air filter box for 3.5L conversion

[rsporsche]

okay guys -

my car has a 3.5 injected conversion, but has one of those k+n type air intake systems. would love to get rid of it and go to something that looks more natural under the hood. from looking at pictures, it looks like many people have used the piece from e24 (6 series) or e28 / late e12 (5 series).

i have 2 questions,
1. for those that have this on their car, how did you mount it to the car? my memory tells me that on the e28 there was a bracket that you bolted the housing to. it also seems that there was a bracket on top of the valve cover for the inner mount.

2. anybody got one for sale, in good condition for a reasonable price?

thanks
scott

 

[Ed G]

Would 3.0CSi filter assy work?

 

[BonitaCS]

I picked one up from the junk yard for next to nothing. It rests on top of the valve cover on two rubber bumpers. I had to cut off the bracket that attaches it to the fender and fabricate a new one to fit correctly. I'm running Motronic 1.3 with 320 runners and a L jet log.

 

[rsporsche]

Would 3.0CSi filter assy work?

i'm not sure that it would, as the distance from the end of the manifold to the opposite end of the afm on the newer injection systems is too long compared to the distance from the manifold to the edge of the CSi airbox. this is a guess on my part from looking at the pix.

 

[rsporsche]

I picked one up from the junk yard for next to nothing. It rests on top of the valve cover on two rubber bumpers. I had to cut off the bracket that attaches it to the fender and fabricate a new one to fit correctly. I'm running Motronic 1.3 with 320 runners and a L jet log.

on the 535i / 635csi, there was a bracket on top of the valve cover that the airbox fastened to - i guess you are just using bumpers instead. i would appreciate it if you could take + post a few pics of the bracket that you fabricated ... as i think that is something i am going to have to do to get rid of the noisy air intake.

 

[sfdon]

Lots of ways to do it- from a single drilled hole and rubber mount to a custom bracket

 

[rsporsche]

thanks Don, will give it a go.

 

[johanaxelson]

I actually modified my original one to fit. Had to make it a bit more shallow and move the intake a bit. (sorry, no picture here, can post when I get home)

But as I will add a Megasquirt now I will get rid of the whole AFM part which opens for more possibilities.

As a side note I had my car on a dyno a few years back and they ran it with and without airfilter and said the airfilter cost about 5 HP at max rev. Surprised me a bit as I thought the difference would be bigger.

 

[BonitaCS]

Here is what I did, sorry for the poor photo quality... You can see a rub mark on the top of the air box, that was from the first bracket where it rubbed the under side of the hood so be careful of the clearance here. I used a metric rubber vibration isolator from MMaster-Carr to mount the bracket to the fender. Also need to be careful your bracket clears the fender. Good luck.

Scott