406oc.co.uk

No idea if this actually works or not but i like it better than the factory setup.

The factory intake sits about 30-40mm from the main bumper support below the passengers headlight, i didn't like that... so i did this

Step 1: Remove the lower wheel arch.
Step 2: Remove spotlight (easier to work)
Step 3: Remove intake pipe

You should now be left with something looking like this:



note: We did this a while ago but decided to take photos when i had the bumper off...

We cut the lower wheel arch to form a duct to allow air to flow into a new pipe - we used from flexable pipe like whats on a dryer.



I then bent/moulded/forced/cut my hand the flexable pipe around the intake pipe in the first photo which is from the airbox. Note it's not a perfect seal but surrounds the pipe.





once everything is all bolted back into place it looks like this:



We did spray paint the bottom and the inside of the pipe black to make it look a bit better.

looks a good idea but two things strike me

1 doesnt air flow better in a straight line?with all those bends i think you will lose any benifit[but i could be wrong]

2 dont go through any deep water as it might suck up water like my mates renault did then bye bye engine.

There are less bends in this than the factory setup...

With the pipe not sealed and the vertical pull it would need to do it would be fairly hard to get any reasonable amount of water into the system the pipe to the air box is also corrugated in some places which will stop some water flow and has a couple of holes in it from the factory for water... In saying that i'm not fond of fording rivers in it...

It's also turbo... so through the turbo, through the intercooler, through all the piping, into the intake manifold then into the engine after passing the airfilter...

as long as the water is in the form of a fine mist it shouldn't cause too much of a problem...

Sorry but I wouldn't recommend that mod for anywhere where there's a significant amount of rainfall.

I'm actually hoping for someone to nick the air intake from a 407/C5II as discussed over on the Coupe Club:




Try drowning that!!

wont water get sucked up there a bit to easy ?

I reckon i could drown that Steve

steve_earwig wrote:



Try drowning that!!

but then you all know my ability to turn even a chunky 4x4 into a submarine

Chances are the car will perform a lot worse at speed due to the Venturi Effect causing low pressure under the car, effectively trying to suck the air out of the inlet pipe

There's only one way to see if its gained power, 0-60 times before and after ha

I've been trying to find a good intake position my self.
Been looking at these
http://autospeed.com/cms/A_109300/article.html
http://autospeed.com/cms/A_1023/article.html
http://autospeed.com/cms/A_107824/article.html

Only place i can think of is in the lower grille as i believe its a high boost area (read the 5 articles on high/ low boost)

steve_earwig wrote:Sorry but I wouldn't recommend that mod for anywhere where there's a significant amount of rainfall.

I'm actually hoping for someone to nick the air intake from a 407/C5II as discussed over on the Coupe Club:

Try drowning that!!

Have you seen how much spray you actually get into the front of the car on a wet road let alone in the rain? Try driving with you windscreen wipers off while following someone on a wet road.

My S16 had a front mounted intake like your photo and where the the pipe pointed onto the filter it was forever gunked up with crap from following people and road grim kicked up by cars/trucks when it rained.


we ran an open bottom to the airbox and over 70,000km a lot on gravel roads i never once had a problem with the filter getting water logged or excessively dirty. This did make a difference to the mid-range power, and much improved throttle responce to the car.


The 306 was constantly looking like this:


(we had to knock the dirt out from between the inner plastic wheel arch and the metal wheel arch as it was rubbing against the wheel)

I know it's not ideal and it was just something to play around with, the thought behind the way we have cut the opening is the NACA duct. If you really want to look at improving the airflow you will need to swap out the piping from the bottom of the airbox as it narrows and twists, ideally then into a vortex section of pipe, into a water trap, then ducted through a semi-smooth walled (reduce boundary layer) constant diameter pipe

You can see the 307 intake mounted onto the bumper bar, this leads down to a connecting pipe in roughly the same area as the 406's in my photo above, i'll be looking later to see if something like this is possible.

The intake piping is actually material pipe from the scoop to the pipe connecting it to the airbox.


You guys make it sound like you drive through flooded roads all day, i should be glad then that where i live it's not constantly covered in foot of water...

I have never seen an intake system that has worked significantly better than the standard item. Perhaps on something high powered there are gains to be made, but on our relatively low powered turbo diesels if your gaining a couple of horsepower I'd be surprised, more likely to lose power in most cases.

most of the improvements i've ever found with intake modifications tend to relate to throttle response

a good mod,

But iwouidnt fancy doing that to my car it wouid end up with a Hydrolocked engine,
imho it be a good mod if the car stays away from water