So im running a forged 355 with a d1sc and ive got the 7.65 crank pulley and the 3.4 blower pulley and my blower is maxed at 11 psi. I am at 5600 above sea level, and im looking to gain a few more pounds. I will be getting the 4" mufflex intake soon, but i want to get a large filter on there to get more boost. What are you guys running? Post pics if you can.

 

How big is the current filter? Here is mine but I actually had a HUGE 4" filter pt# KNN-41-1400 . Just couldn't find a spot to put it at the time.
Here is mine. Is yours smaller than this? pt# KNN-RE-0870
http://fbodyeurope.org/Gallery/main....serialNumber=2

 

I collected this list when I was looking around...

K&N Filter
4" Inlet
7" Long
Part number RU-2590

K&N Filter
4" Inlet
5" Long
Flange Length .625"
Part Number RU-2520

K&N Filter
4" Inlet
9" Long
Flange Length 1.75"
Part number RE-0870

K&N Filter
4" Inlet
7" Long
Flange Length .625"
Part number RF-1015

K&N Filter
4" Inlet
8" Long
Flange Length 1.75"
Part Number RF-1027

 

9" K&N cone filter here.

 

I'd check out Amsoil Ea Filters while you're at it.

You can get Inlet Diameters up to 6inches, Length up to 10inches, Tapered, Non-tapered, and they have reverse cones at the top of the media to increase surface area.

Here's a dirty picture of mine, I believe its 9.5 inches long w/4in ID:

 

Kredz28:

Summit Racing:

SUM-239302

Shape: Conical
Length (in): 9.188 in.
Inlet Flange Inside Diameter (in): 4.000 in.
Top Diameter (in): 4.750 in.
Bottom Diameter (in): 5.875 in.

 

This is the filter I am currently using


Here's a better pic of it actually in my car. Once I changed from the filter the ATI kit came with to this larger one, I saw a slight increase of about 2#'s.



The biggest gain I saw in boost, was after I installed this metal inlet tube. Compared to the hard plastic inlet tube from ATI, I saw a gain of 3-4#'s of boost!