6637 Mod
Hotshot
Joined: Jul 2003
Posts: 12,177
Likes: 40
From: Newport, WA
Originally Posted by UP_There
haha! C'mon Chase!!! It's nuthin more then a hacksaw job, cleaned up by a Dremmel.....you can handle it! 
Hotshot
Joined: Jul 2003
Posts: 12,177
Likes: 40
From: Newport, WA
Originally Posted by Markadeck
I'm asking a serious question here because I really don't know. Does the 3" PVC slide inside of the neck of the 6637? And if so, I would guess the walls on the PVC are probably at least 1/8' thick. So does that reduce your flow or not? The factory tube slides right over the neck of the 6637, so if you're sticking a piece of plastic plumbing inside of the neck you are reducing the flow for the entire system. It would be like putting a piece of 3" pipe in your 4" turbo back exhaust and calling it a 4" turbo back, when in reality that little piece of 3" turns the entire exhaust into a 3" exhaust.
Elder User
Joined: Feb 2007
Posts: 857
Likes: 0
Originally Posted by Markadeck
I keep having a hard time with the 3" plastic. Why do so many folks find this a necessary step? My stock tube slid right onto the 6637 with very little effort, on my part anyway. ZX250 did most of it while I engaged in one of the other steps in the instructions. But with each filter change since, it has been very easy to put right on.
Same here. I used some brake cleaner on a rag and wiped off the rubber of the intake hose and the flange of the 6637. I had to stretch the hose a little but it slid right on. I tightened up the stock clamp and it's been working great ever since. I think the folks with the early 99's have to use a 45 degree elbow, but I didn't see the need to do anything but remove the upper part of the air box. I tie wrapped the intake are sensor near the filter and didn't bother remounting the filter minder since I've found that they're not trustworthy.
Gone, but not forgotten
Joined: Oct 2005
Posts: 5,026
Likes: 2
From: Charlotte-Fairbanks-Bflo
Originally Posted by whjco
Mark,
Same here. I used some brake cleaner on a rag and wiped off the rubber of the intake hose and the flange of the 6637. I had to stretch the hose a little but it slid right on. I tightened up the stock clamp and it's been working great ever since. I think the folks with the early 99's have to use a 45 degree elbow, but I didn't see the need to do anything but remove the upper part of the air box. I tie wrapped the intake are sensor near the filter and didn't bother remounting the filter minder since I've found that they're not trustworthy.
Same here. I used some brake cleaner on a rag and wiped off the rubber of the intake hose and the flange of the 6637. I had to stretch the hose a little but it slid right on. I tightened up the stock clamp and it's been working great ever since. I think the folks with the early 99's have to use a 45 degree elbow, but I didn't see the need to do anything but remove the upper part of the air box. I tie wrapped the intake are sensor near the filter and didn't bother remounting the filter minder since I've found that they're not trustworthy.
Post Fiend
Joined: Mar 2007
Posts: 26,966
Likes: 50
From: Texas
Originally Posted by Markadeck
I do believe everyone but those with the early 99 are simply guilty of taking the easy way out.
Actually I got scared off by a few stories about some of the filters popping off the factory tube so I chased down some exhaust pipe. I drive too many miles in a day for a filter to come off.
Lead Driver
Joined: May 2007
Posts: 5,613
Likes: 9
From: Flagstaff, Arizona
Originally Posted by F350-6
I resemble that remark.
Actually I got scared off by a few stories about some of the filters popping off the factory tube so I chased down some exhaust pipe. I drive too many miles in a day for a filter to come off.
Actually I got scared off by a few stories about some of the filters popping off the factory tube so I chased down some exhaust pipe. I drive too many miles in a day for a filter to come off.
Junior User
Joined: Apr 2007
Posts: 61
Likes: 0
From: Iowa
I thought I saw posts here saying that they has trouble with their filter coming off which sent me out to the garage to find something to ensure this did not happen. I had a 3" plastic PVC coupler and like stated above inside diameter is 3.5" with the side wall measuring 1/4" for an overall diameter of 4". The actual decrease in diameter to the air inlet is 1/2" over stock. I feel 1/2" of less air flow is OK for the peace of mind to know that the filter will not come off. When I first installed my 6637 I noticed that the filter inlet side wall is not that thick and when you put the inlet tube over this I was worried that by tightening the hose clamp that the filter might compress eventally. I just feel that 1/2" of air flow is worth the peace of mind that I know there is no chance of these connections coming apart. Still way better air flow than my stock box.
Junior User
Joined: Apr 2007
Posts: 61
Likes: 0
From: Iowa
After my last post I thought I should clarify before I offend someone. I totally agree when it comes to air flow, bigger is better. In my case though, when I read posts about filters coming off the only thing I could find in my garage was the PVC connector. I am sure I will find thin wall 4" pipe to replace my PVC connector eventually.
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Senior User
Joined: Jun 2008
Posts: 213
Likes: 0
From: Glendale, Az
Try this, its how I did mine; https://www.ford-trucks.com/forums/s...9&postcount=29
https://www.ford-trucks.com/forums/7...installed.html
https://www.ford-trucks.com/forums/7...installed.html
Senior User
Joined: Apr 2007
Posts: 314
Likes: 0
From: Southern Colorado
Ok, I give, who is selling a "Cold Air Box" for the 46637?
Thanks,
Richard
Thanks,
Richard
NAPA 6637 filter
4"od x 4 long pipe
4" constant velocity clamp
You win. I am sure you could figure out the proper order from that, but there is a link in my sig that will show you how to do it, IIRC. It is simple! If you want to get a little more complicated there is a cold air box option that just came out last week. That would be a pretty sweet little improvement.
4"od x 4 long pipe
4" constant velocity clamp
You win. I am sure you could figure out the proper order from that, but there is a link in my sig that will show you how to do it, IIRC. It is simple! If you want to get a little more complicated there is a cold air box option that just came out last week. That would be a pretty sweet little improvement.
Senior User
Joined: Dec 2008
Posts: 470
Likes: 0
From: independence,mo
is anyone running the 6637 piping from riffraff, i sent him an email yesterday and recieved a response back with pics, i am thinking of ordering it but wanted to see if anyone has some input on it, looks like clean setup.