Hey guys and gals.

I was curious as to whether anyone actually has figures for air throughput on the air intake, possibly from just around the MAF/Air Filter. I have this crazy idea that a pc fan putting out around 100cfm may be useful in a cheap semi-charger option. Or failing that I may be able to possibly create something to go in the air intake that will increase air input. This being the basis of turbo and super charging, I thought it might be interesting to get a cheapo charge option. Certainly fun to see what sorta results I get.




#Edit: No way are ya getting a 2500cfm fan. <-- Does anyone know how to make this small?

the sprintex blower is rated to 800cfm...

how is a pc fan going to make 2500cfm?

man this thread will be closed in like 5 seconds, another electric super/turbocharger arrrhhhhh... lol

the sprintex blower is rated to 800cfm...

how is a pc fan going to make 2500cfm?

man this thread will be closed in like 5 seconds, another electric super/turbocharger arrrhhhhh... lol

Yeh, dude this is just not possible, even if u can get a fan rated at 800cfm+ :doubt: then you would need something larger than your battery to power it!!

Yeh, dude this is just not possible, even if u can get a fan rated at 800cfm+ :doubt: then you would need something larger than your battery to power it!!


It was my thought too. But there is a motor at Jaycar (great electronics store) 12V 1A and output of 14500RPM. With a 120mm fan cover hooked up on the end, thats some fairly insane air throughput. With even efficiency down the tube (50%) thats still like 3000CFM.

PC fans top out at 200 CFM more or less - for high speed 120mm jobs

To put it another way, I don't care whether this plan sounds stupid, crap, etc.

I really don't give a f***** f*** in h*** whether the idea works out or not. I just want stock numbers for air throughput on the intake. I am really interested in this cause they don't document it anywhere.

If ya care to help, reply.

If ya wanna shoot down the idea before I even try, pm me so I can ignore you.

To put it another way, I don't care whether this plan sounds stupid, crap, etc.

I really don't give a f***** f*** in h*** whether the idea works out or not. I just want stock numbers for air throughput on the intake. I am really interested in this cause they don't document it anywhere.

If ya care to help, reply.

If ya wanna shoot down the idea before I even try, pm me so I can ignore you.

You can have a rough guess at it by multiplying the swept volume of your engine by the engine rpm.
eg. assuming 100% volumetric efficiency - a 3 litre engine @3000 rpm will suck 9000 litres per minute. Now 1000 litres = 35.3 cubic feet so 9000 litres = 318 cfm.

So if you can find out the average volumetric efficiency of a car engine you can get a rough figure to work with.

You can have a rough guess at it by multiplying the swept volume of your engine by the engine rpm.
eg. assuming 100% volumetric efficiency - a 3 litre engine @3000 rpm will suck 9000 litres per minute. Now 1000 litres = 35.3 cubic feet so 9000 litres = 318 cfm.

So if you can find out the average volumetric efficiency of a car engine you can get a rough figure to work with.


Thanks for that informative post. Would an increase of say 10cfm make a major difference? Does every little bit count? Does anyone happen to know the air/fuel ratio on a stock Magna TE 2.4L?

Thanks for that informative post. Would an increase of say 10cfm make a major difference? Does every little bit count? Does anyone happen to know the air/fuel ratio on a stock Magna TE 2.4L?

Unless you can rig up a fan which can flow more air than your cars engine at WOT - it will end up being a restriction.

I've seen a car with one of these setups loose power on a dyno........ if that doesn't convince you that it's a waste of time and money, have fun :D

The only possible way of doing this that I have seen so far is to step up the voltage into an airconditioning blower off a large vehicle - we are talking 36V into a 12V 10A fan with nylon blades, you can imagine what would happen if it decided to follow the laws of physics.

The way that a few of these ebay 'plans' suggest you do this is to use adittional batteries and relays, hooked up so that when you need 36V (or 24V - I would say 36V is an instant smoking mess) the batteries are placed in series with the car battery, and when you need to charge they are placed in parallel.

A mate and I did this once on an old paddock basher gemini - using crappy 50Kw isuzu engine, a skyline blower fan - running in a suck through configuration (ie. carby was mounted on the blower fan intake, outlet went to the intake manifold) powered by a 24V truck battery - it was triggered from a throttle switch (a microswitch activated when the throttle was opened a certain distance.

Pinged its tits off, but made a noticible difference, especially when timing was pulled back a bit. Very dangerous, very stupid idea - I wouldn't recommend it.

There was years ago, an article in FF&R or Hot4's on a battery powered supercharger that drew 150A @ 13.8v (2KW!!!) from a seperate yellow top Odessy battery. Used what looked like a vortech blower internals, but with a mongo stepper motor/3 phase motor fitted to the end - it had 3 wires running it, red blue white, each about 4Ga, running into the control box, and then two massive (2Ga) wires running to the terminals of the battery. It did produce boost (a whole 2.5psi of it) but was expensive ($3K+) and required an uprated alternator.



Cheers
Heath Young

what you need is a 2stroke leaf blower hooked up to your intake system....

google it, you will find something on it, i've read the details before...

but with the computer fan/similar things.... if they worked, everyone would have one

[QUOTE=Scorpion]You can have a rough guess at it by multiplying the swept volume of your engine by the engine rpm.
eg. assuming 100% volumetric efficiency - a 3 litre engine @3000 rpm will suck 9000 litres per minute. Now 1000 litres = 35.3 cubic feet so 9000 litres = 318 cfm.

A small correction to the figures:
Being a 4 stroke engine the cylinders take in air/fuel every second revolution, so you need to divide the 9000 by 2 = 4,500 litres per min.

Fair call Leo11. :bowrofl:

Means you can save money not having to put two computer fans in . :badpc: