Hey, well I was thinking last night, and I got an idea. I was reading up about the w124 ram-air mods, and I was wondering how many CFM the engine draws in? I was thinking why not add a fan to the intake hose itself. I know you can pick up a 12 volt 500+cfm fan for about $20. You could then attach this to where the intake "scoop" on the w124 is, and have all the air you want, at any speed. Are there any problems with this system? Would it work? Thanks.

There are companies already marketing such a product. Visit this one

http://www.roarinc.com/4turbine.html

I have been interested in one of these but just have not followed up on it.

Badinfo,
i have considered this inthe past as a less exensive way to produce more compression in an internal cumbustion engine.the reason this modification has not been used by engineers and performance guru's is the power drain. believe me there are some great (compact) 12v fans that produce excelent CFM but the problem is the resistance curve. even if your alternator was to just power your intake fan it would not be as efficient as a belt driven supercharger. mechanical to electrical to mechanical is not as good fo a connection as mechanical to mechanical. Although, i did read once about a turbo charger that had a motor in it that gave the turbo a kick at low RPM's and generated electricity at high RPM's, not a bad idea! Keep that brain working Badinfo and maybe you'll invent something. Goodinfo??
Good Luck!
Adam

__________________
Current Stable:
01 ML55 AMG
92 500E (a few mods)
87 300E (lots of mods)
00 Chevy 3500HD Diesel Box Truck
68 18' Donzi Marine
06 GT i-Drive7 1.0 Mountain Bike (with GPS!)

PREVIOUSLY OWNED:83 300SD, 87 420SEL, 88 420SEL, 90 420SEL, 86 560SEL, 86 190E 2.3-16V AMG, 94 E320

Hmmm... excellent excellent... thanks for the help guys. Now, just as a side note, does anyone know how many CFMs the 300E's engine would theoretically draw in at full throttle? I have a couple of fans sitting around, a couple of free weekends, and a tingling for some ghe[TT]o hacking... I mean, I agree with the whole idea about mechanical being more efficient, but...being 16...and broke...I figure its worth a shot...

Badinfo,
I think thats great that your going to try it. i would like to hear about your results when you get it installed. I am not shure what types of fans you are going to try but let me suggest using an induction fan from a model airplane. Electric driven ofcourse. with a high RPM motor you could generate some useful pressure. an assembly like this would cost you $30-$60 at a hobby store. A configuration like this would cost less than the one marketed above in 2phast's post and has interchangable parts. I am not sure what volume of air the M103-104 engine draws at full throttle but you could estimate it with math.
Good Luck and God Bless America!
Adam

I agree with the trial of a ducted fan from R/C aircraft. Here is your source. http://www.towerhobbies.com

Found some info there:

http://www2.towerhobbies.com/cgi-bin/wti0001p.pgm?Q=1&I=LXW938&P=7

http://www2.towerhobbies.com/cgi-bin/wti0001p.pgm?Q=1&I=LXW910&P=M

Your only problem with this setup will be the voltage and current requirement. The easiest solution would be to wire two in series.

While you are experimenting, a lot of ducted fan RC engines use gas motors to power the fan. I thouht "Eureka, an auxiliary gas lawnmower engine to drive a supercharger through a magnetic clutch".

I thought that might save power from the main engine and max out performance, so I did a search. Some equally nutcase Rolls Royce owner already went down this improbable path 75 years ago on his 1925 Phantom 1 7.7 liter convertible! (He was so happy with the conversion, he gave the design engineer a straight 8, 2 liter Bugatti!!!!)
http://rroc.org.au/library/31hc_sheila.html

Quite a handful of a car!

__________________
John

2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)

Click to see 87 300E

It would be interesting to design something that only powered the fan when you needed it. That would reduce the electrical drain which has to be made up by turning the alternator (which then reduces available power).

That would require more ductwork unless the fan assembly would pass adequate air volume when not turning. Otherwise you have to have some kind of bypass flap to allow air in when the fan is not turning.

Maybe you need an electrical switch under the gas pedal to power up the fan when the pedal is floored. Some cars use a similar principle to cut out the AC compressor under full throttle conditions.

