'98 Air Box Cut or Not

[A Wise Guy]

I'm undecided if it will be worth opening up my air box or not. I've read other threads about it but after looking at the way it is set up I'm not sure if it would be a worth while mod. Right now there is an unrestricted tube comming in from behind the passenger side headlight bringing in cool air. If I open up the air box it will let more air in but it will be air from the engine compartment which is warmer. What do you guys think?

 

[dennab]

I'm suprised no one answered this post, but no one did, so i will.

Seems that most guys here run an open filter, which dyno testing on other vehicles proves that is worse than a k&n in a box. I've yet to see the dyno on explorer, but all the hot air cannot be good.
So i don't have an open filter.

On the downside, that hole behind the light, i don't think is enough. So what i did was take an extension from one of those big shop vacs (you know what i mean). And cut about 4 inches from the bigger end. I cut a round cutout right next to the one that goes behind the light. and then in the plastic plate behind the light. Then i glued the pipe from the vac in the hole. making 2 holes entering the box, instead of one. Keeping both with fresh air, and increasing the amount of air able to enter the box.

I know for a fact, when you put an open k&n air filter in a 5.0 mustang you lose 2-3 hp over putting a k&n in the stock box. So i figured letting more air in the xplorer box would even it up.

 

[A Wise Guy]

Thanks much. Any one else?

 

[Hokie]

I don't think I agree with dennab... given, you might lose a little power on the dyno b/c your truck is sitting in a garage somewhere and all of the engine heat is being sucked into the air fitler, according to KKM's tests (website) at driving speeds, the temperature at the intake is only a few degrees higher than outside. This is why KKM classifys theirs as a air intake as opposed to a cold air intake. But i can't believe that I would lose power... especially when you compare the horribly restrictive stock box to the open cone of the KKM.

 

[Bottomlesspit]

Also...that unrestrictive tube you mention, the air intake snorkel, is actually pretty small. It does bring in "cold" air from in front of the engine bay, but the volume is not all that great.
As for my mustang on the dyno...yeah, sitting still was not all that great, but...the hood was open too, so the under hood temps were not all that great. The open filter was exposed to cooler air coming in from the top.
I do think the filter box mod is good...if done right. I removed the snorkel tube, drilled the holes in the box, but did not drill holes on the back side towards the engine. I kept the holes in the bottom and front sides of the box. My box is still getting most of its air from the front side where the snorkel was.
As you said, hot air is less dense and not good, but the restricted air inlet is not good either. I think the holy box is a good compromise...if done right. An open filter can be used with great effect (just look at the Ford Lightning pickups) but in not necessary in out case with out limited power.
I have not seen dyno results on an Explorer either, so I can't compare.
I did dyno my stang with a large, open K&N filter...and again with a fender mounted cold air setup. I got results within 2 hp of each other every time.
Ken

 

[98svt]

i have a 98 5.0 and cut the whole front of the box out and it made a BIG diferance at half to part throttle....i cant tell you for fact that it will make x amount of power more than factory but it did make it a worth while mod....this was when the truck was stock and new...it has all been changed since but, before, it was a good thing to do and it did make a diferance....good luck

 

[A Wise Guy]

98 SVT did you also remove the plastic flap from behind the headlight opening or not?

 

[98svt]

im not sure what you are talking about as far as the flap is concerned but when i had the stock air box in it i just took out the bottom half of the box and cut ( with a dremel cutting tool)...the front of the box where the inlet tube was....i just cut the whole front of the box out but i left enough for the filter to seal the top of it of course and it DID make a differance at half to full throttle....i dont really notice much of a differance at just normal take off but flooring it or 1/2 to 3/4 throttle take offs it made a good bit faster....so good luck...

 

[5literx]

I totally agree, with the guys that leave the box, and modify it. open filters are overrated. with extra flow added to the bottom, towards the front or fender, i do think that's better than a filter sucking in air from inside the engine bay.

Hokie, keep in mind on the dyno the car is not moving, but there is a fan (maybe it's not much) but the hood is open. The hood is not open on the street obviously.

 

[98svt]

my opinion about the open filter verse the air box it this....open filter WILL bring in more air than a air box.....but the engine in these trucks, unless heavily modified, does not need as much air as the open filter can produce....if you have a stock engine with just a few modifications such as chip and ehaust , then you will be better off saving your money on the iar intake w/open filters.....on the other hand if you have or soon will have a heavily modified engine such as cam, bigger upper and lower intake, more compression, ect then you will benifit more from an open filter than a air box....as far as the heat ratio of air box verse open filter....you WILL get more "hot" air from a open filter than a airbox but youll get more air period than a air box.... so its a catch 22.....for very modified engine go with open filter....for stock engine with minor mods go with a cut air box and youll be better off.....this is just my opinion and comes from my experiance over the years.....good luck to all with your x's....

 

[A Wise Guy]

Originally posted by 98svt
im not sure what you are talking about as far as the flap is concerned but when i had the stock air box in it i just took out the bottom half of the box and cut ( with a dremel cutting tool)...the front of the box where the inlet tube was....i just cut the whole front of the box out but i left enough for the filter to seal the top of it of course and it DID make a differance at half to full throttle....i dont really notice much of a differance at just normal take off but flooring it or 1/2 to 3/4 throttle take offs it made a good bit faster....so good luck...

The flap I'm asking about is mounted to the radiator support behind the right headlight and in front of the air box. It has an oval hole in it for the air tube to pass through it. If you were to remove the air box and the flap you would have open access to the wiring that plugs onto the headlight bulb. Hope this helps.

 

[98svt]

ok im sorry i know what u mean now....but no i didnt take it off for the intake air but it did break off so its not there anymore....i honestly dont think it will make a differance so you can take it off or leave it on whatever u preffer....try both ways to see which is better....good luck