Intake questions

Tyres, exhausts, suspension, strut braces, air filters, brake pads/rotors and anything else for 'dawn raiders'.
Post Reply
dCatch
Joined: Thu 17 Nov, 2016 13:12
Posts: 12

  Z3 roadster 2.2i

Intake questions

Post by dCatch »

Hi all,

I have been reading the fogged air box better intake posts and have since toyed with two ideas. I was wondering whether or not either have been done before and general thoughts.

Current Problem

The current intake of my 2002 2.2 is to the left of the front left headlight and around it. When the bonnet is closed air has to come into the space before the radiator and with apparent difficulty make it into the narrow gap.

Below are two options:

1. Kidney Intake

As there is plenty of airflow via one kidney and the bumper place some kind of scoop just behind the left kidney grill which will direct air into the mouth of the intake better.

2. Foglight mod

As front fog lights are not legally required in the UK replace this with an intake.

This would involve disassembling the fog light to make it into an air scoop. Then run a large diameter pipe into the bottom of the airbox. As the fogged airbox post this would be large diameter to stop water being actively sucked into the airbox and have a rodent mesh to stop things getting into the airbox.

Thoughts?
therealdb1
Joined: Tue 25 Jun, 2013 21:47
Posts: 263

  Z3 roadster 2.0

Re: Intake questions

Post by therealdb1 »

You are confusing air velocity with air volume or, more importantly, the mass of oxygen you get into the engine since the rest of the air is superflous.
I shall not go into the physics, but if you scoop the air in at high velocity the pressure will drop and therefore so shall the density and ultimately the mass of oxygen available. The opposite of what you want.
This is why your car has been designed with the intake behind the headlight so that air is sucked in by the induction from the engine not pushed in by the flow of driving through the air.
If you want to improve things you need a larger diameter intake collecting air that is as cool as possible and as still as possible. Take a look at some of the proprietry induction kits and then you'll have an idea of what you are trying to achieve.
Before anyone asks, turbos and superchargers still draw air in from a still place but they compress the air increasing its density and therefore the mass of oxygen going into the engine it is not simply a case of pushing the air in quicker.
dCatch
Joined: Thu 17 Nov, 2016 13:12
Posts: 12

  Z3 roadster 2.2i

Re: Intake questions

Post by dCatch »

Apologies if I worded the original post badly, but no, I am not confusing or confused by the difference between the air pressure and the velocity.

In both these situations I would be keeping the original airbox, not replacing it with a direct scoop into the intake.

These solutions are to try and provide more air to the airbox.
User avatar
pingu
Joined: Fri 30 Apr, 2004 16:01
Posts: 3412

  M roadster S50

Re: Intake questions

Post by pingu »

Look at the M setup on realoem (or elsewhere). It has the fogged airbox as standard. There is no anti-rodent mesh - and you do have to be aware that you can't drive through floods :shock: .
Pingu
dCatch
Joined: Thu 17 Nov, 2016 13:12
Posts: 12

  Z3 roadster 2.2i

Re: Intake questions

Post by dCatch »

Thanks for the tip. I have found realoem to be really useful.

Don't worry I don't make a habit for driving underwater!

So on realoem I found this page:

http://www.realoem.com/bmw/enUS/showpar ... Id=13_0934

This is quoted as being the Z3M model but this is exactly the same as mine is already. Is this what you are referring to or are you talking about a different style?
User avatar
pingu
Joined: Fri 30 Apr, 2004 16:01
Posts: 3412

  M roadster S50

Re: Intake questions

Post by pingu »

Image

The one above is the realoem for my car, but it is wrong.

11 is actually a hose that goes from the bottom of the filter to the brake duct (Item #7 below)...

Image

The brake duct fits in the hole where your foglight is...

Image

Sorry for the poor explanation, but realoem is really poor in this area.
Pingu
dCatch
Joined: Thu 17 Nov, 2016 13:12
Posts: 12

  Z3 roadster 2.2i

Re: Intake questions

Post by dCatch »

Ahhh okay. So is that set-up (basically what I suggested in my second option) what the Z3M comes with stock?

At the moment the airbox is fed via item number 1 on the second diagram you posted. Which sits behind and around the headlight.

Thanks for the helpful explanation! At some point I will wrangle the fog light and bumper off to see if there is space for my scheme.

I have seen a number of posts on other forums where people do a similar thing with E36s.
User avatar
pingu
Joined: Fri 30 Apr, 2004 16:01
Posts: 3412

  M roadster S50

Re: Intake questions

Post by pingu »

dCatch wrote:Ahhh okay. So is that set-up (basically what I suggested in my second option) what the Z3M comes with stock?
Yes :)
Pingu
bertiejaffa
Joined: Fri 26 Jul, 2013 09:28
Posts: 1733

  M roadster S50
Location: Manchester

Re: Intake questions

Post by bertiejaffa »

It works well on the M as that space down there also provides additional air flow to cool the brakes.

I need to do something on mine - with having the bodykit on the OEM scoop from the bottom of the bumper isnt there so mine just sucks up air from the bottom of the air filter which is not ideal (wasn't me that did it) but ultimately I need to make something that replicates the M solution
Here come the girls.....
Image
My //M Refurb
My First Zed Journal
Post Reply