Aerodynamically optimising engine intakes

Optimising intake systems using aerodynamic techniques

[@directionwood]

this is one of those classes that you dont sign up for that you learn the most from. I have learned so much so far from you Mr. Edgar. Its a pleasure that you can share what you know with anyone with an internet connection and the desire to search for this type of stuff

[@makantahi3731]

how could you learn anything without his book

[@hectorae86]

It has been quite a while since I subscribed to any channel, but I just did. Good work man, good work indeed

[@KarriKoivusalo]

Volvo 940 Turbo is a puzzling case of the intake box restriction. Originally in 740 there was an automatic system for cold and hot air intake by moving a thermal actuated flap between hot and cool air channels. The system had been eliminated in 940 turbo, there channels were left blank (clocked), there was just a tiny hole (about 30mm or so) drilled on the side of the box with a bellmouth, drawing air from a less hot zone in the engine bay. However, the original cool air intake bellmouth (~65mm in diameter) was still included and it was an assembled, not a molded part; someone at the factory had the job of trimming and fitting a bellmouth piece to a non-functional blind airbox hole! Anyway, I think it's within reason to assume making the original channel operational again made some improvements.

[@Jason-fp7vi]

Hello Julian, I was inspired by your video and your air modifications book. Magnehelic gauges are expensive in Canada because of shipping, so I looked for another solution. I know a tiny bit of programming, so I managed to connect a Chevrolet cavalier 1 bar MAP sensor to an Arduino, and read the 0-5 volt signal as a pressure in kpa/psi. The map sensor cost me $10, the Arduino I already had but is about $15 used. Granted this reads absolute pressure, not a differential. I will have to take a baseline atmospheric reading, and then subtract the reading within my intake to get the difference. Thanks kindly for your videos and the books, I would have never thought to pressure test intake restrictions

[@JulianEdgar]

Sounds good.

[@maxspruit8370]

Maybe after improving the exterior earo i will tackle this. Then i can compensate for the mpg gains with some wide open throttle. Awesome video.

[@simonbertioli4696]

Good day Julian. I have been looking at your video....with interest... However, l may need a spot of guidance.. If l need to purchase an oscilloscope would a program download to the laptop do..of which there are many.. Or would it be better to purchase an actual one.. Hanmatek DOS1102 ... For example. Also the differential air measuring... Magnahelic 0-5pa Or higher reading.. I have 2 cars that need testing. 1 being 1.6 petrol 2006 all electronic Opel. The other a 1997, 1.9 sdi VW diesel non turbo...with an EGR valve with just 2 wires. Nothing special.. Any ideas... Thanks.. Will look out for your books too

[@91rss]

would there not be an issue if an AFM /MAF is calibrated for a certain speed /mass of air, now seeing more and not responding correctly?

[@JulianEdgar]

Both an airflow meter and a MAP sensor will correctly see the change in mass flow - the airflow meter directly, and the MAP sensor through the increased pressure.

[@andrewleonard9257]

I would presume the airflow between the airbox inlet and exit openings (including through the filter) to be fairly laminar. I would also presume the airflow in the corners of the airbox to be quite turbulent. So does it make a difference where on the box the pressure taps are placed? Near edges and especially corners might give misleading results. Alternatively, if a tap actually protruded into the airstream, it might result in some Coanda Effect. Would it therefore be best to have multiple airbox taps on each side of the filter, and take an average? Also, the filter possibly has the effect of straightening the airflow. Is it possible a more restrictive filter could force more air to pass through the outer edges of the filter, making that part of the airflow higher velocity, and thus effecting pressure and turbulence in that region? Perhaps paper filters are actually a better match to airboxes than the oiled cotton types?

[@JulianEdgar]

Based on my measurements, I don't agree with any of your points. I encourage you to do some measurements yourself.

[@andrewleonard9257]

@@JulianEdgar I will. Have ordered OCPM and will buy a suitable gauge or two.

[@herniagaming]

Does a properly vented intake pipe, ie bigger, straighter path, sucking in from a high air flow area actually improve torque and HP

[@JulianEdgar]

Yes.

[@MrNeutross]

5:00 What you're talking about here, I've also found that to be the case. K&N filters are the worst, almost no measurable power difference but alot more sand and dust into the engine. Just the way the engine likes it, hahaha

[@gregorykusiak5424]

What about opening up the air box inlet? It doesn’t address whatever restriction might exist at the metering apparatus, but it should reduce total systemic restriction, correct? And how does the location of the breather inlet on the intake tract factor into the restrictiveness; does that also lower that number, as it ultimately ends up back in the intake manifold through the PCV?

[@JulianEdgar]

Opening-up the airbox inlet is usually part of fitting a new intake. Doing that *without also ducting air from outside the engine bay* usually leads to a performance loss through (1) breathing hot air (ie air that is less dense, and so contains less oxygen) and (2) picking up air from an area that is aerodynamically not a high pressure area (which in turn leads to a reduced amount of air that is inhaled). I think airflow through the breather is pretty trivial, and so not really relevant to this discussion. (When you do the maths, engines breathe an enormous quantity of air at high loads and high rpm, so the amount that can flow through the breather hose is relatively inconsequential.)

[@gregorykusiak5424]

Julian Edgar ok, what about getting the used air and other byproducts of combustion out of the engine; that should equally be non-restrictive as well, correct? Just optimizing these things should make 20% (maybe?) more power available. Electronics hacks/tweaks might help make the car a similar degree more fuel efficient. So more power and drivability for less fuel, but the real efficiencies and optimization come aerodynamically? And driving style for a road car.

