Topic: ADJUSTABLE MODIFIED STOCK AIR BOX

[quicksand]

Yes I am talking about opening and closing that little slide and hole on the right side of the box, and yes if I open it to far I do lose torque at higher speeds. When I lose that torque at higher speeds I am pushing further down on the pedal to get up to 70 mph and leaning forward. Also having to stay further down on the pedal just to maintian that top speed. Its like with it all the way open I have no passing power. When its a little closed or that sweet spot, I have all the passing power I need and more. As far as a box or scoop on the outside I have not got to that piont. I am actually thinking of running / testing some kind of small air tube or funnel affect. Running it from the front of the jeep to inside the engine bay, just in front of the air box. Trying to utilize that air pressure coming in at higher speeds. You know like when you are doing 55 to 70mph and you feel that air pressure when you stick your hand out the window. Thats alot of pressure. Anyway wierd. Trail and error, fun fun.

[TexWalther]

Yes sir, I have been thru about knee high water or higher, slowly with no problem.

Knee high isn't extremely deep, worry that your design could get you hurt in a water crossing. Entire idea is interesting, would be nice to see some actual numbers, but if you say that everything works alright for ya then congrats on finding a way to get a lil more oout of our puny four-bangers...

[quicksand]

Yes it all adds up, wieght, power, torque, tire size, gears, air/fuel/spark. FUN. Thanks

[Bounty Hunter]

Ref the hole in the bottom of the airbox and the top of the fender, I'd be more worried about water getting in from road spray that from slow water crossings.  You can get plenty of air without having to source it from the wheel opening.

[quicksand]

I have had that hole in the fender well for awhile, Its been thru some heavy down pours and some flooding streets back in houston,Tx. Thus far I have not had any problems. I believe the upper shock mount is acting as a splash shield. Also back in houston I used to go mudding once in awhile and there would be mud everywhere up under the fenders and stuff. That one spot above the shock mount would be fairly clear of mud and stuff. So far so good. Down pours and mud no problem. I understand your thoughts, and concerns. Also my K&N filter stays pretty clean, I clean it about once a year. Thanks

[RT]

Ref the hole in the bottom of the airbox and the top of the fender, I'd be more worried about water getting in from road spray that from slow water crossings.  You can get plenty of air without having to source it from the wheel opening.

With my homemade cold air, i got out of this by having the filter mounted high and essentially ontop of the radiator funnel deal, and having tubing run down under the bumper to form an air-ram at speed, but I left the filter in the engine bay open so it won't suck water.

[quicksand]

Humm, interesting

[quicksand]

Mr bounty hunter, how do I get hold of you privately?

[Bounty Hunter]

Send a PM or email bountyhunter AT sija.org .

[RT]

Yes I am talking about opening and closing that little slide and hole on the right side of the box, and yes if I open it to far I do lose torque at higher speeds. When I lose that torque at higher speeds I am pushing further down on the pedal to get up to 70 mph and leaning forward. Also having to stay further down on the pedal just to maintian that top speed. Its like with it all the way open I have no passing power. When its a little closed or that sweet spot, I have all the passing power I need and more. As far as a box or scoop on the outside I have not got to that piont. I am actually thinking of running / testing some kind of small air tube or funnel affect. Running it from the front of the jeep to inside the engine bay, just in front of the air box. Trying to utilize that air pressure coming in at higher speeds. You know like when you are doing 55 to 70mph and you feel that air pressure when you stick your hand out the window. Thats alot of pressure. Anyway wierd. Trail and error, fun fun.

Ya, I get it, there is a such thing as having too much air, because if you suck more air than you can burn you can generate turbulence in the intake system which makes it run badly in the high end. I used to have a huge filter w/ a really really short tube mounted on my throttle body and I ran into this problem. It sucks gas too. You really want smooth pressurized airflow.

[quicksand]

Yes you are right. Finally someone that has experienced the affect of to much air. Your air intake, air volume and pressure sould be somewhat macthed to your spark and fuel. At least close to working operation, such as some horse power gains along with torque. Also maybe better fuel consumption. I know there is a fine line between more power and burning more fuel with it. Hard to find a good balance.

[sharpxmen]

gotta comment on this one

Ya, I get it, there is a such thing as having too much air

yes, if you don't have enough fuel - why complain for lack of power then, you want more air so you can burn more fuel = more HP

because if you suck more air than you can burn

you burn fuel not air, same as above - you want more air to burn more fuel to make more power. If your AFR is too high (lean mixture) then you need to fix the fuel delivery

... you can generate turbulence in the intake system which makes it run badly in the high end

i agree with you on the turbulence, but is not b/c of too much air but due to poor intake tubing, keep it smooth and no tight turns or sharp angles and will flow just fine (given that is properly sized as far as diameter)

You really want smooth pressurized airflow.

how do you get pressurized airflow in a normally aspirated engine? smooth yeah, pressurized not so much. you're right about smooth airflow thru the intake tubing, the smoother the flow the less pressure loss so more air into the cylinders, so this kind of contradicts the previous statements (and the opposite goes for turbulence, you get pressure drop and lose VE).

