It's got to be the lack of available air to the top and side of the filter that's responsible for the poor performance. 2" of added length isn't going to make or brake the intake though I can cut it down more to make up for the stack. For now, I made a temporary top for the air box (pics 6 and 7) and reshaped the wheel liner giving the filter some more breathing room. (pics 1 and 2). Pic 1 also has the temp. back of the air box and pic 2 shows the wheel side of the liner after reshaping. The coupler at the t.b. was just a little jacked up last night due to the stack and enormous filter not fitting well. I installed the stack cocked to one side, tilting the filter which allowed for everything to fall into place as it did with the smaller filter. If this were done anywhere else it would be a problem as I understand it but the filter is not necessarily a part of the intake. It's "pre-intake" until the very base of the filter or in this case, the velocity stack.
I'm 95% confident this will do the trick but time will tell. The air box is totally sealed off. Taped the shit out of it and will do the same when installing the old filter to test. While everything is apart for the header install, I plan to make a back and larger top for the air box, open up the core support so air can enter this cavity though the grill pre-radiator and possibly cut the blank rubber end off the large filter, chop up the old filer and use it to adhere filter media to this once useless part of the filter. I'm sure I can find a reliable epoxy to make the union.
Most filter companies aren't adding filter media to the end or installing inverted cones made of filter media like Apexi still is because it adds to much to the final cost and isn't worth it, so said Injen, once (still?) makers of Amsoil filters. Injen has a small built in stack but Amsoil doesn't because Amsoil sucks. I was told the added filter media in this area will increase flow by 7%. Guess most are racing around to make the cheapest filter within reason to compete among each other.
Edit 3/1/18 - spoke w a guy at Blox. Explained everything from intake to exhaust. It appears that I may have maxed out my old tune. Last tune was for the 4" pipe. Since, I did all the intake side mods that dropped my e.t. a 1/2 second. The tune and/or ecu is possibly no longer able to compensate fuel for the added air flow. Not getting another tune until the headers go on. Bummer.
Edit 3/4/18 - I think it is tune related though not so sure it's too lean. I think it's too rich. Ever since the 4" intake tune, I get a lot of soot at the exhaust tips. Back of the FX getting dusty quicker as well. I think my tuning maestro has got me a bit too rich and now this stupid huge filter along with the stack is making it difficult for the ecu/uprev to make the right adjustment.
The time it takes soot to noticeably build up in the exhaust tips has decreased. Them shits gets black quick now. I've read many say you'll run too lean with this or that minus a tune but I've read a few that have indicated just the opposite and they made compelling arguments. Guess I'll find out soon enough.
