conceptual thread- poor man's supercharger?

[tim]

My other hobby is remote control aircraft. Over the past few years, the use of brushless motor technology has really taken over. For example, I have a 5oz brushless motor operating on 12v and 25A that puts out 5lbs+ of thrust at 80% efficiency (i.e.: watts in/watts out). It does this on a 10in prop.

I know others who are using ducted fans with scale jet aircraft that are flying at 10 lbs. Look at this link and scroll to the bottom of the page to get an idea of what I'm talking about- http://www.hobby-lobby.com/ductfan.htm

That's alot of thrust. 12-15 lbs of deadlifting capacity with the pitchspeed (how fast the air behind the prop is being pushed) at 80mph+

Now I know what you're thinking- you're not going to get 12 lb's of boost out of an electric motor.- true But you're not going to have a "turbulator" either.

So what if you replaced the air flow boot from the MAF to the Air Filter with a custom ducted fan. Like a straight tube with a K&N cone filter on the end, and a fan in that tube, with a pinch point(a narrowing section) in front of the MAF connection so you would develop some pressure. Let's not worry about where you're going to get the current from yet. You'd have something wouldn't you?

[632 Regal]

but wouldnt you have the same problems as the turbo boys? Fuel curve customization and timing curves and all the motronic mess?

[tim]

I don't know. We're only talking about a couple pounds of pressure. Enough to see gains, but probably not enough to create a bunch of back pressure and within the tolerances of the stock MAF sensor. I suppose it would be similar to running a large hood scoop. But, I don't know.

[632 Regal]

I would try it if it was only a couple lbs of boost, it also would only be applied at full throttle so that may be a whole different deal. Hood scoops do add power but back then we would just rejet the carb and timing, this is computer controled.

This might be sweet!

50 bux and 50 HP just pop on...hmm

[AllanS]

How much air does it move? cfm? Thomas Knight is doing something similar to this, but with rootes type superchargers. It's powered by large capacitors, which recharge while you're off throttle. From what I've read, it seems to work well, but for the money I'd rather let the exhaust do the work.

For comparison, a Garrett T25 (.60/.62) puts out 405 cfm. An s trim to4b compressor on a t3 turbine housing puts out 650.

[tim]

Yeah, actually I was thinking of just powering it directly off the alternator, with a shunt switch into the cabin. Not something I'd drive around with all the time, but it might be fun for doing a 1/4 mi time, or shaming a mustang etc.

[tim]

How much air does it move? cfm? Thomas Knight is doing something similar to this, but with rootes type superchargers. It's powered by large capacitors, which recharge while you're off throttle. From what I've read, it seems to work well, but for the money I'd rather let the exhaust do the work.

For comparison, a Garrett T25 (.60/.62) puts out 405 cfm. An s trim to4b compressor on a t3 turbine housing puts out 650.

I'm only guessing here, but maybe 150-250. My ME-109 at wide open throttle is comparable to a good size leaf blower, and it's not even ducted.

[andyman32]

Wow, really cool concept tim. Even if you just pick up 20 or 30 horses, that's the cheapest 30 horses you'll get anywhere on the car.

Would the computer automatically adjust the air/fuel mixture to compensate for the increased airflow? Or would you need a custom-programmed chip?

[AllanS]

Hey Tim, I've got a question for ya... when my dad died, about 16 years ago, he left me these 2 model planes (one of which looks just like your 109, but brown with a blue bottom)... they're balsa wood frames, with paper over it, and then painted. Well, the paper is all brittle and falling apart, and if you so much as touch it your finger will go through... Do you know anything about that type of model, and maybe what it would take to redo it? Like, what kind of paper (if at all) should be used, paint, etc.? Could an actual engine and controls be added to it?

[AllanS]

Let's say for arguments sake that these things put out 300 cfm (impossible, of course).

That's comparable to a t25- a very small turbo. If you put one on even a 525i, it would spool up fast, and run out of juice, fast.

I could see this on a motorcycle or some other small displacement engine, MAYBE, but not on a 4l v8!

Also, it wouldn't be worth the money spent on tuning, if the reason for buying one is their cheap price.