I have a 2004 FX4 and i want to put a CAI on it. Problem is im having trouble deciding on which one. My local big brand said out the door for the 3.5 AF1 would be 370 installed. But i thought that the 3.5 would run my engine too lean. so im asking will itg cause my engine harm?
Thsnkd

 

Running a AF1 3.5 would possibly cause your engine light to come on because your running to lean. You need a programmer. I think you could use a 3.25 AF1 and be ok without a programmer. Call troyer perf and get their opinion

 

I've read it will cause it to run lean until you get a programmer.

I personally like the S&B intake which is 269 and installation is very simple. S&B puts out very clear directions.

 

AF1 is so much better than S&B. The 3.5" will cause you to run lean if you do not have a tune. You are better of getting the 3" if you dont plan on gettin a tune anytime soon.

 

Please explain why the AF1 is so much better than S&B

 

for one it looks 100X better. and dyno graphs have proven that it out performs other intakes

 

I would like to see the Dyno charts with that info, as I am trying to start selling AF1 intakes, would be good to have that information. I am always weary of dyno #'s unless it is being tested on the same truck, the same day, same dyno, same everything.

Also, AF1 uses the S&B filter, so I wonder how they can get much higher numbers than S&B is getting.

As far as which one looks better? I guess thats up to the customer... I really like the S&B box with the clear lid, but the polished tube is pretty slick.

 

dont get me wrong. s&b intakes are great. i just prefer AF1. ill try to get those graphs. Im pretty sure mike troyer tested them. and i think the higher numbers on the AF1 has to do with it being an open element. instead of closed like the s&B

 

Thanks for all the input guys

 

keep in mind that an extra 1-2 horsepower is not always a reason to take one intake over another. What about coverage? warranty? reliability? All things to consider. AF1 and S&B both make excellent kits, either one will make you very satisfied.

 

AGREED!

both kits are great quality. I like the S&B because of the airbox...will keep water/dirt out when offroading better than a an open filter element... but someone who keeps the truck on the street may do better with the open element

 

Actually the reason the AF 1 out performs the others including the S&B is the cross sectional area where the mass air sensor is located is much larger than the others. The af 1 is a true round tube from end to end, whereas the others flatten out into an oval shape restricting flow. The manufactures do this so their CAI's won't throw a code, but the downside is any cai that doesn't throw a code doesn't flow much more (if any) than stock, so basically they are just eye candy.

The AF 1 in the 3" size is just barely within the parameters of the stock programming (some 04's still needed a tune even with the 3"). The 3.25 and 3.5" sizes are beyond the limits of the stock tune and require a custom tune so they will not throw a code.

 

If you still take your truck to the dealership for upkeep, your going to want to have an alternate 3" tube if you go with the AF1 3.5". (or reinstall your stock intake) Reason being, you're not going to want to bring your truck to the dealership with your custom tune in there, therefore you're going to probably put your stock tune in there for the maintenance. If you leave the 3.5" tube on there, it's going to run lean. I'm no expert so I don't know what kind of engine damage would result from that for a short drive to the dealership but why risk it.
Something to think of if your trying to keep things practical and versatile.

Question: If using the 3.5" tube with a tune to fix the air/fuel ratio, (Increasing fuel to the mix) would that cause your MPG to go down? I would think yes, but if someone with some more experience could chime in, I'd appreciate it. Thanks

 

I have the AF 1 in the 3.5 size and my truck been back to the dealer a couple times with it on and the custom tune loaded. I just tell them to leave it alone, and they do. I even told not to do a recall that would require a PCM reflash and they didn't touch it.

As for the tuning for a 3.5, they do not change the A/F, the mass air transfer function is what gets changed. Basically it rewrites the data table so the ECM sees the correct amount of incoming air. Without the changes, the MAF reports a larger amount than the ECM can tolerate, and therefor throws a lean code. On the other hand, amature (sp) tuners and the edge bump up the fuel to compensate and that will decrease fuel mileage.