Rotaryphil

These things look cool! Anyone tried one? I wonder how long they last and if they would work as well as they say. 100$ would definatly be worth a 25% power gain.

Would 2 or 3 PSI lean out an engine weather rotary or piston? Would the mass airflow take into account a 2 or 3 psi gain before leaning occurs?

http://search.ebay.ca/search/search....ger&category0=

84stock

iTrader: (5)

They're crap. If they were any good at all you would see them on factory cars.

Rotaryphil

I should sneek one into my dads truck lol

Nick86

iTrader: (1)

Really PSI means nothing here. In an engine PSI is measured with a running engine - this thing could probably pressurize your intake to 3 psi when it isn't running, but not while the car is on. You need to look at CFM.

Rotaryphil

It's hard to tell weather there measuring with the engine running or not. It would have to flow more air than the engine is already inducting. Ether way it probably doesn't increase the CFM of the induction and is a waste of time. Basically "Boost" is a manifold pressure measured over a reading of 29.92Hg standard sealevel pressure.

Rotaryphil

Here is a write up that makes me look very foolish lol

Understanding that forcing more air into the engine will make more power, it stands to reason that if we can place an electric fan in the intake path that will force air into it, we can make more power.

The problem with this idea is that most people who think of it really have no idea how much air gets pumped by the engine during its normal operation. The engine acts as a big air pump and is capable of moving huge volumes of air all on its own. With that in mind, any electric fan that you place in the path of the intake is only going to act as an obstacle to efficient airflow and not provide any level of boost whatsoever. In order to provide boost, the fan has to be able to force more air through the intake than is already being sucked and that's simply not going to happen with some off-the-shelf computer fan or bilge exhaust blower or whatever else you've found or had marketed to you.
If you place something in the intake path between your air filter and the engine and that thing isn't made to be there, you now run the risk of having it break and send unfiltered pieces into your engine, potentially causing catastrophic failure.

Aaron Cake

iTrader: (1)

It's too bad that eBay doesn't have some mechanism to automatically remove scam auctions like this one. A rather simple Bayesian filter could tag auctions as possible crap, then real people could make the final call...

Rotaryphil

It might work if you didn't put it "Inline" with the intake. You could fab separate pipe running to the main intake and run it through that other pipe. Therefore you wouldn't disturb the main flow thus adding CFM to the main induction air, sort of like a Y pipe. It would never produce boost but it would get the intake vacuum closer to 29.92Hg thus making the engine more efficient.
Still a complete scam but that might work lol

P_Lav

They would need a really powerful electric motor to make enough pressure to add power, turbo's spin over 10,000 rpms at times, so they have plenty of power to drive the air being forced in, but a wimpy blow dryer motor? This is a joke.

londonmazda

iTrader: (2)

turbo's spin quite a lot faster than 10,000rpm

85rotarypower

Turbos can spin up to 100,000rpm in some cases, or so I've read. I have really no clue what the actual speed is.

As for this "heater blower motor", it has no hope in hell of ever making any extra power on any engine, it would actually decrease power most likely as it introduces a new restriction in the intake. Its been proven that to make a supercharger that could produce an actual 3 psi, you would need the equivelant of 3 starter motors. One company does actually produce a working roots style supercharger using multiple motors that draws well over 100amps, but it does produce a real 3psi. It can only be activated for no more than 30 seconds at a time, and even that is pushing it most likely.

rx7racerca

iTrader: (1)

Turbos do in fact spin up to 100,000rpm, and are frequently above 50,000. It's not so relevant what they or some fan spins, however, it's how much air they move, and how efficiently. And I seriously doubt any electric motor that can be added to the intake tract somehow is going to be able to flow more air than the big, gas-powered air pump called the engine can suck, so I can't see how any such thing can be more than a restriction. Never mind the extra load placed on the engine thru the electrical system.

londonmazda

iTrader: (2)

some holset turbos are hitting upwards of 140,000rpm :/

B6T

iTrader: (2)

No, "boost" is a measure of pressure over 0psi gage, or 14.7psia, in the intake tract of an engine.

in. Hg (inches of mercury), not "Hg" alone, is typically used to measure vacuum and not positive pressure. 29.92 inches of mercury does convert to 14.7psi. Your statement that boost is pressure 14.7psi above standard sea level pressure (which is 14.7psi) is false. You probably got confused and meant to say that boost is 14.7psia, which is 0 psi gage, or 14.7 psi above absolute pressure.

B6T

iTrader: (2)

And any power gains you'd see from that additional 3psi of pressure would be negated by the addition load from the alternator and the loss in spark energy you'd see while using a device that pulls that much current. Who buys this ****, seriously.

Rotaryphil

Hg is used to measure negative AND positive pressure. There are 3 ways to measure intake vacuum OR boost. All of these are neutral pressure or "absolute" pressure. 29.92Hg, 1013Mb (millibars) or 14.7 psig. They are just 3 different ways of measuring absolute "0" pressure or a neutral intake condition, which varies wherever you are according to height above sealevel, temperature, or if theres a high or low pressure system in your Area. A boost gage in a car is essentially a manifold pressure gage as in aircraft. I'm not sure if automotive gages are automatically compensated for these variables? boost or manifold gages are suppost to account for those variables so you know your actual manifold pressure/vacuum at your given temperature/height above sealevel. When you start you car/airplane the Manifold/Boost gage will immediatly jump down to somewhere below 20Hg as there is a vacuum condition. As you increase power you will become closer and closer to 29.92. As soon as you go above 29.92 it is representing a positive pressure or "Boost" condition in your intake.

B6T

iTrader: (2)

I know how it works. I was just saying that I've just never heard positive pressure expressed in length units of mercury. I've only ever heard vacuum, or amount of pressure below ambient sea level pressure (that is 0 psig, 14.7psia) expressed in those units... not in college thermo-dynamics, not in university thermo dynamics, and not in university fluid dynamics. I'm not saying it's wrong, I'm simply saying that it's just not what I've paid various people in various educational institutions to tell me.