intake airflow rate

[marmite369]

does anyone know what the cubic volumetric flow rate of our intake is fully open at full revs just needing to know for a project i have potentially got on the go some time soon need a few more bits of info first cheers

[thehunterooo]

i wish i knew, no MAF

[marmite369]

ok been doing a bit of rough research into this and have worked out some proximate values for this.

i believe it should be for a 1.4l car at 4k rpm approximately 100.71 cfm.

i must stress this is approximately using solely my poor maths but using what i believe to be the correct formula's.

the reason i was asking is that in essence ever since i have seen intakes with an inbuilt fan i have wondered how simple it would be to create your own one. the theory to it is quite simple really. more air = more bang right? so the idea to it is to use the same principles as a turbo or super charger but powered but a fan inside of the air intake tubing before the maf (think thats the right name for it(sensor that detects the air flow rate in the intake)) to increase the air flow which in turn the ecu should add more fuel creating a bigger bang?

now iv done a bit of maths again looking into how much more air flow rate would be required to get the flow rate of a 1.8l engine and it works out at a 12% gain. now if my theory again is correct in thinking here you can achieve this gain in two ways. you can either put a fan in that runs at 12% faster rate than the standard intake or you can have a larger intake area point and have a stepping point that basically compresses the air into a smaller point with a 12% size difference between the two and then have a fan again at the beginning of this new sized intake spinning at standard intake flow rate. obviously these fans would need to be variable speed controlled which in incessant could be easy enough control off of the spedo rev counter with a cleaver bit of programming to create the correct speeds across the range of revs.

obviously in this iv not taken into account any negative affects putting fans in or air flow restrictions heat created from the fans power drain created a weaker spark e.c.t.

what is the thoughts of those who are more technical with cars than myself as my basic knowledge is poor even at best so the technical side of things is even worse so i have no idea if this is even correct or even if the theory is correct whether it would actually work. but obviously this is all theory just wondering what people thought to it.

[Petrified.Rabbit]

your not going to have a small enough fan to push the volume of air you need to overcome natural aspiration..

in other words a simple fan will not create boost.

there are times when vacuum "disappears" and having the fan blowing would potentially do something. But short of an electric leaf blower strapped to you engine killing your alternator and battery..

[marmite369]

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=0251104

that is a link to a fan that would achieve the desired maximum air flow

dimensions of 119mm x 119mm x 38mm (would only need to run this at 60% efficiency when the size is taken into account therefore allowing for even more air flow increase)

air flow rate 310cmh

wattage 19.5w (relatively small power drain if you ask me)

spins at 6000 rpm

Supply Current 1800mA.


however on this site you can also purchase just the blades so if you cleaver and know how to calculate flow rates from the size of the fans and work out the rpm needed at top speed on a certain size if would be simple enough to purchase the correct size blades and then purchase a motor again on this site that will reach the desired rpm needed. it's a relatively cheep website to