More efficient air intake (1.6HDi) - ideas
 

My car's intake is a little messed up. The route that air must go before it gets to the manifold is very long and full of kinks and bends. The air filter is buried deep behind the engine, so by the time intake air hits the turbo it's had more than enough time to warm up - good if you have a gasser and want a WAI, but bad if you have a turbo diesel which prefers cold air.

Here is a diagram of the pre-turbo part:

http://ecomodder.com/forum/attachmen...1&d=1292441405

and picture of how it's all crammed in there:

http://ecomodder.com/forum/attachmen...1&d=1292441405

Fresh air gets scooped up by the intake (1) and goes into a "box" (2) which in many official documents is called an air filter. It has no filter inside, in fact it's not even an air tight box - only one wall (with in and out ducts) and a cover. My guess is that once inside, air must slow down and make a U-turn inside, and that removes debris and water. But when the car is not moving and no air is being forced through the intake (1), then a large protion of the air sucked from box (2) actually comes from inside the engine bay. Next the air goes around the battery to the real air filter (3) way back behind the engine, from which it comes back forward to the turbine (6). From there it passes through the intercooler (7), pressure sensor (8) and finally hits the intake manifold.

So why is the filter behind the engine, while the same car with the larger 2.0 liter turbodiesel has the filter box up front? My guess is that having to take apart half the engine bay just to change the filter will send more customers to the authorized service station... ($$$)

Well, I don't want my air box snuggled back there between the engine block and the EGR pipe, soaking up the heat. Putting an air filter box up front would allow air to take a much shorter and direct route to the turbo, reducing both pumping losses and air temperature. But any new ductwork would have to account for the air flow and temperature sensor (nr 4 on the photo), and maybe for a mysterious pipe connecting the air duct with the header cover (nr 5 in the photo), the purpose of which I have no idea.

Any ideas on what to change? Is redoing the whole intake ducting worth the results?

to answer your question is it worth it. I would say yes.

read the following articles

Part 1
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Part 2(important one on intakes)
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Part 3(maybe not so important for ecomodding)
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Part 4
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Part 5 (The results section has important info)
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dyno with just intake and exhaust mods
http://autospeed.com/cms/gallery/art...0&a=109345&i=7


Would it be possible to fit the 2.0 liter intake system to your engine?

ConnClark, you linked to part 1 twice. The link to part 2 is:
Our Peugeot Diesel - Part 2 - The Intake
I'll have to see. I'd be willing to install anything that will fit and improve flow, but staying with the same make and/or model may reduce the need to improvise weird-shaped parts. I'd like to find a mechanic who has more experience than I do (which means pretty much anyone) and maybe he could suggest something. I'm also waiting for my local Peugeot forum to go back online so I can ask about that mysterious header cover connection.

Could you not draw air directly above the current filter position- maybe from an area similar to the heater vents?

My cabin air vents are located at the bottom corners of the windshield (bottom of A-pillars) and the pressure there seems to be quite low - I get no air inside if I turn the fan off, no matter how fast or slow I'm going - so I'd lose the ram effect. This would negate any gains from reducing the number of bends ahead of the filter box in the present set-up.

(Are the pictures from the first post gone? Can anyone else see them?)

(EDIT: Got it fixed.)

I never could see the pictures in the first post

Doesn't look to me like changing your intake will result in any measurable change. Just because it has turns doesn't mean there is any measurable resistance at your airflow rate...maybe you could gain 1 hp on the top end with an aftermarket intake, but then you'd inhale more dirt.

If you ditch it, let us know if you get any efficiency gains.

The bends are half of my worries. The other is the length of the ducting and it wraps around the engine, warming the air much more than I'd like. Getting rid of all that plastic would also free up some extra room, say for a larger battery, or some other gizmos.

And no worries about aftermarket race filters - I'm not interesed in filters that look like a fishing net - I want to keep the dust and water out.

Have you thought of wrapping the intake in the "thermal reflective" tape?

That is one of the weirdest setups I have seen are there any rubber air pipes if so change then to hard pipes. Plastic and rubber flexes and can cause boost leaks or spikes. a more direct air intake to the turbo and from the turbo to the intercooler and from the intercooler to the engine is a good idea. I'm not sure the hard pipes to the intercooler would work well check ebay for a universal kit that you could cut up and rought yourself this will help greatly. Hard pipes can increase hp as they do not flex. If the intercooler will not accept the piping where it is (it looks like it is on top of the motor. Try and relocate it either to the side or the front of the vehicle this will help lower your air temps. For filters I\'d suggest a AEM dry flow which has been used in desert or off road racing so no dust or water will get in.