Ive heard they help with gas mileage and horsepower. I have also heard that they are a waste of money and dont do anything?

Im thinking of getting one but i want to make sure its worth it first.

 

Bottom line:

Physics states that cooler air has more O2 molecules volume wise than warmer air. If you build a cold air intake CORRECTLY, with a heat shield and direct source of cool air, then yes, your will have better results. However, do not expect a giant kick in the pants with horsepower and sudden Hybrid-like MPG's. With a good CAI, you might gain maybe 3-5 hp and 2-3 mpg. Now, if you get a better flowing exhaust with a CAI as well as a bored TB and maybe some Neon injectors, then you're talkin more noticable kick in the pants HP and slightly more MPG.

 

All of them ive seen have little if any HP gain. Most of them arent protected from water and debris. stick with the stock box. if it aint broke dont fix it.

 

Cold air intakes are just cold cash intakes for the companies who make them, don't waste your money.
Just get a K&N drop in.

 

I would rather spend my cash on other valuable jeep parts than getting a cold air intake...

 

thanks for the replies. i think i will spend my money on new tires and a roof rack before i buy a cold air intake system.

 

dont buy a CAI if u ever decied to go wheeling in mud its gonna suck a lot of water and mud get a snorkel kit cold air and water proof

 

...and they look BADA$$!
x2 on exhaust. Pretty much nothing you do will amount to much with out free-flowing exhaust.

 

snorkel is a "cold air intake"

 

I probably shoulda mentioned CAI's and off-roading in my original post. If your XJ is a DD and never sees mud, then as long as you're going to upgrade exhaust and all, build your own. I built a CAI for my XJ to go with my new APN header, free-flow cat, and turbo muffler, and I noticed a bit of change (I utilized my stock airbox as a heat shield/ debris shield). If you off-road, then either get a snorkel, or relocate your CAI somewhere higher in the engine bay, or like said just keep the stock airbox and maybe cut the restriction in the center.

 

My friend just bought a garrett turbo with a large electric motor attached to it from ebay. I was a instant skeptic, he paid $350 for it from a place on ebay that builds them. It uses a throttle switch for 3/4 to full throttle, it actually works well. It gets 5psi and the pulls a lot harder (99 tj) I'm gonna do the same next pay day. I will do my first thread.

 

Cause "air" is more dense at a lower tempurature, but the nitrogen(70% of air) and O2, have Ionic bonds, therefore it will take pressure above atmospheric(about 14 psi) to actually get a denser gas product, or a range of +/-200*C. CAI's are a waste of money.

You got your CAI, all hyped up, throw it on and take it for a drive, its pulling air from farther away from the engine and its immense heat, down the intake tube and into your throttle body, SWEET more cold air.......whoa wait a minute there buddy, its not instantaneously allowed in the intake valves, damnit, it just heated up to what it would have been with the OE intake box. BUT its still mildly colder, right? Yes, but minimally. So Im still getting HP gains? Yes, minimally.....but when are you going to let those horses roar? I mean peak hp is rarely ever acheived at normal driving speeds, damnit.

Peak torque is at 5500 RPM, peak horsepower is at 6500 RPM for almost every modern engine. Horsepower is responsible for moving the vehicle along and gives it the ability to cruise on the highway and accelerate in normal high speed driving conditions. Torque is the force that helps the vehicle start moving from a stop and pulls it up steep hills. Torque steps in again to provide power when your accelerating hard, hauling items or towing something behind the vehicle.

Now, a CAI is expected to give you 3-5hp.....added to your BHP, mind you no one cares about BHP, whats your WHP gains? Roughly around .67......hp gain. Totally worth $200.

 

Don't know about all XJs but OBD-II models have a "intake air temp" sensor which sends intake air temp info to the ECM. The ScanGauge (any scan tool I guess) will display the intake air temp reading from the ECM. Cruising down the highway, intake air temp and ambient temp are almost the same on the XJ and yes intake air temp rises some when vehicle speed is reduced (less cool air circulation). I think the stock CAI works pretty damn good and IMHO, any intake that has metal components (ie., shiny chrome) is a HAI (hot air intake).

 

Never did any research with the OBD2 models and the intake air temp sensor.

Agreed, The metal will conduct the engine heat phenomenally.

 

I agree with you on the K&N. Have them installed on my Wrangler and F250 and plan on adding one on my Cherokee. Yes, slight increase in air flow, but the reusable part is worth the money.