Finally someone that has experienced the affect of to much air. Your air intake, air volume and pressure sould be somewhat macthed to your spark and fuel. At least close to working operation, such as some horse power gains along with torque. Also maybe better fuel consumption. I know there is a fine line between more power and burning more fuel with it. Hard to find a good balance.

where to start

effects of too much air: you should begin with checking your fuel system (injectors, pump, pressure, filter, MAP Sensor ,etc) if you think your engine is starved of fuel, remember you added a 4.0L t/b to gain airflow, then you say you have too much air - here's a fix, put back your original 2.5L t/b. Might want to actually start with an AFR gauge on and see what your results are, if you're too lean you need more fuel (and you'll get more power if you fix it, not the other way around as in reduce the air to lower the AFR and get richer mixture).

air volume and pressure sould be somewhat macthed to your spark and fuel

there's no pressure, you don't have a turbo. your PCM will control the spark (not sure how you match your spark by reducing air)

Also maybe better fuel consumption.

you are correct here, if you make less power you will improve your mpg (you drive slower)

such as some horse power gains along with torque...I know there is a fine line between more power and burning more fuel with it. Hard to find a good balance.

actually is not that hard, your O2 sensor takes care of that in closed loop (unless is damaged) - in open loop you'll need an AFR gauge, if you're too lean you need to fix your fuel problem (i probably said that too many times).

the HP produced by your engine is based on the amount of air your engine can circulate in a cycle - the more air the more fuel you can burn and that means more power - the BSFC for your engine and the amount of fuel you burn = HP output. Higher displacement engines will have a higher airflow and that's how they make more HP. If there's no fuel then yes, there is a problem but the fix is not by choking the intake.

[quicksand]

Thats what I said. No just kidding. Yes I got that backwards, I know you burn fuel ofcousre. Now as far as the volume of air coming in from air filter is one thing. Colder better. Availible air better. Can you help me understand why is it when the air pressure coming in before air filter is increased, why do gain horse power and torque ? I know its not turbo. Not being smart or nothing. Its when I allow to much air in it looses pressure and torque. WHY ? Or maybe I just dont get it. But I know what I feel. More power and torque when the air is being pressurized inside air filter box. Huh.

[sharpxmen]

Thats what I said. No just kidding. Yes I got that backwards, I know you burn fuel ofcousre. Now as far as the volume of air coming in from air filter is one thing. Colder better. Availible air better. Can you help me understand why is it when the air pressure coming in before air filter is increased, why do gain horse power and torque ? I know its not turbo. Not being smart or nothing. Its when I allow to much air in it looses pressure and torque. WHY ? Or maybe I just dont get it. But I know what I feel. More power and torque when the air is being pressurized inside air filter box. Huh.

first of all how do you know is being pressurized, you have not measured the pressure in your airbox, if you do I can bet as much as you want it will not be higher than atmospheric pressure - in order to have positive pressure (which means something higher than atmospheric pressure) you'll need either a turbo, supercharger or if you go by ram air you'd need the airflow (in cfm for example) that is pushed thru your ram intake to be higher than what your engine is cycling - so at a certain speed you need a large enough funnel section facing your direction of travel to create positive displacement, so airspeed x cross sectional area of your intake funnel = cfm with the conversion constants applied and that has to be greater than the cfm into your intake at the time.

the only way I can explain your results if they are real and not placebo is:
1. you have a fuel delivery problem (fuel filter, fuel pressure, plugged injectors, bad MAP or somehow altered MAP readings)
2. when you close "adjust" your aribox you actually get more cold air from under the wheel so that actually mean the air is more dense and therefore more air mass so in fact you add air and not reduce air
3. you did the testing at different outside temperatures

if your cutout above the shock mount is less than 2.5'' i vote for #1, otherwise #2 makes more sense.

#3 - that's for you to answer.

One thing is for sure, without any measurements (at least monitor the MAP output) would be hard to evaluate. If your MAP reading is the same at WOT in both instances, with the little door "adjusted" or open, then your cfm capacity is the same, the difference would be in air temperature which equates in more air mass, if the MAP reading is less with the little door slightly closed then it means indeed you get less air and in that case you might have a lean mixture so you should look at your fuel delivery.

[quicksand]

Well I guess I am getting a funnel affect type ram air. The faster I go the better it works. Remember I have removed my headlight bezels for ambient air as its flow into the air box. So maybe when I am doing 60mph, the air is pressured into the air box. Of course the engine will only ingest what air can pass through the air filter. I know that when I am doing 65mph I can slightly step on the pedal and she will climb to 75 to 80 mph with ease. As far as the hole on the bottom of the box that is for instant air source. And the bottom hole also has a small short funnel. Anyway I do not have any documented measurments but it works for me. I wish you can come take it for a ride. Its like my front flat bumper. I am sure air at 60mph is pushing up against it as a negative affect. Drag. Well just the opposite for my air raming into air box. Eiether way its working. Thanks for your input and any knowledge you have in how all this stuff works, or not. A wise man listens to correction. Thanks for correcting me in anything I have not understood.