Air Filter Box Mod
#21
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checkered stuff is there to cancel vibrations (large plastic areas tent to move) caused by intake pulses... M5 doesnt have them because deeper engine sound is there anyways... and besides that great effort to clear them out, think about vortex generators on down side of a dragster wing or shark skin effect... smoother is not always better...
#22
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Originally Posted by StreetPro' post='967323' date='Aug 6 2009, 04:27 AM
checkered stuff is there to cancel vibrations (large plastic areas tent to move) caused by intake pulses... M5 doesnt have them because deeper engine sound is there anyways... and besides that great effort to clear them out, think about vortex generators on down side of a dragster wing or shark skin effect... smoother is not always better...
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#23
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Yeah.....that doesn't sound right? The M5 doesn't need it because it has a deeper sound anyway, huh? So your saying the checkered pattern is to reduce the sound of the engine, or more specifically the intake?
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Originally Posted by v_therussian' post='968259' date='Aug 7 2009, 01:23 AM
I thought turbulent is always not better... ![Think](https://5series.net/forums/images/smilies/imported/think.gif)
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I only studied fluid dynamics back in college so not too sure about aerodynamics. Did I tell you guys I have a Chemical Engineering degree?
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Originally Posted by brabusw209amg' post='968291' date='Aug 7 2009, 02:34 AM
Not really. Turbulent flow is sometimes better. Turbulent flow is good for heat exchangers. When it's for heat transfer and mixing purposes, turbulent flow creates more surface area. So air flowing through an intercooler when turbulent is better but laminar flow in the engine is the best. This is what I deduced.
I only studied fluid dynamics back in college so not too sure about aerodynamics. Did I tell you guys I have a Chemical Engineering degree?![Laughing](https://5series.net/forums/images/smilies/imported/laughing.gif)
I only studied fluid dynamics back in college so not too sure about aerodynamics. Did I tell you guys I have a Chemical Engineering degree?
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As for the turbulent flow, in the case of an intake it is not good, because it reduces the air pressure in the intake, thus reducing the power. The more laminar the flow, the more air pressure; more air=more ignition; more ignition=more power. Sorry about such a layman explanation - not like I'm a Chemical Engineer, or anything
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#28
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I am not saying it is SO... I can only imagine that is serves that purpose- to make the engine quiet... in M5 there is no need for this, you want to hear the engine... same as M52B28 (e36 fl) sengine versus S50B32... M52 has a Helmholtz resonator on airbox to cancel specific (unwanted) frequencies (noise)... S50 (M3 e36) does not have it no matter that it would be easy to add it as well (or even use the same airbox, pretty same size as well)...
and laminar v. turbulent flow- in this case I dont know either for sure, it si not easy to say by looking at it, you would have to run simulations to see how those CFD lines behave (air behaves similar to fluid, so they tend to lean to sides, perhaps turbulent flow generated by those ribs helps to move the whole stream upwards to the filter... hope you see the idea)
and laminar v. turbulent flow- in this case I dont know either for sure, it si not easy to say by looking at it, you would have to run simulations to see how those CFD lines behave (air behaves similar to fluid, so they tend to lean to sides, perhaps turbulent flow generated by those ribs helps to move the whole stream upwards to the filter... hope you see the idea)
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Does this make more power? I think it's hard to say.
Clearly BMW put many hours into the design for a reason. Was it strictly to cancel engine noise? Maybe.. Or could it have been something to do with airflow?
You definetely need to dyno your car and see what kind of results you get. And you need someone's stock box for comparison. This would be the only way to really know if there's actually an improvement.
Clearly BMW put many hours into the design for a reason. Was it strictly to cancel engine noise? Maybe.. Or could it have been something to do with airflow?
You definetely need to dyno your car and see what kind of results you get. And you need someone's stock box for comparison. This would be the only way to really know if there's actually an improvement.