[@JulianEdgar]

Not quite sure what you are asking. Exhaust modifications to give better flow have been being done on cars for about 100 years. Power gains from exhaust and intake modifications depends on how restrictive the originals were (both fairly easy to measure at low cost - see www.amazon.com/gp/product/1787113183). I don't know of any electronic engine modifications that will yield a 20 per cent improvement in fuel efficiency. My book 21st Century Performance (now out of print but I have a couple of copies for sale) gives a good overview of intake and exhaust modification. www.amazon.com/gp/product/0947216901

[@Crysmatic]

I learned a new word today. A magnehelic gauge is roughly $100 USD. Can you recommend a 30" H2O model? How well do digital manometers work in your opinion?

[@JulianEdgar]

Digital manometers are OK but harder to read (high speed of pressure fluctuations). Magnehelic gauges are less than that if you look hard - eg right now on US eBay there are a couple with the right pressure range at US$35 each.

[@douglashartney2564]

Hi Julian Great Videos thanks. I have a v8 twin turbo DPF diesel, I want to put in high flow airbox with better paper filter ( more Pleats ). does more air in, let more soot in the dpf can,t put bigger exhaust. or does the mass air sensor only let in what it needs, does it need a professional tune ? Also the resonance I hear about on snorkels with larger air intakes. does it it need baffle/s Does your book cover these type of questions thanks and again great videos.

[@JulianEdgar]

More power = more airflow = more soot in the DPF I would think. Re resonant tuning, etc, no publication in the world does it in sufficient detail for what you want. The only way is via very careful testing - quite possible on the road (and covered in one of my books).

[@douglashartney2564]

@@JulianEdgar Thanks Julian, which one of your books are you referencing. is it modifying the aerodynamics of your road car or is it another edition, thanks for the reply.

[@JulianEdgar]

It’s the one on testing your car modifications. You could use an accelerometer to plot the engine’s torque curve with the intake in different configurations. Easy, cheap, accurate and takes into account real aerodynamic and resonant tuning aspects.

[@douglashartney2564]

@@JulianEdgar Thanks Julian Will look it up and purchase Thanks Again

[@JulianEdgar]

This book - www.amazon.com/Optimising-Car-Performance-Modifications-aerodynamic/dp/1787113183/ref=mp_s_a_1_9?qid=1640676760&refinements=p_27%3AJulian+Edgar&s=books&sr=1-9

[@lauriedooker1031]

Julian does your books go into how to make the ideal shape air-box ?

[@JulianEdgar]

kzbin.info/www/bejne/a5rNnmNqeLh_Y68 is one I made. Flows very well. Just use a truck filter if more flow is needed with this design.

[@lauriedooker1031]

@@JulianEdgar as with fully ducted and vented heat exchangers would it be Beneficial to use that same principle with a filter system ?

[@JulianEdgar]

@@lauriedooker1031 Sorry, not sure what you mean.

[@lauriedooker1031]

@@JulianEdgar any Benefit by changing your air filter tube shape to a double cone shape ie, Cold air side opens up with cone. to expand the air into the air box and then another cone taking the filtered air away to the engine inlet. Cones being diameter of say your air box tube down to engine inlet diameter tube.Not Symmetrical but somewhat diamond shape from side axis. . ? Could something like the above improve efficiency?

[@JulianEdgar]

@@lauriedooker1031 Perfect thing to test, using the engine as a flowbench. Easy and cheap to do.

[@alexgrzeskowiak5328]

Does it make any difference if the air filter is at the end, or at the beggining of an intake?

[@JulianEdgar]

No difference.

[@limbeboy7]

only problem is usually the closer you get to the engine intake the hotter that area is. fo the filter might not last long if you place it right next to the engine

[@JulianEdgar]

@@limbeboy7 Lots of cars have the filter close to the engine - some have it mounted on the engine itself in fact.

[@limbeboy7]

@@JulianEdgar show me, because either its an expensive filter. Cheap plastic filters need to be mounted away from the intake manifold in order not to be degraded by the heat

[@JulianEdgar]

@@limbeboy7 Lots of engines! Here's one - upload.wikimedia.org/wikipedia/commons/thumb/8/86/2004_Subaru_Impreza_Sport_Wagon_EJ15_engine.jpg/1920px-2004_Subaru_Impreza_Sport_Wagon_EJ15_engine.jpg

[@tiitsaul9036]

I measured pressure drop in my cars air filter last night. Dirty old filter caused less than 1” of water at full load. So yeah upgrading filter alone is pointless.

[@JulianEdgar]

Yes, I have never measured a standard paper filter that had a higher pressure drop than 1 inch of water at full load (unless of course engine power had been increased by a lot).

[@andrewleonard9257]

@@JulianEdgar Does that mean that for all intents and purposes, the only difference between OE and aftermarket filters, is the filtering ability? Are there no crap filters at all, in terms of flow? Are there performance filters with inadequate filtering?

[@heitorbernardes7977]

@@andrewleonard9257 in fact, most conic filter you find on the market have less filtering capabilities then the OEM... You need to focus on where the filter gets the air, not on it by itself.

[@andrewleonard9257]

@@heitorbernardes7977 Okay. I have a flat K&N, bought for less than twice the price of the equivalent paper filter. Thought it was good value as can wash and reuse several times or more. Imagined I would get a bit more flow. Should I be worried about its filtering capability?

[@heitorbernardes7977]

@@andrewleonard9257 if it's an original K&N, that's a good brand. You need to be aware of the cheao stuff that ricers use.