I just purchased this K&N filter to wrap up my turbo s2000 install and opened the package to find a hole in the top of the filter.

Does anyone have any idea what this is about, when I ordered it, the picture at summit racing showed a chrome top to it.

This is what K&Ns site shows

I think i have that exact filter. I'll have to dig up the part number. It was one of the few that had a 4" inlet for my gt3076r. They have another one just like it but with two holes.

I thought it was werid that they would let unfiltered air in like that but I think to make a filter that size still flow well it was neccessary. That was my only logical assumption. I would be curious to hear k&n's explenation.

exactly the same turbo i bought it for

I seriously doubt its there to let air flow in, K&N wouldnt be that sloppy. That filter is not gonna be a big restriction in any case.
I bet its some sort of through-bolt hole to attach the filter.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Flashmn &raquo;</TD></TR><TR><TD CLASS="quote">I seriously doubt its there to let air flow in, K&N wouldnt be that sloppy. That filter is not gonna be a big restriction in any case.
I bet its some sort of through-bolt hole to attach the filter.</TD></TR></TABLE>


I bought it off of thier universal section

Ams oil has fiberous filters in anysize check there site. They catch more dirt but I think it flows less.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Flashmn &raquo;</TD></TR><TR><TD CLASS="quote">I seriously doubt its there to let air flow in, K&N wouldnt be that sloppy. That filter is not gonna be a big restriction in any case.
I bet its some sort of through-bolt hole to attach the filter.</TD></TR></TABLE>

No this is not the case. The hole goes straight through. The filter uses a standard hose clamp to secure it. This is definantly some sort of air bypass hole but why it is there I am still not sure.

My guess would be it is to put a hose in for the PCV or hose from the valve cover in. Or it could also be for nitrous.Why would an air filter company make a filter with a hole in the top to let air thru? kinda defeats the pupose of using a filter..right?

It does not have a lip or anything to mount a hose of any sort. I highly doubt that is what they intended on using it for.

I just called K&N and they said they where for hoses. That supprised me because I don't know what would keep it from coming out or loose. He said not to run without a hose on for obvious reason but I haven't had anything there for 2000 miles now. I might try and find something to plug it but I surely don't want to suck anything through it. Hmm....

All the other 4" inlet filters don't taper enough for my tight squeeze. I have a a/c kit that puts teh turbo on the passanger side so space is tight between the inlet on the turbo and my radiator/fan.

RU-5121 -- That is what is pictured above.
Footnote 1: Top has 7/16" vent standard

hose for what

They said it is a universal filter so it could be for anything. Crankcase vent for example. I know my first turbo setup had an intake with a nipple for a crankcase vent. I don't need it for my open breather setup.

I want to plug it but I'm not sure what to use. I'm afraid any type of tape would just get sucked through. maybe some type of 7/16 plug could be used??

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Why would an air filter company make a filter with a hole in the top to let air thru? kinda defeats the pupose of using a filter..right? </TD></TR></TABLE>
Indeed and just plain common sense would dictate it.

those holes are for Domestic IAT sensors, that filter is the what is on my Ford F150 and what was on my mustang.

camaros and corvettes have the same hole but different shaped filter, they are just a press in type application

If you figure something out let me know

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidwestAutoWorks &raquo;</TD></TR><TR><TD CLASS="quote">If you figure something out let me know</TD></TR></TABLE>

New filter.

Find me one with the same dimensions with a 4 inch opening and I would have no problems with that, unfortunately I can not

Duct tape?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidwestAutoWorks &raquo;</TD></TR><TR><TD CLASS="quote">Find me one with the same dimensions with a 4 inch opening and I would have no problems with that, unfortunately I can not</TD></TR></TABLE>


I mentioned AMSOIL fiber element.

https://www.amsoil.com/storefront/eaau.aspx
https://www.amsoil.com/product...s.pdf

RU2520?? Thats what I use. Works good for my limited space.

Or.......

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MidShipCivic &raquo;</TD></TR><TR><TD CLASS="quote">


I mentioned AMSOIL fiber element.

https://www.amsoil.com/storefront/eaau.aspx
https://www.amsoil.com/product...s.pdf</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by KeyserSoze &raquo;</TD></TR><TR><TD CLASS="quote">RU2520?? Thats what I use. Works good for my limited space.</TD></TR></TABLE>

i believe k and N makes a plug try contacting them

just go to the hardware store...they have all sorts of plugs. just make sure it has a good sized lip so it stays put. or even get a short bolt, 2 washers, and a nyloc.