Re: Changed my air box
 

:o I used a section of dryer duct to solve the collapsing issue, maybe I got some smoother air flow in the deal. It was a cheap backyard fix. If you have some patience you just buy one section of 6" duct if I remember right and cut it to length first. Then you join the seam, then you squash it to an oval shape so it fits inside the OE duct. That's the part that takes time & patience to get the fit just right so as not to loose too much flow. As a "insurance" policy against future collapse of the metal duct I took a framing joinery flat plate, that was large enough so that after I bent two opposing right angles, and used that to support the final oval shape. I screwed it in place driving the screws in from the outside of the duct. I used standard peanut framing screws for that as they're only 7/16" long. I have had that in the car since 05 and it seems to work great!

Like I said it will take some time to get the oval just the right volume & shape as when I was done shaping it I used wire-Eze to get it inside the OE duct. LOL I should have waited for the guys Dom used to come up with theirs, it would have saved me the time! LOL

:cheers:
Tom

Re: Changed my air box
 

I didn't realize the "Claw" retained use of the accordion tube. Too bad - a missed opportunity, methinks.

Yes, the accordion, otherwise unsupported, will likely collapse at WOT even if attached (in my case) to an open K&N filter box.

I learned on this site that collapsing was an issue with the hose, and it occured at around 5500 rpm or so. That too was my case: fell flat on it's nose at 5500 rpm.

Killing two birds w/ one rock, or sleeve, as it were, I used a strip of 16ga aluminum cut approx. as wide as the tube is long and approx a foot or a little more long and shaped it into an oval to fit snuggly on the inside of the hose. I trimmed the lenght to overlap enough so I could pop-rivit the seam. Works like a dream, and I knew it the first time I went WOT and it pulled hard to 7000+ rpm.

Not wishing to beat a dead horse, but some go to all the trouble of routing out the inside of the air horn at the same time the TB is opened up to 63mm or so and not address the accordion hose seems counter productive (to me). Certainly the TB effort works - well known fact, and maybe porting the air horn helps too. But, I have an idea that to go to that extent and NOT address the flow across that accordion bridge piece can't be as affective as it would be if it was smoothed out. And, when I look at the C5 and C6 filtered air intake tubes - i.e., smooth - it seems like that issue was finally taken into account.

Dyno time is expensive, no question. And, dyno time is further increased when there is any significant increase in output resulting from a physical change, as the tune may need to be tweaked to be keep everything in balance after the change. However, it would be interesting to test this and other ideas to see what is valid and if so by how much. It gives me an idea for possibly a funded dyno session setup for the purpose of exploring this and other power adder ideas. After all, the Registry helps sponsor certain social events, why not a a "tech" event that consists of a specific, formal set of experiments in order to quantify validity? Just a though.

P.

Re: Changed my air box
 

I don't doubt a smooth duct = smoother air flow. The question is: Is there any noticeable change in engine operation or performance between the ribbed vs. smooth duct? Not so sure you could really acurately prove it. Maybe a "tech " event is the way to find out. We need to get a list of things to test, then find a shop to rent for the day, and get enough people to split costs and test different theories. I would be into doing that, I would test air boxes, ducts, and coil packs. I'm looking into Marc's hoops to prevent the collapsing issue (even though this hasn't happened yet). :cheers: