My mechanic friend gave me his opinion today of cold air intakes. He has worked on all types of cars and trucks for over thirty years. He feels in theory they should work, if cold air is "rammed" into the box. He thinks replacing the oem filter with a high quality replacement is a quick, cheap way of getting almost the same result as a cai. What do you think? I'm confused.

 

The pluming is less restrictive than a stock system there for allowing more air to move freely

 

What do you mean by less restrictive?

 

The tube is just a round tube with as few bends as possible it dont flatten and has no little useless tube thinghanging down.

 

The also dont have that accordion looking thing right after the MAF. I have the airaid JR which is the best of both worlds. A free flowing tube with a replacement high flow filter. I think they are worth the money espically in the summer when the air is hotter.

 

Definitely have to say they are worth it. I saw at least 2-4 MPG gas mileage gains in my truck Not to mention the horse power gains ( DYNO says 8.1 HP gains!!!!) Therefore I have to say that it is not hype and that it actually does increase power, efficiency, and lastly the esthetics of the engine compartment as well!

 

Well a K&N air filter alone will not give you the same performance as a CAI. But a larger air intake tube along with a K&N air filter (or something close to that) will get about the same result.

K&N = More Air
Tube = Smoother Airflow
CAI = More Air and Smoother Airflow

Some CAIs can flow more than others, but be fair warned, you will not get 100% of the performance out of a CAI or most bolt on mods without a tune or a detailed programmer.

No tune/program needed:
1. K&N or other high-flow filer
2. Exhaust
3. Intake tube
4. Any combination of the three.

Tune/program needed:
1. CAI - Most will need this to get the performance, but not all of them.
2. Aftermarket MAF
3. TBS especially when used with a CAI
4. Headers, Cam, Heads, etc...

(NOT ACTUAL FIGURES)
If your stock filter flows 100 CFM, then a K&N would flow 180, but it would be kicked down to 150 when flowing through the stock tube. So you replace the tube, now you get the full 180 CFM. Engine will handle up to 200 CFM on a stock tune lets say. Gain would be 4 hp. Now you tune it, the engine now knows that it will be getting 180 cfm consistantly so it can add more fuel (Power Enrichment). The engine now uses the additional air more efficiently by keeping the fuel/air mix closer to the ideal ratio. This bumps up the power 6 hp instead of 4.

Now you get a CAI that flows 220 CFM but you don't have a tune. Remember that the engine can only handle 200, so the extra 20 cfm causes the fuel mixture to lean out, the engine sees this as a problem and backs the timing up to compensate. Now its a 5 hp gain when it should be a 6 or 7. So you tune the truck, the engine now knows that it will be getting 220 cfm consistantly so it can add more fuel (Power Enrichment). The engine now uses the additional air more efficiently by keeping the fuel/air mix closer to the ideal ratio. The extra 20 CFM might even allow for timing advance so the engine can squeeze out 1-2 more hp.

Examples: (Hypothetical gain on just the intake setup alone)
K&N = +3
K&N and tube = +4
K&N with tune = +4
K&N and tube with tune = +6
Average to Large CAI with tune = +7-8
CAI wihtout tune = +5

Additional modifications have the same effect. TBS will require a slightly different injector slope as it will modify the powerband of the engine. Exhaust alone will cause greater efficiency at higher rpms, but a tune can bump up that power gain and increase torque which can be lost due to the reduced backpressure.

Whew, ok now I have to get back to work. Lol.

 

wow... that had to be one of the most detailed explanations i've read on this forum.

 

Wow

 

You know you are in the wrong profession when you can't explain a program you wrote but can explain why the bosses VW pings after his son put an intake on it. Lol.

That explaination might be off a little but I researched it online and experimented with my truck and that is the conclusion I came to.