Leaf blower???????

[KDillard]

How many psi do most leaf blowers operate at? Would be a cool thing to create a variable speed leaf blower to assit like a twin set up for racing. I do know some blowers blow in excess of 120 mph. Any Ideas? I know this is thinking way outside the box but someones gotta do it. Oo.

 

[JApol]

Actually I saw a video not to long ago about that but with a ricer. The block ended up being well ventilated

 

[Bertram65]

A good gas blower operates at about 190 mph plus wind speed, the problem is volume, they could never produce enough cfm to maintain any type of positive presure once the engine was above idle.

 

[KDillard]

Ok went to homedepot.com and found black and decker has a 230 mph leaf blower. Does anyone know what that would convert to in PSI? This is an intriguing thought to add boost.

 

[lil red cummins]

the reality of this is that the relation of air speed to air pressure in relation to a leaf blower is probably not what you think. 190 mph is a velocity, NOT a pressure.



if you run your leaf blower wide open and then put your hand over the end, you can stop the flow of air very easily. my guess is that the air pressure would be more accurately measured in "inches of water". this scale is much more sensitive than PSI. 100 inches of water pressure is about equal to 3 psi.

i theorize that the leaf blower can't even make 3 psi.



i actually did a search to see if anyone rated the "pressure" of their leaf blowers and couldn't find one.



so there really isn't that much pressure from a leaf blower. if someone has a water column gauge, i would be interested in the actual result.



as to whether or not this would help our engines. its got to be better than sucking at normal atmospheric pressure, but not much. once the turbo develops even 5 psi, its probably better than the leaf blower.



my . 02



jim

 

[KDillard]

agreed to a point

Im talking to remove some of the lag. A leaf blower is essentially a electric turbo. If It even gives 5 psi of boost for a launch at the strip or even on the dyno then it would be worth it. There are a few electric turbos on the market now but they are costing 500 dollars??? whats 230mph convert to in cfm?

 

[2Gen3Gen]

I have a back pack Sthil that blows me in circles! Great blower! Not sure but I think it is about 250mph or more. All i can say is after 1/8 of a mile on my driveway, it takes both hands to keep it straight. I had a Husky hand held that wasn't worth a $#@*&. Took 2 hours to do what the back pack does in 40 min. A bit pricy but well worth it. Right around $400 on sale. It is the commercial model.

 

[johncameron]

darn, it looks like a FERD owner has beat us to this trick. Thats why their turbos sound soo cool

 

[rbattelle]

We can calculate the pressure ratio across the blower using a form of Bernoulli's equation. Without boring you with the details of the calculation, a leaf blower operating at sea-level with an output velocity of 200 mph is producing a total pressure at the exit of 15. 4 psia, or 0. 7 psig (what your boost gauge would read).



Someone check my math...



-Ryan

 

[KDillard]

anyone want to build a test box? I figure someone would have a boost guage laying around could build an air tight box and see.

 

[TravisG]

I think Dockboy uses a leaf blower. I don't know how well it works. But I bet he will put down a pretty big number at Kaufman's this weekend. Oh yeah he drives a Ford by the way.

 

[BigGunZ]

It wouldn't work. As someone said above the problem is volume. MPH is more a function of nozzle orifice size and pressure. A leaf blower has pretty good volume until you restrict it's output by trying to increase pressure... you can litterally reduce volume to zero by blocking it with your hand. I use my electric leaf blower to fill up an inner tube that I tow behind my boat. It's a 200 mph unit and it still takes 2-4 minutes to fill it up.

 

[KevinWatts]

http://videos.streetfire.net/iPlayer.aspx?fileid=AB544E3B-5DFF-416D-9CFD-A1AD23CA9564

 

[BigGunZ]

http://videos.streetfire.net/iPlayer.aspx?fileid=AB544E3B-5DFF-416D-9CFD-A1AD23CA9564

The only reason you're seeing an effect is because the car is sitting stationary on a dyno and the leaf blower is likely only eliminating pumping losses. On a turbocharged large displacement engine such as the Cummins, I highly doubt the leaf blower, capable of maybe 5 psi on a good day, can keep up with the turbo pumping 30 psi. You have to ask yourself... how much of the gains in that video were the result of not having a filter and airbox to contend with. I can easily show a 10-20 hp increase on my Z06 between dyno runs, simply by pulling the filter and running an open MAF

 

[KevinWatts]

May be, but they get an A for thinking outside the box.

 

[BigGunZ]

May be, but they get an A for thinking outside the box.

Absolutely. I think it's pretty funny. It has the potential to work but one would have to find a leaf blower capable of exceeding the displacement of the engine it was trying to feed. A HPCR at 15 psi has a theoretical displacement of 11. 8 liters... that would need to be one heck of a leaf blower. I can easily see that on a normally aspirated small displacement motor that it would be more plausible.

 

[Babyfat]

if your going to do it why put a wheel blower in the back and pipe it up



230 mph which means nothing but 2500 cfm which means alot (wheel blower)



230 mph 400-600 cfm (handheld blower)

 

[BigGunZ]

if your going to do it why put a wheel blower in the back and pipe it up

230 mph which means nothing but 2500 cfm which means alot (wheel blower)

230 mph 400-600 cfm (handheld blower)

Lets take this math a bit further...

I'm not sure that 2500 cfm is very much in the context that a HPCR at full boost is displacing almost 18 liters for every crank revolution. Now spin the engine to 3000 rpms. That's 54,000 liters per minute. At that rate, a Cummins can eat a leaf blower for lunch.

 

[betterthanstock]

The Holset at full spin produces about 100 hp worth of airflow.

Imagine the size of the electric motor, blower, battery and alternator to make it work for more than 2-3 seconds per hour. Also the robbing of engine power to recharge such extra battery. You'd be better off powerbraking your automatic to build up the boost. That doesn't work for passing though. Maybe you should consider nitrous oxide until boost builds up, and then a box with the off boost fueling turned all the way up to smoky. Then as soon as the boost build up, kill the nitro, or you may kill your engine turbo, etc.

I am not sure if the sudden exhaust pressure rise would not blow the stock turbo in short order, but other than that this should work for eliminating most lag.

 

[rbattelle]

Maybe you should consider nitrous oxide until boost builds up,

Or, strap a very large supercharger to the engine to provide boost while waiting for the turbo to spool. [As a side benefit, you could build an intake above the supercharger exactly like the one in Mad Max... super ]



-Ryan