Alfa Romeo Forum banner

Building my own intake

Tags
building
7K views 99 replies 8 participants last post by  MieliPaha 
#1 ·
Evening all,

I am looking at building my own air intake for the 2.4 JTDm that I have. Mostly because I want a gruntier noise and a bit more turbo noise, partly because it would be easier to change a filter mounted in the car, and partly to reduce the 50 bends and corners that the air intake goes through at the moment.

I have a basic idea of what I want to do. I am wondering if anyone can see an issue with the design. I have played around with it already under the bonnet and can't see too much of an issue.

Does anyone have any recommended closed induction filters as well?

I have attached a quick drawing of what I would like to achieve. It's a poor drawing as I rushed it before I was going out haha.

Another thing I will be doing is removing the stupid plastic meshing on both sides of the maf sensor and replacing that with thin honeycomb aluminium stuff like this
 

Attachments

See less See more
1
#3 ·
Finding it hard to find a plant pot style air filter that will fit in the gap at the moment. However a K&N Orion is looking the best option so far and with it being capable of up to 450 or so HP its rated easily high enough for these cars.

As for the honeycomb you can buy it from America. I will find somewhere in England soon enough I am sure. But basically it straightens the flow out so its laminar rather than turbulent going through the MAF sensor.

There is a similar setup already on the MAF's them selves. However being made out of plastic they are much thicker so loads of the actual surface area of the MAF is taken up by the actual plastic mesh which is no good really.

The honey comb being made of metal rather than plastic means it can do the same job if not better but be much less restrictive and take up much less of the area of the intake pipe :)
 
#6 ·
I can see that being a lot more hassle than just using the standard MAf and de-restricting it a bit though :/

I am not aiming for huge increases in power at all really. I am aiming to reduce how much effort the engine has to put in to suck air through during lower revs and also when on boost reduce how much the turbo has to work to draw in the same amount of air (Target set by boost pressure sensor, and air mass measured by MAF sensor)

I think the K&N Orion kit and then a 100mm Silicon 45* bend and I will be able to aim t he 100mm intake directly down into the hole where the stock air box is located. That will give a very cold air intake and also be much less restrictive than the stock design.

I will be going from intake 100mm --> Filter --> Post Filter pipe 76mm --> MAF 80mm (Desrestricted) --> Post MAF plastic pipe 80mm --> Turbo intake pipe --> Turbo.

:)
 
#14 ·
So then,

I decided upon a K&N Orion in the end as most of the ITG filters that I looked at would be way to long to fit in the engine bay. I am hoping this will be short enough and still work properly.
Either way it has a 100mm intake opening so on that I can put a 100mm silicon hose to angle the intake down into the hole where the standard air box is. And then a 76mm outlet that I will have to widen to 80 using a stepped silicone reducer pipe :)

Here is a link to somo information about the filter that I have bought. It is enclosed which is good and is rated up to 500Hp on their website apparently :)
https://www.knfilters.co.uk/news/news.aspx?id=6686
 
#24 ·
Ok mate keen us updated.
Today my friend and I changed the air filter housing out of an old E46 BMW car 330i with the normally aspirated straight six. We had the old housing out in 5 minutes and replaced it with a K&N bolt on air filter. 15 minutes in total! The engine sounds incredible in 15 minutes....
My 2.4 after 45 minutes fitting time with their removal of the under tray and more messing around...it sounds the same as before..???
All I want is hint of the sound of the Audi Quattro's or RS3's in line 5's..,
Our 2.4's only sound like that after 4,000rpm. This is why we need to work on the induction and the exhaust to get that magic....

Sent from my SM-G925F using Tapatalk
 
#30 ·
Sorry to get your hopes up but it isn't done yet. I was just checking the size of the filter in the photo. I need to get 3 peices of silicone hose now.
A straight 76mm-80mm reducer.
A 45 degree 80mm-76mm reducer
Then a 100mm 45 degree intake pipe.
I will then add a bell mouth intake to the end of the 100mm pipe.
I also need to buy a mounting kit of some sort to hold it all securely. And all the jubilee clamps as well :)
 
#32 ·
Been having a look at this now that the air filter, 2 of the silicone hoses, and the bell mouth intake have arrived. It's looking like it's going to be a very snug fit! However I am sure it is still do-able and to a decent standard as well. I will keep you updated. I have just had to order a 45* 76mm hose. hopefully go from the current intake pipe down into the output of the filter housing.

I have attached a quick drawing of how it will hopefully be setup.

On a positive note I am impressed with how well all the silicone hoses fit to what I have now. All nice and snug so the sizes of the internal bore are impressively accurate. Could probably do without jubilee clips if I really needed to they are all perfect snug fits haha.
 

Attachments

#38 ·
Just been looking at mine, not a lot of room is there?
Keeping it as straight at possible is a problem with the area you have and getting a good clear intake.
It's a bit of a head scratcher as to exactly where & how without making it worse?
 
#40 ·
Keeps you out of trouble!
You have to experiment with these things!
I've just been looking at these 'short shifters' - have posted a thread to see if anyone has tried fitting it & if it's actually worth all the hassle?
 
#43 ·
That is a good read that is. What I just can't believe is the design of the current intake setup. This is how it looks on mine (See attached picture)

All be it that the pipe goes up to just behind the front chrome grille but it looks like it shrinks down to almost 45mm diameter :O

So with the huge 100mm intake pipe that I plan on having going down into where the current air box sits and then some sort of cold air feed fitted from the intake and into that general area I am hoping to notice some sort of difference.

I am not even sure what the magnitude of change will be. Probably very little but hey, I really like messing with stuff. Haha
 

Attachments

#46 · (Edited)
I love making improvements too and let's face the 159 2.4 has a 1 out 10 in intake class. If we can make it snort and sound better that's a win right? I also think because of the poor standard set up being too restricted we could see plus 10ps...
Then once you are done all related fault codes can be remapped out with a custom map. So we will have around 260hp with all the mods (swirl flaps, EGR/ DPF delete and over 500nm of torque.
275hp with a full twin 100mm system decat with hollow DPF filter..
I'm all in...?
This is enough for me.
All my other mods are done anyway except exhaust and custom intake....
My Sportwagon already is faster (just about) than my friends 2014 Audi A6 Avant 3.0lt V6 biturbo diesel with around 260hp....
It is matched up to a 300hp Golf R in performance on the Autobahn...
Not bad for a tractor?

Sent from my SM-G925F using Tapatalk
 
#55 ·
*Update*
Bodged it up and started it. Sounds fantastic haha. Got a a right roar.
Deemed that I need a 90* silicone hose 76mm diameter and should fit snug then.

I have removed it and refitted as standard now as I wasn't happy with how it was bodged before.

Having the undertray off has highlighted how much rust there is on the brackets at the front. However the subframe isn't too bad so that's getting done at Autolusso next Saturday along with a full pollybush upgrade and 4 wheel alignment :D
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top