Air/Fuel question.

[Shurup]

Air/Fuel really crazy question. And more...

Well, I don't even know how to start my qestion.
Lets say I came up with a crazy idea of installing a fan into air intake tubing. Fan's RPM can be easily varied, so at endine idle speed the fan wouldn't change the amount of air entering the engine and at WOT it will pump more air into the engine (kind of imitating a supercharcher ). Now, will the computer add more fuel at the WOT? Or I will run a week mixture of air/ruel. What can really happen if I do that?

And some other quick questions.
Sometimes I get 14 mpg on one tank and sometimes 12 mpg on the other tank. I do a lot of driving (most of the times in 4x4) and I don't change my driving habbits so I guess it has somethging to do with gas itself. Am I right?

I know 12-14 mpg on V6 is ****ty but I need to do wheel alignment, but before that I have to replase all 4 balljoints (will do that when it will be warm here ). How much can I expect increasing in mileage after I do balljoints/alignment?

 

[Shurup]

By the way, I got 112K miles on my truck and the engine runs very smooth. Previous owner did a regular maintanence on this truck and it is in perfect condition. I bought it with 100k miles on it.

 

[Alec]

Please forget any thoughts of putting a fan in your intake. It won't work, trust me it's been tried.

As for the mileage, having less rolling resistance (good alignment and balljoints) will help. But most likely it's that you drive around in 4x4 all the time, I hope you don't do that on dry pavement.

 

[Shurup]

I don't have ANY dry pavement around here where I live. Not yet, not yet...

Thanks for the answer about the fan thing. I was almost sure it won't work for the reason that at WOT amount of air comming through the MAS will cool it down to the outside temp, so more air comming through it won't cool it any more and so it won't MAS's resistance any lower. That must be the reason fan thing won't work. Just asking.

 

[Alec]

It's not a matter of temperature, but no, it won't work

 

[Shurup]

And why it won't work then? I am not bugging you, but just trying to understand why. If I install a perfornance air filter, perfornance MAS sensor, perfornance TB, then more air will enter the engine therefore slightly increasing HP. Why would't it work with the fan thing? I don't expect to get increase in power as much as from installing a supercharger, but there should be some niticeble increase.

Now the question for you Alec (you have a supercharger so you know more about them then me). What else the supercharger does beside pumping more air into the engine?

 

[Alec]

The fan may work at lower RPMs, like below 3000. It may even make 1-2 lbs of boost, which you'd need a chip or adjustable fuel unit to compensate for. However, past that it will just be a restriction in the intake and you will lose lots of power.

I'm sure you've seen those fans on ebay, they just don't have enough power to help a motor.

I have a group of friends that dyno tested some huge leaf blower fans a while back. They did make 20-30 hp power gains in the low end, however they lost more than that on the top end. Besides the fact that the power required to run a fan like that reliably would require a new alternator and a dual battery setup. Also they're very loud.

But yes, basically all a supercharger does is compress the air going into the motor and force in a bunch of it Unfortunately, this also creates heat which is remedied by an intercooler. I don't have an intercooler though On the flip side, if I did and was making lots more power, I'd need a new tranny!

 

[Aaron 4.6]

Bear in mind that it takes power to make power. A blower making 6-7 psi is probably requiring a solid 20-30 horsepower to compress the air. No fan is going to provide that kind of power. Fans push and pull air. Compressors crush air.

A supercharger doesn't do anything besides move air and generate heat. The more you do of the first and the less you do of the second the happier you will be.

 

[Brandons]

Does that mean my 4500rpm blower fan be usless in the truck?

 

[Kadarom Douhrek]

Originally posted by Brandons
Does that mean my 4500rpm blower fan be usless in the truck?

No, it will be less than useless, it will be a hinderance.
Fans move air from one area to another.
Turbos/Superchargers compress air allowing more of it in the same space.