Prior to my roundtrip journey back home to Maine this past weekend, I paid another visit to Home Depot to buy supplies which I felt would make this PRM intake of mine even better. Before I forget, I averaged 29.4 mpg on the 9-hr one-way journey (going about 70-75 mph for most of the trip). I didn't go beyond 6K the entire way down so consequently, I believe the intake in its stock form, may have been responsible for 2-3 mpg improvement over stock. FWIW, on the way home, it dropped to 24.5 mpg but that's because of the incredible fun I was having enjoying the fruits of my Yankee ingenuity with the intake modifying.
First off, I wanted a direct feed of cooler air from the wheel well to the filter horn section, increasing the venturi effect which is the principal focus of the PRM design. I got a few sections of hard plastic plumbing, connected them appropriately and fished the section down into the wheel well, just above the main hole leading down into the bumper area. There is really only about five inches of white plumbing pipe extending beneath the section where I tied everything to the hood latch extension. In fact, I was lucky and bought just enough pieces for a perfect fit. I had to play around with the curvature of the section entering the horn area but it worked great. It's solid, doesn't move at all and just for grins, I wrapped the piping just to the left of the horn section with Rubatex (sp-?) insulation. Boy, does this stuff work like a charm.
Anyways....I replaced the insulation wrap I originally had placed on the intake cover and added additional Rubatex (I don't think that word is right but some of you know what I'm referring to) covering because I wanted to maintain the black look of the original PRM. I extended the wrap just aft of the blue fittings and prior to making some runs, checked for any loose areas. Once everything appeared ready to go, I hit the streets and BAM! Holy cow. The already rowdy PRM sound didn't change much but from 6-9K I can't believe how quickly the tach now zooms to redline. MUCH quicker than before, even with the original PRM install. The piping has significantly changed how this intake is operating. The Rubatex covering performs as advertised. After about 20 minutes of hard running, the entire box was cool to the touch. If this system came like this from the get-go, I can't see how it wouldn't sell like crazy. Granted, mine isn't as purty as a blue anodized AEM or INJEN, but my carbon fiber film came in yesterday and I plan to wrap it around the filter housing (right over the Rubatex) so the asthetics of the intake should improve nicely. This stuff costs alot but is VERY difficult to tell from the real deal. Overall...I really like this set-up...no water injestion problems to deal with, no cutting anywhere and nice cool air (or at least...cooler air) getting DIRECTLY into the filter which is very close to the MAF, just the way I like it.
Cost of the filter was $279 and added materials about $12. I only had one opportunity following this install to do an accelerometer run so take it with a grain of salt....especially since ambient temps were 58 degrees but I nailed a comfortable 13.67 so I'm satisfied. I'm not trying to create a drag car so the Tanabe and PRM are probably the only thing I'll do horsepower wise for now. Got to address some STB and X-brace issues, especially with the STB finding one that will fit. This intake doesn't seem to have raised the piping above OEM measures so we'll have to see what will fit.
. I'm not sure if this intake is more efficient than others because I went from OEM to PRM and couldn't compare vs any aftermarket set-up previously installed but from a design standpoint, I like what I've done and feel confident this is the right approach to getting the coolest air possible to the MAF
in the most efficient manner practical. The results sure do seem to indicate this.

 

Dude - good updates you have been giving us re the PRM - however I forsee one problem with your new setup.

The PRM's advantages are two fold:
1) The flared airhorn design at the opening of the intake; and
2) The internal inverted cone - i am not sure re the theory behind this though.

By ducting your air straight into the filter, you have effectively bypassed the airhorn, it would be interesting to see if your air is flowing at a lower velocity b/c of this