During September I finally took out the short ram out of the 4th gen and got a CAI setup. Cold weather is approaching here fast in NY, so after being curious and doing some research on other forums.. What is your thought on it? We all know cold air = better for engine performance. Operating temp may take a little longer to reach, but what about when it's 30* outside? Crazy talk here, but is there such thing as too cold for the engine? Not so worried about hydrolocking from snow or rain but more of it not being so efficient. Will it cause a tad more lean mixture? MPG drop?

 

Really cold air is not good for the engine because it does not allow for the gas to vaporize in the air going to the cylinders. This is immaterial to having a CAI or the stock air filter setup.

The car/engine manufacturers have known this for years and years. What they have done is to heat the air that goes into the engine. This is done at the throttle body, which is after any kind of air intake/filter system you have. In the Maxima, the heating is done by engine coolant. Of course when you first start the car, you won't have this heating, but since the coolant comes from the cylinder head, it will get warm coolant as soon as possible.

Until the engine sends warm coolant to the throttle body, the ECU (which gets a coolant temperature reading from the ECTS) will cause the fuel injectors to spray in a rich fuel mixture so that the engine doesn't run lean.

 

I figured it would run lean because of the air being so dense. I guess I'll take off the pipe for now. I was aware of the engine bay becoming warm and the piping can get somewhat hot but I guess winter makes that twice as hard to achieve. Cold air into a cold engine doesn't seem like a good idea in the first place (common sense). I did not know the throttle body received coolant.

 

Coolant by passes for the throttle body are somewhat common on these cars, especially with the NWP spacer kit. I have never heard of anyone having problems in the cold with a bypass, so I doubt a CAI is going to cause you any problems. The piping in the bay is still going to get warm, and if you warm the car up long enough before you drive, unless it's super cold, I doubt you'll have any problems. Often times, the cold weather has some nice benefits in naturally cooling the motor in the winter, and lowers my air intake temperature by a fair amount, but nothing near too cold for comfort.

 

I guess I'll give it a shot lol! If I have to take it off it's not a pain to do.

 

Had the same motor as you for 8 years now, don't put A CAI on it in the winter unless you wanna lose acceleration, keep it stock in the summer and SRI when temps go below 60s....just put my SRI back on this weekend now that its getting cool...love the sound and that extra few ponies felt.

 

Back in September I finally got the ebay pipe for it because I originally had the SRI setup. Wow, what a difference it was and it sounded nice!