Ducted Brushless Fans for boost?

AlexLTDLX

AlexLTDLX

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Do you all think it might be worth trying something like these:


I don't think they'd make a lot of boost, but maybe stacking several together might actually be worth something; particularly relative to the low cost. Do you think it's worth exploring? It'd be very easy to install....
 
at first I'd say no. but no one thought what you did would put a Ltd in the 9s.

at the bare minimum it could be the best cold air intake ever?
 
I like this idea. I have a 3.6 Challenger and live at 5000 feet. I'm looking do do something to just offset the altitude difference from sea level. With my current cold air intake setup, this would be easy enough to test.
 
Please do so - and if you do, I'd love to make a video with you about your results! Just let me know here in this thread.
 
I don't think it'll make enough boost to make intercooling or injection worthwhile. On the other hand, I've always had a thing for Jaguar sedans - particularly the round eyes. One day...
 
When I'm ready I'm going to try the 105mm fan. That one is 4.13 od, and my intake tube is 4.25 od, so easy enough to just clamp down on it. The thrust is less than 1kg different between that and the 120, and the 120 would be much harder to fit. I just need to make sure my IAT sensor doesn't pop out under pressure. Other than that it's easy enough to add a large power cable from the fuse box on the passenger side inner fender area. I'll use an arming switch and a switch at the gas pedal for full throttle activation. I really like the idea of it being "instant on" and providing full flow at any engine RPM.
 
When I do the suspension rebuild I'm swapping in a Hellcat 3,70 diff and axles to replace the stock 3.06's. That will help get the engine up to where it makes good power (4000-6400) much quicker. The rear of the car is getting all poly bushings, the front will be stock for now as there are no poly bushings yet for the newer chassis - 2011 and up. I'm also doing a bigger rear sway bar since it's not easy to replace the bar without dropping the rear cradle anyways.
 
mcm89434 said:
When I do the suspension rebuild I'm swapping in a Hellcat 3,70 diff and axles to replace the stock 3.06's. That will help get the engine up to where it makes good power (4000-6400) much quicker. The rear of the car is getting all poly bushings, the front will be stock for now as there are no poly bushings yet for the newer chassis - 2011 and up. I'm also doing a bigger rear sway bar since it's not easy to replace the bar without dropping the rear cradle anyways.
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Might be advisable to find out the flow rate before purchasing it. Putting any restriction on the front end could possible stall the blades.
 
Maybe for Ram Air. They have plastic blades and big clearance and with a 3/4 inch rear hole on a torque tube using a 70mm fan more air flows out the intake than the hole.
 
Doug Fir said:
Might be advisable to find out the flow rate before purchasing it. Putting any restriction on the front end could possible stall the blades.
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Just about impossible to get any info other than it putting out about 17 pounds of thrust. My bigger concern is it being Chinese, and if the blade were to come apart it could jam the throttle open or be sucked into the engine. Still researching............
 
In my opinion ducted fan wont be that good because they are designed to create trust not pressure and flow..
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To have good pressure you need a large central hub and overlapping blades..
1701923632061.png

I bought one of the latter to see what pressure it would give out of interest.


 
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AlexLTDLX said:
Do you all think it might be worth trying something like these:


I don't think they'd make a lot of boost, but maybe stacking several together might actually be worth something; particularly relative to the low cost. Do you think it's worth exploring? It'd be very easy to install....
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I wouldn't expect much.

Your drag racer pulls ~36,000 Watts pretty steadily, with peaks of about 38,000 or a little more, as I remember. That RC airplane "propeller" for lack of a better term, is rated to draw 12V * 120A = 14400W, about 40% as much. Off hand, I'd guess that boost is proportional to the square of the power to the compressor, just because boost is measured in pounds per square inch. If I have that right then squaring the power inputs of both compressors, the square of the ratio of the propeller's power draw divided by what your compressor draws is 0.40^2 = 0.16, predicting about 16% as much boost, not 40%, so roughly 1 or 2 psi.

If I have that wrong and the proportionality of boost to power input is linear, not quadratic, then the results could be really impressive, especially on some small to medium sized cars. But that seems too good to be true.
 
mcm89434 said:
Just about impossible to get any info other than it putting out about 17 pounds of thrust. My bigger concern is it being Chinese, and if the blade were to come apart it could jam the throttle open or be sucked into the engine. Still researching............
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17 pounds of thrust does look good at first, but I think it would disappoint. I see "Maximum thrust" listed as 8.6kg, which is about 18.92 pounds. Looks good so far. But then, the 120mm diameter means its radius is 2.3622 inches so its surface area is about 17.5 sq in and the pressure works out to about 18.92 pounds / 17.5 sq in = 1.0793 pounds / sq in. I guess if the only other expenses are a bit of silicone hose and a couple of hose clamps it's worth checking, but I wouldn't get my hopes up.
 
It's very impressive what that little fan can do. Electric motors have come a long way. You could certainly make a full power tiny leaf blower with that. I think it was Mighty Car Mods plumbed a bunch of pretty decent leaf blowers onto their car and it made no difference.
 
SilverBullet said:
17 pounds of thrust does look good at first, but I think it would disappoint. I see "Maximum thrust" listed as 8.6kg, which is about 18.92 pounds. Looks good so far. But then, the 120mm diameter means its radius is 2.3622 inches so its surface area is about 17.5 sq in and the pressure works out to about 18.92 pounds / 17.5 sq in = 1.0793 pounds / sq in. I guess if the only other expenses are a bit of silicone hose and a couple of hose clamps it's worth checking, but I wouldn't get my hopes up.
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It is slightly better than that PSI because you didn't remove the central hub from the 120mm area... Not that that would change the number significantly. The interesting thing is that the quoted thrust numbers never tell you at what flow rate, it certainly wont be 0 flow rate.
wayland said:
It's very impressive what that little fan can do. Electric motors have come a long way. You could certainly make a full power tiny leaf blower with that. I think it was Mighty Car Mods plumbed a bunch of pretty decent leaf blowers onto their car and it made no difference.
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I know them and this episode well... they didn't need to install them on a car to know they weren't going to help.. they could have simply looked at the specs of the battery leaf blows to know they were FAR to gutless to ever make boost.... Still they wanted to make a video, which they did and got alot of views..
 
It takes power to suck that air into the engine/supercharger... if you do it with an EDF you'll get that energy back at the wheel. But, as mentioned previously in the thread they don't make much in the way of pressure. Going from a vacuum to even a slight positive pressure can only help (unless you create a restriction) and sizing it just above what your current CFM needs seems like the way to go, as again, they don't make much in the way of pressure.
 
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