Which air filter? - Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum
Ford Focus Forum
HomeContact UsAbout UsGalleryDiscussion ForumsMarketplace

Go Back   Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum > Ford Focus Tech Discussions > General Forced Induction

General Forced Induction The place to chat about turbochargers, superchargers nitrous systems and custom engine fabrications.

Search This Forum | Image Search | Advanced Search    

LinkBack Thread Tools Display Modes
Old 11-27-2010, 05:03 PM   #1
Focus Jr. Enthusiast
Join Date: Jan 2009
Fan#: 61668
Location: West point, Va
What I Drive: 1999 Ford Superduty, 2002 Focus

Posts: 32
FF Reputation: 1 JayMac Good Standing Member
Buy-Sell-Trade Rating: (1)
Which air filter?

I will assume that the consensus will be K&N but how big. The one I have is damaged and while trying to figure out what I have the question came up what do I need. I think the filter with the Roush kit was the RU-2820. I got that by measuring the damaged filter and using the cross reference from K&N. Strangely enough when I entered the dimensions in their site based on what I have, they said they do not have anything like that. I just started with the intake diameter and went from there.


I was wondering if I can sub the RU-5111 instead? It is a little narrower but wouldn't the limiting factor be the intake diameter anyway?

I found a kit that used the RU-1620 and that is for an even narrower intake. So I assume that there is an equation that should tell me how much filter I need but I spent that portion of my life slamming beers and as a result it is much easier to ask than re-learn math.

As long as I am asking are the dry filters any good?


JayMac is offline  
    Reply With Quote Quick reply to this message
Sponsored Links
Old 11-27-2010, 07:05 PM   #2
Focus Fanatic
bmylez's Avatar
Join Date: Apr 2009
Fan#: 64637
Location: San Antonio, TX
What I Drive: 2003 350Z Track

Posts: 3,450
FF Reputation: 23 bmylez Great Standing Member
Buy-Sell-Trade Rating: (1)
For turbo applications, as a rule of thumb, you want the biggest filter you can fit in the engine bay. FSWerks was worried that Jim's (Roushturbozx3) filter was going to be small and said he should get the biggest one possible. So find the correct diameter for your intake pipe and get the longest body length you can. Can't go wrong.
1992 Eagle Talon TSi - sold (POS)
2002 Mustang GT - sold
2002 SVTF - sold
2008.5 Mazdaspeed3 GT - cursed
2003 350Z Track - basically stock, and it runs
bmylez is offline  
    Reply With Quote Quick reply to this message

Bookmarks & Social Networks

Quick Reply

Register Now

In order to be able to post messages on the Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
What I Drive
Year, color, and model of your car. Example: 2003 Focus Centennial Edition Sedan
Your real name.
Please select your insurance company (Optional)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -5. The time now is 11:16 PM.

Copyright 2002-2015 FocusFanatics.com. All Rights Reserved : Privacy Policy : Advertise Information

Focus Fanatics Ford Focus Forum offers many fun ways for you to engage with other Ford Focus Owners from across the world. Whether it be about the aftermarket performance modifications, technical how-to's, European tuned suspension or awesome fuel economy similar to the Mazda CX-3, Audi S3, Mazda MX-5 Miata and Acura TLX. You can find all Ford Focus, Focus ST and Focus RS related information here. Join our Ford Focus discussion forums and chat with local Focus enthusiasts in your area. If you own other makes have a look at Challenger Hellcat Forum, Charger Hellcat Forum, Cadillac ATS-V Forum, Cadillac CTS-V Forum, Lexus RC-F Forum, Lexus GS-F Forum, Mercedes GLA Forum, Mercedes GLE Forum and Volvo XC90 Forum.


Search Engine Optimization by vBSEO 3.6.1