EEB Electric Engine Blower (fan)

[Shadow_Demon]

My bike is a '00 Honda CG, which I know isn't particularly tunable -- This is just to see what results I get, i'm not actually going to do it for an extra .000003 of a HP!! lol

Okay, so hypothetically, if I ram a couple ultra hi-flow 80mm delta fans into the airbox on my motorbike,(Or other type of big CFM fan, they aren't hard to come by)

... I set a relay to trigger when the generated voltage reaches a preset minimum of lets say 14VDC (about 6000rpms), the relay connects...

Right, on the power goes... regulated 12VDC to the twin fans in the airbox, (and to a white LED in the dash -- for finesse, haha!) would this boost power, no matter how small the increase?

Would the rpm's need to be higher? Would shutting the top of the airbox when the fans (butterfly valve) are running make a difference, EG: Not forcing air out the top but into the carburettor.

(I'm currently teaching myself about boost, turbochargers etc -- I'm a mechanic, electrician and engineer in my spare time!!)


Any help much appreciated, it should be interesting to see the results!

[beso]

A Clayton's supercharger eh?

The extra power in a supercharger or turbocharger is proportional to the pressure increase. The supercharger is an air pump and develops pressure by forcing air into a smaller volume. It actually takes a lot of power. A lot more than a little electric fan.The turbocharger revs incredibly fast to build substantial pressure.

A fan is designed to move volumes of air not increase pressure so you won't notice any increase in power. The fan may even restrict the air intake and reduce power.

The turbos and superchargers pressurise the manifold which is made of metal. If you could significantly increase the pressure in the airbox it would blow to pieces.

Remember on of the most common failures in a drag car is the supercharger blowing off the top of the manifold due to the pressure it develops.

[Shadow_Demon]

Great answer there!

Indeed you are quite correct about the turbochargers etc (I can't believe some of them spool up to around 200000RPM's on test -- explains why the wall of the things is so damn thick and strong, not to mention the semi-ceramic bearings and what not!) all that speed on the fins and not an enormous port make for relatively high pressures, i'd love to muck about with a huge Garrett and an even bigger train/truck diesel engine, what a rip!

Babbling guff aside, onto the main event...

Just a hypothetical thing, but thanks for chucking in the additional info, just goes to show -- you can never know too much about anything!

How's about a hefty fan in the exhaust, to suck away all the uber-hot gases, with a straight through pipe (with a small hole near the cylinder? -- Or will that just make it spit flames and deafen me, lmao.) to boot.

I know back pressure is highly important for a two stroke cycle, but would a faster, ducted, fan-assisted exhaust make any difference on a four cycle?

(Carburettor re-jetting, timing, Pulstar iridium spark plugs, methanol, turbochargers and all other tuning aside!)

[beso]

An exhaust pipe is a hell of a place for a fan to try and survive.

Bigger intakes work because the engine has to suck air. In other words the atmospheric pressure is all there is to push the gas flow. Since the amount of fuel air mixture determines the power produced it is important to minimise the resistance to inflow.

Exhaust systems have positive pressure from the movement of the piston so they can operate at higher pressure. A bit of back pressure doesn't limit the power near so much as intake restriction.

None the less a high flow exhaust system does help. Straight through pipes make a lot of noise with very little gain in power if any.

Moreover if you take too much backpressure off the exhaust the rapid rush across the valve can overheat it.

[Shadow_Demon]

Thanks for that,

I appreciate that the exhaust is a perculiar place for a fan, given it's pressure, vibration and heat factors, lots of all three! (That'd be a hard task to mount one anyways, let alone run one what with all that semi-burnt crud all the time!)

Just speaking hypothetical, thanks for your excellent response. :-)