So, thanks to Rennlister camsoccer, I was able to score an EVOM airbox for my 997.1 for free (always a nice price). Installed it today with some help (as usual) from Rennlister (and all around nice guy) USMC_DS1. In addition, I also managed to get my hands on a 997.2 airbox which we fiddled with a bit.

Here are my thoughts, observations:
1) The EVOM is ridiculously easy to install. As in "that's it? That's all I have to do?" If you have all the brackets (mine was missing a bracket, so had to fab it... here's a tip: when drilling a metal piece, don't be an idiot and try to hold it with your hand. Especially when it has sharp metal edges. And if you are dumb enough to do that, try not to bleed on your car) it only takes about 5 minutes.

2) There's a lot of conjecture and claims related to these, both pro and con. Here are my observations so far. (Bear in mind, this was free for me, so I'd like to think I'm not too biased by the "I paid money for this, it'd better work" mentality.)
- The sounds is much improved, especially over 4,000 RPM. Has a nice visceral honk/wail to it. I like it. A LOT. (This, btw, is with a FisterD exhaust.)
- It seems to me to have more midrange grunt and the power delivery just seems a bit smoother. I picked up a friend for dinner who'd ridden in the car just yesterday, and hadn't even mentioned the upgrade when she asked "Did you do something to the car? It feels faster." So, it would appear my "butt dyno" isn't the only one that thinks there's something there.

All in all, I think it was a bit of time well-spent and an upgrade I'm very pleased with.

Now for the second part. I, like a lot of guys, have been very curious about the prospect of fitting a 997.2 airbox to 997.1 car. Namely, mine. To that end, I bought a cheap 997.2 airbox on eBay. When I had my airbox out today, we fit the 997.2 airbox into the space.
Pros:
- Yes, it actually fits. In fact, it fits better than the 997.1 airbox, IMHO.
- In order for it to function, you'll need the "snorkels" from the wing or spoiler (I'm adding a ducktail to my car) down to it.
- You'll also need to get a shorter oil filler tube.
- Looking at the 997.2 airbox, there are a number of layers to mesh (wire and plastic) between the filters and the throttle body that I can't think of a reason for being there; it would appear they would just add turbulence to the air coming in. Can anyone think of a reason they would be there?
- The air outlet from the airbox to the throttle body will have to be pretty much completely redesigned. Looking at the airbox, it would appear to be plastic welded. I'm going to Dremel it apart and take it to a rapid prototyping place in town and see if I can't get one designed and 3D printed that will allow the proper routing of air to a GT3 throttle body and IPD plenum.

I'll keep y'all updated as I progress on the 997.2 airbox project. Oh, and if anyone has a spare 997.2 airbox laying around that they'd like to contribute to the effort (or sell for cheap), please PM me.

 

Good info. Thanks for sharing your research.

To work correctly, the MAF sensor, downstream of the filters, needs the mesh grid between the filters and the throttle body.

.

 

Okay, good to know.

 

LOVE THE SOUND. Totally and utterly addicted to it. EVOM + FisterD exhaust = Automotive crack.