I e-mailed Dave from Pro Cold about why they are using the OEM intake tube with it's baffles & resonators and here's his answer.

"The reason we as some other intake companies have decided to use the stock or stock type intake tube with an air muffler is that we actually got less HP from a straight tube.

The intake tubes with air mufflers help correct turbulences and also aid in having some extra air available so when you go to WOT or gas it a bit it is more responsive because it has some back up air.

We could have made our product with a nice anodized piece to make it look really cool but “form follows function” around here and we just wanted to make power the best way possible."

Now this makes sense to me and AirAid has told me the same thing. Some may still disagree but I for one am satisfied with his answer.
Jim

 

Sounds reasonable enough.

 

makes since but i still dont believe they LOST performance thru a straight tube...and those extra baffles are there to quite the intake down and to provide extra air..I just dont see how the stick carries more velocity then a UPD tube

 

Not a flame, but it is possible that the GM engineers put more than sound concerns and tip in air supply into the equation for the air intake tube. It is quite possible that it is a tuned tube and the resonation through that tube actually smoothes the airflow instead of causing laminar shearing of the fluid through a smooth pipe. (yep, I said fluid in reference to the airflow, chew on that)

 

Same thing AirRaid told me a few years back. Hmmm....Airraid makes their own tubes now though.

 

i think all of this is done on stock vehicles, modded vehicles would be different and would benefit from a smooth tube..

heck thats like saying, why port heads, leave all those extra restrictions in there..

 

It's funny you would say that. When AirAid came out with their MIT tubes, I e-mailed them and asked if they had dynoed them and how much HP did it make over the OEM tube on a GM 5.3L engine. The tech who answered my e-mail said it didn't make any more HP than the stock tube. I e-mailed him back and asked why they were making it then and his response was "because some people don't like the looks of the stock tubes and want something different". He did say that the tubes did work better than the OEM tubes on the FORD trucks but not on the new GM trucks. I thought that was a pretty honest answer! I don't know if the OEM tube is better than a smooth tube, or the other way around. I'm just passing on what I've been told to inform other members. You guys know me and my tinkering, I will probably find a smooth tube that will line up properly and try it, I like to tinker. I will say this, when I was using the stock tube on my home made ram-air a long while back, my truck didn't seem to pull better in the high end with a when I added a smooth tube but did seem to lose a little on the low end. So, for driving around town day to day, the OEM tube may be better. If you're going to the track or a night of hot rodding, put on the smooth tube. If anyone has a Volant tube just sitting around, let me have it (for cheap) and I'll do a comparison.
Jim

 

ok, interesting BUT....when i went from stock intake to a UPD i got a TONNNNNN of throttle response from it, and now i'm back to a volant box with a stock tube and the throttle response is back to zip like it was before. so i had better response and power with the strait tube. maybe it's a case by case basis type thing, and weather and climate could have some play in it also.??????????????/ who knows.