545IblupasdU

made this home made ram air with some cold air intake pipe I had from my old car I never used. Car is extremely dirty after a 650 mile drive to Ohio




sealed all the edges with some soft foam padding.....no air can escape through the edges so all the air is forced into the stock airbox!

tightened it up against that diagonal brace you see behind it its very secure you cannot move it unless you put some weight on it!

Flared out the outer edges to grab more air


heres the test video
the drive home was extremely interesting......the first 3/4 tank of gas got me 25.3 mpg. Stopped filled up and the second 3/4 tank got me home with 27.0 mpg on the dot. I had been seeing 28.6 for quite a while but construction and mountains put a stop to that, speed varied from 45-85 mph with cruise control on about 95% of the time. Im very happy with it still testing it out.....I also hit rain, quiet heavy at times, checked the airbox when I had the chance and it was dry! As for power.....above 65 any little touch of the pedal the car would start to pull usually you feel you have to push the pedal and drop a gear but I liked the strong pull of the engine without the drop of the gear.....like I said Im still testing it but to me I feel that its taking much less effort at higher speeds.

heres the car clean with the RPI exhaust an intake I dont think there is a sound difference in the exhaust

BMW fanatic

Very interesting. A lot bigger than the RPI Scoop! The only thing I would do would maybe be paint the pipe flat black or a flat gray. But than again Im 100% anything crome.

545IblupasdU

yes I was planning to paint the pipe flat black....gray could be interesting color choice also.I didnt have the time to paint it though. The RPI scoop is cool but it doesnt channel the air....it just kind of aims it into the opening, I wanted mine to actually force the air into the passage and not have the chance to come back out! Im still using the stock paper filter so there might be room for improvement with the BMC cotton filter!

545IblupasdU

Wow I'm surprised more people aren't interested in this?

SD5Series

very interested in this. you planning on making this for people?

MORI3L

how will this do against the rain?

545IblupasdU

I did it with a piece of pipe that I had laying around.......but if I could find a place that sold the pipe I need for cheap I wouldnt mind making it

545IblupasdU

well I did drive with it on in the rain and I didnt see a problem but its still testing....there is a section at the back of the pipe where water can escape but not sure if it will with high pressure wind is involved!

LessIsMore

Way to DIY, cool project. Would like to see tuning logs with/without of these (or any "ram air" intake for the 5, for the matter). Sounds like you felt a difference, but would be great to make it quantitative.

Flat black and better shaping (no offense, yours is just a function of the repurposed intake pipe) would be needed for me to buy one.

545IblupasdU

This was a boredem thing I just did. I had the idea for a while and just needed time to mess with it....and this was the result of about 3 hours starting from nothing to figuring the shapes to dremel and how to mount! The pipe was just a pipe with the 45 degree bend in it, I dremeled the entrance and exit of each side of the pipe to shape it like that. then used a hammer to widen the entrance i made to grab more air.....and I did it freehand and used a marker to make the shapes to be cut.

This is the original piping, I used the left half!


The thing with testing is how do you simulate 45- 100mph winds into a tube?? Doing that would definitely show true results but putting the car on a dyno and pointing a fan at it wouldnt prove anything. The entrance to the airbox is open and you can snake a wire straight through to the filter area with no restrictions. The 2 things I found difficult were the strange shape of the entrance for the air passage right behind the bumper and trying to seal everything around the pipe to get a true ram air effect without the air escaping, without the seal its like blowing air through a straw half a inch away from a porous piece of material some air may pass through but the rest escapes through the sides. At least mine channels the air where its supposed to go, directly into the passage to the airbox....and it doesnt let air escape back out because of the resistance from the filter. The seal keeps outside pressured air pushing through the filter! Anyway if the concept of ram air is to force the air through the filter, that is exactly what mine does....now I just have to make it pretty lol!

also MORI3L....I was looking again today, I thought there was a little space for water to escape near the back of the pipe but there is not, it is completely sealed....again I did drive in the rain with it and when I checked at the gas station while filling up the filter and filter box were dry.