Intake tube length and engine performance?

[KidVermicious]

I'm getting ready to do something about the stock intake on my 22RE. It runs from the throttle body on the passenger side across the front of the engine bay to the airbox on the front drivers corner.

A common mod on these motors is to swap the airbox and battery, which has the effect of drastically shortening that intake tube length, and guys claim to get a performance increase out of that. I'm not sure I buy it though, because I've always understood a longer intake tube to mean a smoother intake charge and a greater reserve on the engine side of the AFM to use when you punch the throttle. I'm betting any performance increase comes from isolating the tube away from engine heat, leading to a slightly colder intake charge. I know some of you guys have a better grasp on engine theory than I do, so input is welcome - am I right?

Anyway, here's the options I'm considering:

• leave the stock black plastic tube in the stock location
• wrap the stock intake tube in insulation tape
• replace the stock intake tube with stainless tubing and insulate it
• relocate the intake , shortening the tube

Thoughts?

 

[aha2988]

just in my small amount of experience I can agree with you on the idea that it ins't how long the tube is but more so how well it can, and where it does pull air from.

I have a snorkel tube that runs out of the factory box through the fender into the cab. I didn't loose nor gain any performance with the extension of the intake as well I haven't heard of external snorkels hindering performance either.

 

[BucknutBob]

Some snorkels have been shown to actually increase power, due to their ram effect, smooth bends, and the much cooler air they're drawing from. It's not necessarily about how short the tube is as much as how smooth the flow is, and as mentioned, how far from the heat the filter/inlet is. No matter what, though, you're not going to gain more than a handful of HP, if that. Just like with tires/lifts/gearing, a modified intake is only one part of a complete puzzle if you want to see proper gains.

 

[hurt4x]

I always thought a longer intake path after the TB generally increased torque and shorter after the TB generally helps top end performance. (ex. 5.0 truck intake Vs. 5.0 mustang intake) not really sure about before the TB though.
I cant see any very noticeable changes coming from shortening or lengthening before TB.

 

[KidVermicious]

I always thought a longer intake path after the TB generally increased torque and shorter after the TB generally helps top end performance. (ex. 5.0 truck intake Vs. 5.0 mustang intake) not really sure about before the TB though.
I cant see any very noticeable changes coming from shortening or lengthening before TB.

From what I've read, you need significant changes in length after the TB to really alter your curve - like, feet of change. Which is why throttle body spacers don't work. Or so The Internet says.

Good to hear I'm not off my rocker on the intake length before the TB though, thanks guys!