CAI, interesting

[Jonn]

I have a 91 Lumina with the 2.5. Long time ago it had problems from neglect, had to replace about all the sensors in it. At same time i made a cold air intake for it, well its ran "ok" since the sensors were all replaced not not perfect, always had a lag in pickup when trying to accelerate on the hiway, tried everything under the sun but still always did it.
Well, i finally got tired of hearing the air sucking in that intake and put all the original back on including the original filter, and guess what, the lag is gone, fuel milage has seemed to increased a tad, and pulling power up hills at any rpm is smoother and comes in with less throttle. So all i can figure is the total free air intake made the air move to slow?
Any idea's?

[Jim Adams]

John when you made your cold air intake did you make a spot for your cold air charge sensor or did you leave this unplugged?

[tblake]

how about routing? most people just buy the cone filters and slap them on with a piece of pipe. That is all great, but it isnt sucking in cold air by any means. Did your homade CAI restrict airflow? Just a thought.

[Jonn]

Originally Posted by tblake

how about routing? most people just buy the cone filters and slap them on with a piece of pipe. That is all great, but it isnt sucking in cold air by any means. Did your homade CAI restrict airflow? Just a thought.

My sensor is located in the intake, the actual alum. intake, ther eisnt one in the piping on a 2.5

I used the original hose, about 3 1/2 inches? put a short connector in it to add additional hose of same type, ran it down to very bottom of the cars frame below battery, and made a metal shield that covered the engine side of filter (not against filter) basicly it was sucking air from under the car, also shield extended down about 2 inches below filter on back side which also im sure, added a slight "scoop" effect.
I dont know why it acted that way, but only thing that has changed it make it run proper was putting original box and filter back on, and as for fuel mileage, well evey day i make two trips to same location, it always used 1/4 tank for the 2 trips, now it is averaging just a little over half that, quite a improvement actually. Throtte response is way better, and seat of the pants , light to mid throttle up hills is way better too. I have no clue but going to leave it this way and hope it stays. Now i am wondering about modifying the air intake on the Z24 i just got with a 3.1
It has cowl induction thru the hood (2 layer fiberglass hood with air gap bewteen layers) just FYI if ya didnt know. Oh well, i have saw weirder things than this...

[tblake]

if you want to search around the forums and look for one called "tornado" Jeffcoslacker when very deep into this issue of how the incorrect routing of CAI's in cars these days can actaully cause a vacuum effect because of the aerodynamics of a car. You should read it, its quite interesting.

[Jonn]

Originally Posted by tblake

if you want to search around the forums and look for one called "tornado" Jeffcoslacker when very deep into this issue of how the incorrect routing of CAI's in cars these days can actaully cause a vacuum effect because of the aerodynamics of a car. You should read it, its quite interesting.

Yeah, i have thought of a vac effect, but that doesnt really fit as it would do this at speeds to slow for that to have any effect really. That filter was pointed toward the front of the car say at about a 45 degree angle, back/bottom side had a shield toward engine, shield wrapped around under filter toward front of car, and formed into what would look like a upside down hood scoop with a filter on top. But, i will read what you suggested anyway, cant hurt. LOL just happy now its working better

[tblake]

hey, just a side note, I just knocked 3 holes in the bottom of my stock intake air box, and put it all back to gether with a k$n panel air filter, and the think sounds like a V8 when I mash the gas. It was better pick up, and higher low end torque. I'll let you know how my gas milage is now. Last time I checked it, I pulled off 22.9 miles to gallon with the AC on most of them time. SO yeah. Just to let everyone know.

[NeonKnight]

i just took off my CAI pipe and K&N Cone filter, i started noticing really crappy low end and pickup. I did notice that the sound was nicer but if i cant have my low end screw it.

[Jonn]

Originally Posted by NeonKnight

i just took off my CAI pipe and K&N Cone filter, i started noticing really crappy low end and pickup. I did notice that the sound was nicer but if i cant have my low end screw it.

Yes, so many like the sound, i have nothing against those who do, it just isnt my thing, i like the sound on my Z24 V6,but it is quiet unless you have your foot in it, just dont care for it on this 2.5 Lumina. I also have a large convertor and a large muffler both from a V8 car on it so i can keep exaust quiet without restricting it. V6's arent too bad, but give me a rumble of a nicely tuned V8 any day. To each his own i guess.
I average 24 to 26 mpg on the 2.5 Lumina with mixed driving, not bad actually for a 91 just about to turn over 200k. Burns no oil, no leaks, Original auto tranny as well. Cant complain too much

[tblake]

no, just to clarify, by knocking those 3 hols in my intake box, I did increase my lower end torque. My car even seems quieter at idle because it can idle down lower, and it sounds more beefy under hard acceleration. I have noticed better throttle responce also.