About that funny shaped intake tube - there's a reason - Performance!

[avalonandl]

Our intakes were designed to give you a nice quiet cabin, fit within the space, work from -40 to 140 etc........

They will give you decent performance ....oh and they had to build 1-2 million a year....

 

[GreyStone]

Interesting analysis but I also believe it was primarily for sound dampening. As has been noted if this was true then dyno testing should show a loss in power and not gains.

My other question is when this pressure wave bounces back would it not just move toward another cylinder with an open valve instead of ALL the way back into the intake tube? I can see how you might possibly have waves bouncing around inside the manifold but as the cylinders are pulling in air sequentially and consistently the air coming into the tube should be constant and consistent.

If you're talking about a single or two cylinder engine this might make sense but in something like a V8 there's always at least 1 or 2 intake valves open at any given time for air to be drawn into.

Sent from my HTC6545LVW using Tapatalk

I think the stock system may become particularly important when the engine drops to 4 cylinders from AFM - it might help smooth the transition.

 

[avalonandl]

That 8 to 4 cylnder thing causes all kinds of harmonics ...intake and exhaust.....

 

[George B]

That 8 to 4 cylnder thing causes all kinds of harmonics ...intake and exhaust.....

Best thing to do for AFM is shut it off.

 

[Rocket Man]

Best thing to do for AFM is shut it off.

Yep unless you like collapsed lifters to go along with that quiet intake lmao.

 

[Rocket Man]

I think the OP missed the fact that the stock system on our trucks just plain sucks. It’s ugly, huge and it underperforms. It’s been proven for the last 20 years that pretty much any CAI other than the stock one is better. Not as quiet, but better performance wise. I’ll tell you what- when you buy a supercharger ( like I did lol) one of the things they include is a CAI tube to connect to your stock air box and guess what? It doesn’t have a bunch of chambers for waves to “bounce off”. And most of us like to hear our engines at least a little. This reminds me of Harley Davidsons, especially their V-Rods. In stock form they almost sound like sewing machines and the first thing almost everybody does is either mod the stock exhaust or buy an aftermarket one.

 

[GreyStone]

I think the OP missed the fact that the stock system on our trucks just plain sucks. It’s ugly, huge and it underperforms. It’s been proven for the last 20 years that pretty much any CAI other than the stock one is better. Not as quiet, but better performance wise. I’ll tell you what- when you buy a supercharger ( like I did lol) one of the things they include is a CAI tube to connect to your stock air box and guess what? It doesn’t have a bunch of chambers for waves to “bounce off”. And most of us like to hear our engines at least a little. This reminds me of Harley Davidsons, especially their V-Rods. In stock form they almost sound like sewing machines and the first thing almost everybody does is either mod the stock exhaust or buy an aftermarket one.

Glad to hear you have it all figured out Rocket Man - I'll try not to miss any facts in the future that don't conform to your all knowing views of the world.

 

[GreyStone]

That article is way to generic/vague and I'd like to see an infrared, if you will, video of the soundwave bouncing off the backside of the valve, back through the intake manifold, maf, down the tube and into that chamber. Just give me a back to back dyno comparison and db level output to see real world results.

for your inquisitive mind

https://physics.stackexchange.com/q...a-side-branch-intake-resonator-helmholtz-work

 

[Rocket Man]

Glad to hear you have it all figured out Rocket Man - I'll try not to miss any facts in the future that don't conform to your all knowing views of the world.

Thanks, I’d appreciate that! Realistically though, dyno numbers are real, a bunch of words about a generic product don’t prove anything. The article you based your theory on had nothing backing it up test wise, and it didn’t directly state anything about GM’s cold air intake design so if I kept even one person from leaving one of them on their vehicle because they mistakenly thought if they replaced it with something else they would suffer decreased performance then that’s good. I apologize if I offended you, I was just trying to set the record straight. The data doesn’t lie.

 

[avalonandl]

That BLACKBEAR report is interesting but IGNORES sound attenuation. Unless I missed it max dB in the cabin was never measured.

Many soccer moms/dads don't want the loud roar of a CAI.....