K&N vs breadbox filter - think about it first

mark houghton · 08:15 AM

Just sharing my most recent frustration, I decided last week to ditch my stock 'breadbox' air cleaner and go with a K&N, #5163. Total height including the 1" flange is 5.125". Plenty of clearance once installed.

Guess what, I'll need to drop the engine about 1.5" in order to slide it onto the air intake housing. If not for the mysterious rubber bumper thing above the air plate - but more importantly the casting that sits about an inch high to mount that bumper crossmember - it would slide on over the lip. Not happenin'.

The moral of the story: if you're contemplating doing this for convience, it's not. And add the fact that your IC needs to come off as well. Your filter cleaning will now take a good hour out of your life.

EDIT: Got it on without dropping the engine but doubt it could be done without removing the IC...which I can live with.

Alan L · Alan L's Garage

I am not quite sure what version you have - I could measure mine in a few days. I have plenty of clearance - when it is on. But getting it on requires sneaking up on the housing from an angle and partially slipping it over til I can trick it into sitting snug over top. A sort of gymnastics. But I don't need to touch my IC.
Alan

Bucketlist · Bucketlist's Garage

I agree it is a very tight fit. I removed the silly rubber bumper thing years ago and have seen no downside. The K&N has been on there several years, it is the RU-5163 like yours. I have a RUF longneck intercooler instead of the old stock pieces which may make a difference. Maybe I don't drive mine enough to make it necessary to pull the K&N off for cleaning. I sold my old RUF airbox because I couldn't imagine going back to it. I used the extra room to install a control pressure gauge and sender above my WUR. For the oil vapor connection from the oil tank I tried a drip tank but it stayed empty so I put a paper filter on it.

mark houghton · 04-24-2025, 08:28 AM

Not one to give up. Problem was no room between the lid hinge, rear wiper motor and the metal fuel lines below it, as well as the small bracket that holds the two lines together. Gained an inch by removing the bracket, allowing the fuel lines to flex just enough to get the filter over and past them. That and the BOV manifold makes a narrow window.

Still barely able to fenagle it on, after removing the rubber bumper thingy which gained me another maybe 3/8 inch of clearance. And of course, had to cut a notch in the filter base to clear the mixture adjustment post.

Doing this with the IC on? Don't think so but I can live with that.

flightlead404 · flightlead404's Garage

Quote:

Originally Posted by Alan L

I am not quite sure what version you have - I could measure mine in a few days. I have plenty of clearance - when it is on. But getting it on requires sneaking up on the housing from an angle and partially slipping it over til I can trick it into sitting snug over top. A sort of gymnastics. But I don't need to touch my IC.
Alan

This.

I made it easier because I was replacing my sound pad, so I made a cut out above the filter which gives me slightly more room.

Alan L · Alan L's Garage

Right, I don't hsve a sound pad, not a rear wiper motor, nor a bracket on the fuel lines. They were already gone. That may have helped. And yes, a indent is gouged out for the idle adjust. The other news is you need to cock it over to do idle adjustments. I try to not let it slip off completely - to save going thru the whole process again.
Well done. Yes, you need persrverance to own a 930.
You just passed one of the tests. There are a few more of course.
Alan

mark houghton · 04-24-2025, 01:27 PM

My OEM sound pad is cut out, and helps, but still the clearance is just not entirely enough. Last resort I could have cut off maybe 1/4" of the flange to make it easier to slip in place.
No issues with the mixture adjustment post, with the notch I cut it's free and clear so won't have to cock the filter to make any adjustments.
Looking forward to the next test of my endurance. Been messing with these cars since joining this group in 2008....with a short reprieve around 2016 for reasons we care not to remember.

Alan L · Alan L's Garage

You have to pay penance for the time off (even if it was unscheduled). The rest of us never got a break while you semi- retired. We still had fuel pump issues and all sorts of conundrums to deal with.
All you had to deal with was a messy garage.
Alan

Alan L · Alan L's Garage

I suspect my air filter is a slightly shorter version than some of yours. There is a pic posted on Mark's fuel issue post.
Alan

mark houghton · 04-25-2025, 06:03 AM

Quote:

Originally Posted by Alan L

You have to pay penance for the time off. We still had fuel pump issues and all sorts of conundrums to deal with.
All you had to deal with was a messy garage.
Alan

Made me laugh! My garage was just a tad bit messy during my short reprieve. Ahh...the memories.

RarlyL8 · RarlyL8's Garage

I remember that horror show, hard to look at.

As for the K&N cone filter, the object of using those filters is not to make changing the filter easy, it is to clear out room so you can get to everything else such as the WUR without having to first remove the OE mailbox. Be sure to notch the filter for the idle mixture screw before installing.
We will soon be producing a carbon fiber air cleaner assembly that solves both of these issues. The OE filter will be retained but the shape of the housing is modified to allow access to the WUR. It weighs nothing so there is that as well.

mark houghton · 04-25-2025, 09:22 AM

Quote:

Originally Posted by RarlyL8

I remember that horror show, hard to look at.

As for the K&N cone filter, the object of using those filters is not to make changing the filter easy, it is to clear out room so you can get to everything else such as the WUR without having to first remove the OE mailbox. Be sure to notch the filter for the idle mixture screw before installing.
We will soon be producing a carbon fiber air cleaner assembly that solves both of these issues

True, which is only reason I did it. Yep, cut a notch in the filter.

Glad you're developing a nice housing retrofit to open up some room back there. I kinda did something similar at one time, cut my stock mailbox in half basically while retaining the two breather hose ports, brazed a fitting on the opening to attach a large cylindrical K&N. Served the purpose of opening things up underneath.

As for the past, I choose to forget it. Minor PTSD plagued me for years but gone now. Like crying over spilt beer.