Maybe you should consider nitrous oxide injection?

Ken300D

Hehehehe, NOs, I wish. I've got the plans rigged up for an RPM monitoring system using a couple of ICS, im thinking I can have the thing spin up at near full throttle pretty easy, and then I will add in an on/off switch. But yea, I like the idea of the airplane fan. I think if I were to mount the engine on the outside of the intake manifold, and then run a chain down to the fan blade, I could have adequate airflow when the fan is turned off. What I have right now, and with what im just gonna rig up a little tester device is a square type fan electric ball bearing fan that has the motor iside the fan blades. If you don't know what im talking about, just look at a fan in your computer. Same idea, except this one moves about 500CFM, and puts out like 68 decibles. Im thinking I will, temporarily, just cut off some funnel pieces in order to duct the air through the fan, which is actually a bit larger than the intake hose, and then give it a shot. If I can actually notice a difference, im gonna try out something more "professional"

Alright, I did some searching, and found out that the Benz will need less than 400 CFM at 7K RPM, so I should be fine. Now, I just have to wait for the homework to stop... and I should be good to go! Hmm... and I was thinking, what if I just put a small motorcycle battery in the car, and used that to run the fan only when I needed it. That way, when the thing gets drained, I could just remove it and charge, and then be good to go for another couple hours of hard racing...

Badinfo,
Although a brushless motor is verry effieient, a muffin fan generating 500CFM will drain a motorcycle battery faster than you think. i would estimate about 10-20 minuites of useful voltage. if your going this route i would suggest two seperate intakes on your air cleaner housing with a 500 CFM fan on each intake line. ran directly off your main battery. This would give you about 1000CFM to work with. This configuration may generate useful boost pressure. I am interested in your muffin fan. what are its measurements, who is the manufacturer? Looking foward to seeing your results!
Good Luck!
Adam

maybe I am not thinking about this long enough,,,but...if the fan ran constantly at, say, 500cfm would that not create havoc with your fuel mixture? At idle you get X fuel and X air ( fuel delivery being generally well controlled by the computer, throttle position sensor etc etc. With forced air, I would assume the Fi will enrichen to equal the air quantity...etc etc. I need to think about this...but air flow should be in relation to fuel delivery. Would the fan actually obstruct airflow at w.o.t on the open road?
Superchargers and turbos are sequential - the faster the engine turns the faster the SC or turbo spins, delivering more air.
It's late - now I'll be up all night...rats!

Well, I see your point. And actually, that is why I posted in the first place. I didn't know if the "forced induction" method would mess up my car, and quite frankly, I still don't. If I had an electronically controlled engine, I would say that the ECU could compensate, but, unfortunetaly, my 300e only has an ECU to controll the emission, otherwise I would have changed the chip for more power a long time ago. As far as obstructing the airflow, I think that this fan has enough blade clearance to allow adequte flow under full throttle. I hadn't even thought of actually gaining usable boost pressure, I just wanted to feed my engine enough air so that it would be "happy" But, I just found out last night that my 500CFM metal fan doesn't work anymore :-( . It was just some no-name fan that I got off a computer junk store for like $5, and I guess thats why it doesn't work anymore. So now I have 2 options, I can either go and buy the airplane prop setup, or I have found these Nidec 350CFM fans, which I was thinking I could run in a back to back turbine setup, thereby increasing the pressure of the air. When I did the engine usage calculations, I took into account for a 3.2 litre engine running at 7k RPM, so that 400 CFM number I posted earlier had a safety spot, but, considering that my engine is a 3.0 litre, and shifts at 6k rpm, 350 CFM should be plenty. If I can get this to work out, im thinking the dual intake setup used for ram-air would be a candidate for modification with another fan. But yea, http://www.nidec.com/dcfansquickguide5.html its one of the last fans on the list, I just can't find a local reseller....

Shear CFM is not enough. What you need is the ability to deliver CFM with a pressure differential great enough to be effective. I seriously doubt a muffin fan would be able to do much of anything at all.

You could easily tell by putting your hand over the inlet of the fan and seeing how much effort it takes to take your hand away.