I have a K&N CAI on my truck and I believe its actually robbing me of some power in the winter? Stock tune. Seem very sluggish on the low end and other than louder on top end... not much different than stock. Also, pulling my 30' enclosed snowmobile trailer (3100lbs unloaded) last fall when I picked it up it was 70deg and at 65mph I was avg just under 13mpg. Now all I can get 10.5 unloaded and 9 loaded. (All trips reset mpg prior to leaving).

Got a long trip planned in 2 weeks. Do I remove it for the winter and put back in the spring or just remove it and sell it?? Any thoughts?

 

There has been a lot of discussion about how well these CAI work. Some people that have them(and paid big bucks for them)say the performance increased alot and they now can do wheel stands, took 10 sec off their 1/4 mile time and increased their mileage by 10 mpg, etc etc etc. Others say the only thing they do is look pruddy and make a lot of noise. IMHO if you don't have a lot of other engine mods a simple K&N drop in will be just fine. I did a DIY CAI by cutting a 3" hole in the bottom of the air filter box and ran a 3" tube down toward the ground. Cost me less than $20 and it works just fine and increases the air flow(but I still can't do wheel stands).
Jay

 

that CAI isn't really a CAI.. it does, however, provide less resistance to the engines breathing effort..

but anyway:

colder air isn't the gain- but it is.. colder air is denser. denser air is absolutely the gain.. if you could pack a volume of .5 liters air into each cylinder @ 120*f, @ 30*f, you almost have an additional atmosphere- which means you're packing twice the air in as you would be if you were at 120*.. so, you need more fuel to maintain stoich 14.7..

there is a fine line of departure for tunes.. the PCM will maintain stoich until several factors prevent it.. operational temp (coolant), absolute manifold pressure, and air intake temperature all play into the trim game.. the o2 sensors are the tattle tail that the PCM sniffs to make sure it's processing the information correctly.. when these don't mesh (such as when you are running silly low AIT readings), the PCM closes loop and re-samples the data.. you don't necessarily get a code, because it's flashing between open and closed loop while it does what it does.. but what does happen? It fattens up the injector pulse- and you run rich..

it's said perfect air fuel is 14.7:1... perfect for economy is 15.2:1, and perfect for performance is 13.8:1.. I'm gambling a bet here that your perceived loss in power is due to running really rich- like, high 12's to low 13's rich- which will rob you of power.. BUT, on the flip side, you may be running really lean- like, high 15's, low 16's.. that would certainly rob you of power too..

what can be done?

tune for it..

here is what I'm dealing with, just so you know you aren't alone.. I tuned for it, though, and holy moly- having everything loaded to manage the cold air is awesome.. understand, though, this is true ram air, and it is isolated/insulated from the engine bay.. here is a screenshot:




before I worked out the tune, I was weaker than I should have been.. My LTFT were sky high, and 'off the line' low end was horrid.. that little issue is gone now..

so- either tune for it, or live with it.. it won't last too much longer (the winter)..

 

Heres your answer without all the details bells and whistles...
On a stock 4th gen hemi truck, the CAI is a total waste of money.
The 4th gen has the best stock air box, so put the stock air box back in it.

 

without the 'bells and whistles', people simply repeat what they hear and don't know anything other than that..

if a person asks a question, don't you think it would be better if they understood the answer rather than were just given the answer?

 

Sometimes the "bells and whistles" are a little hard to understand without the same technical knowledge you apparently have. Just my .02.
Jay

 

Thanks for all the info. I do understand rich/lean conditions and air/fuel ratios. I really don't think I want to invest the $$ into a programmer to tune for it. The majority of my towing is done on the winter months and the CAI was my hope of a little more power or maybe better mpg. It seems to be reversed in the winter. seems all its doing now is making a ton of noise while I'm towing but not enough to drown out the wife who's complaining that thing is too loud. Think I'm just going back to the factory with my drop in k&n..

 

Well you need to take into consideration that winter blend fuel is already a bit strong, this causes EVERYONE to lose MPG in the winter.

 

Whatever gives you more peace and quite, whatever the source of the noise, will make your trip more pleasureable. I know this for a fact!!!!!
Jay

 

Most average people really dont care about details... sometimes less is more