
- Inlet end, tube 1: 53.3 - 56.7mm ID.
- Inlet end, tube 2: 52.8 - 55.3mm ID

My stock air box inlet tube IDs are 55.3mm, give or take 1-2 tenths for minor bends in that thin aluminum. An average of the extremes on the ECS tubes, they're 0-1mm larger ID than AFE SI or about the same ID as the stock box. I never had a Magnum Force/open DCI version in my hands, but assume from your info, that model is noticeably smaller at that connection.