i have the factory style filter. i am not using the foam pre-filter, b/c when i tried it, it sucked down my filter minder & throttle response was down as well. took the foam out and all better.

i am the opposite of you. the only time i hear mine is on acceleration. once i hit 1500-1700 rpm it starts to really whistle, once i get to ~2500rpm it turns into more of a whine than a whistle. when my torque converter locks and the rpms drop it really whines. not sure why. seems like the more i drive the more i hear turbo come to life.

like i said before i don't have my boost gauge hooked up so i don't know what i am boosting right now, but before i could only max out at 6 psi. i doubt this intake mod has gotten me another 5psi, so i am really looking forward to what it sounds like when i can get up to 10psi.

 

My truck seems to like to amass leaves in the cowl, so drainage would be a concern for me, and i dont want an air filter full of em either. Also, when it snows and there is 4" of snow on the cowl, idk how high the pressure is then lol
I know the cowl is high pressure, im just saying how is it more pressure than the grille? Not a scientist here but logic of aerodynamics says the even though the cowl is a positve pressure zone, the grille is still going to have more pressure. My factory 'air tube' goes through a hole in the core support. I guess is what im saying i dont see the advantage of cutting a hole in the cowl, when it seems like going through the core support has more air, and less chance of foreign junk in the air cleaner. Unless you just want to hear the turbo louder all the time.

 

K&N air filter, people give them crap for the new gen filters being nearly as efficient it doesn't justify it. But on the old ring filters, it makes a WORLD of difference. With the addition of the filter (and straight pipe), my truck has a lot more get up and go, I'm generally speeding by the time I hit half way down the block from a full stop, vs still trying to gain speed. With a turbo I think this truck would get me killed.

I see it as a less work upgrade. Doing it in the front is a more labour consuming upgrade IMO. I don't know what it's like there. I see the front air intake would cause more problems than cowl, especially where I live with heavy rains and snows. It hits the front of my truck much much more than where the cowl induction would (also leaves and crap seem to aim there). Being heavier than the air, it would either go past it more often than not. I'm not an engineer, but it was something I observed last winter contemplating this upgrade. Though in a more temperate climate it wouldn't really matter.

 

double post.

 

that is true. other than figuring out exactly what i wanted to do it took not time at all to install and get on the road.

 

the grill is not a high pressure area.

some high pressure area's are;
up high on the hood,just as the air is forced to push up and over the truck (where the stock intake is on 92-97 9th gen trucks.)
the cowl.
the inner wheel wells (but she'd need to be a pavement towing queen only to attempt this location.)

don't be confused between max air flow,and high pressure.the difference is pretty great,unless your going well over 100 mph or so,then i guess they even out.

rain,nor snow enters your ducting by doing this mod.i know it seems hard for many to believe,and im not sure why lol,but it is so.
mine remains hooked up to the cowl year round,and inspected regularly (yes even when plowing snow in the middle of a nor'easter......the results = high and dry.)

 

hmm im thinkin i need to do some "testing" with out the foam pre filter!!

 

water report:

it rained all night last night and i drove threw some pretty good rain coming to school this morning and everything was bone dry in my air box and intake tube

 

you should try posting a video id like to hear it from inside the cab if possible

 

I will to get one monday. the growl inside the cab is noticably more over the factory intake tube. the whistle seems to be getting more noticable, but you still have to have the radio off to have a chance at hearing it.

a couple weeks ago i filled up both tanks. i used about a tank and a half while using the new cowl intake. yesterday i calculated my mpg and i got 18.8. i figure i can hit at least 19mpg on my next to tanks all on the cowl intake. i was not babying the thing either. gotta hear that whistle right? LOL!

 

what kind of mpg's where you getting prior to the cowl intake?
i had a bad rear axle hop issue while i was doing all kinds of these mods,e-fans/cowl intake etc and didn't get to see what they did as i was going along.

 

before cowl i was getting 17.5-18.0mpg. that was driving in a fairly spirited manner. my new mpg with the cowl was also in a spirited manner.

 

well i removed my foam pre filter and its slightly more noticeable but nothing like i was hoping. who is not using a foam prefilter. does it matter that you dont use it?

 

There's a foam pre-filter?

 

I pulled mine off a while back. Got tired of blowing dirt out of it with compressed air all the time, haven't noticed any difference.