4" Magna-Flow downpipe rubbing crossover pipe

Brian460 · #1 (**permalink**) 01-01-2008, 11:21 PM

I have had my 4" system on my truck for 3 years now, a couple months or so ago I really started noticing a decrease in performance and mileage and greatly increased turbo lag.

This is becuase the dp was rubbing on the expansion joint on one of the turbo up-pipes and wore a hole in it causing a pre-turbo exhaust leak. I was just wondering if anybody else had experienced this, and if not may be something to look at before it happens on your truck.

Benchwrench · #2 (**permalink**) 01-02-2008, 01:27 AM

the short 4" downpipe Magnaflow offers is supposed to have an "indent" at the intersection where it is closest to the up-pipe.
Just wondering if yours came with the indentation.

B327Thr · #3 (**permalink**) 01-02-2008, 01:46 AM

This is on the 4" down pipe, not the 3.5" right?

Brian460 · #4 (**permalink**) 01-02-2008, 08:16 AM

4" is correct and there is no indentation on my pipe.

Benchwrench · #5 (**permalink**) 01-03-2008, 08:59 PM

bummer dude, I wonder when Magnaflow started "modifying" their downpipe because I have their system and it has the indent.
See if you can get Magnaflow corprate to fix your issue for you. The least will be a replacement downpipe.

TreeTech · #6 (**permalink**) 01-03-2008, 09:34 PM

I just installed my magnaflow 4in" turbo back a couple of weeks ago. Mine has the indent to clear the up pipe. I have had no issues so far and I do have the 4in down pipe.

rchouser · #7 (**permalink**) 01-04-2008, 06:15 AM

Did the "indented" 4 inch down pipe go in without any issues (I have seen fire walls pressed, heard about people having to "re-shape" (hammer mod) their 4 inch for clearance issues. How tough is the instal with the Mangflow 4 inch down pipe in and 06 350 AT CC SWD PSD? I am shopping now for an exhaust system. thanks rc

Brian460 · #8 (**permalink**) 01-04-2008, 07:24 AM

Mine in the '03 went in with a rubber mallet but once it was up there it moved freely so I didn't think it was rubbing anything. Guess I was wrong. LOL

Benchwrench · #9 (**permalink**) 01-04-2008, 11:44 AM

If you read down to post #5 in the below thread you will find a real slick trick regarding the install of the 4" downpipe. It makes a HUGE difference and doesn't require ANY firewall mutilation.
http://www.ford-trucks.com/forums/65...lamp-spec.html
P.S. This afore mentioned "trick" in post #5 should be included in a "tech tip" section because it worked so well, I had to pass it along.