Air Induction Systems, Voodoo, and simple test

[DCColegrove]

So then what is the fix? :o

Well you either straighten the run or force the air flow to uniformly make the turn.

[z31maniac]

Build it, test it, and show its better than the stock setup or any homemade concoctions and people will buy it.

Period.

Be sure to set it up for the M30 AFM though. ;)

[PhillyG]

So then what is the fix? :o

[DCColegrove]

In other words, a smooth silicone intake tube?

No...that makes it worse.

[Farbin Kaiber]

In other words, a smooth silicone intake tube?

[e30frosh]

Function will always overpower form. I'd buy a piece that works better than asthetic pleasure any day.

[DCColegrove]

Over the past decade or so I have seen about a gazillion articles, threads and ads for and about performance enhancing CAI systems. There has arisen this whole culture of Voodoo Science around it.

Most of this is focused on addressing air charge temperature and restrictions in the flow through the air filter to the AFM or AMM. For this there is a very simple test…

Install a temperature gauge and vacuum gauge in the center of volume of the filter or housing it’s self and compare the readings between systems… The lower (closer to zero) the numbers the better. This is a good test but ultimately it means very little.

On the other end of the Voodoo Science spectrum some have come up with ingenious ways to introduce turbulence into the induction system there by to mix up the air /fuel charge for better combustion.

Neither of these bolt on, shove in or what have you “upgrades” produce much of anything (though there is this turbine thing available on eBay that makes this spectacular noise)…

There are some slight modifications that can be made in the stock air box that will improve overall flow at the expense of slight noise resonance… But over all the stock E30 / M20 air cleaner with a clean panel filter element can efficiently flow nearly twice what a stock M20 can use.

Here in lies the rub:



In this area indicated the air flow tumbles and actually reverses its course. And the fix is beyond simple...

I am considering producing an induction system for these old machines…

But alas because it will not look or sound as mean as the current backyard technology I think it may be a waste of effort


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