Do I need a downpipe with a 4" exhaust system? - Ford Powerstroke Diesel Forum
6.0L Performance Parts Discussion What has or has not worked for you?

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 15 Old 10-09-2012, 04:21 PM Thread Starter
Compression Ignition Addict
 
Erwin8r's Avatar
 
Join Date: Jan 2010
Posts: 220
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Do I need a downpipe with a 4" exhaust system?

Ok, I tried this in the general section, but it was probably the wrong place for it. I want to get a "Turbo Back" 4" exhaust system, and am wondering if it is worth the hassle to use a 4" down pipe (or a 3.5" aftermarket) instead of just keeping my stock down pipe and welding the 4" system to it. What do you all think? I understand that the stock one is 3.5", so what would the advantage of a, say MBRP 3.5" down pipe be? I want to lower my EGT's, and of course, maybe get a small bump in ponies. Thanks!

2003 6.0 PSD Extra Cab SB 4x4
35" Toyo MT's
ARP Studs
BPD EGR Cooler
AFE Stage 2
Rhinoliner
Big-*** Fuel Tank (47 gallon?)
Erwin8r is offline  
Sponsored Links
Advertisement
 
post #2 of 15 Old 10-09-2012, 04:59 PM
Compression Ignition Addict
 
Join Date: Jan 2012
Location: Fallon, Nv
Posts: 2,403
Thanks: 54
Thanked 11 Times in 10 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
My OEM down pipe was 3 inches, so the 3.5 did help. A 4 inch will work, but it's mucho tighto in there when you try going 4 inches.

Karl and his 2003 6.0

Barefoot Accelerator Pedal
TRICO Force wiper blades
Yellow Military Aircraft Valve Stem Caps
Offensive "Stick Family" Decal
Big Ol'Honkin 1 1/4" Shank Receiver Hitch


WHAT!?! I was trying to list stuff that everyone else
hasn't already listed for their truck!

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Karls03 is offline  
post #3 of 15 Old 10-09-2012, 08:51 PM Thread Starter
Compression Ignition Addict
 
Erwin8r's Avatar
 
Join Date: Jan 2010
Posts: 220
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Quote:
Originally Posted by Karls03 View Post
My OEM down pipe was 3 inches, so the 3.5 did help. A 4 inch will work, but it's mucho tighto in there when you try going 4 inches.
Did your 4" system come with the 3.5" down pipe? What model did you go with? Thanks!

2003 6.0 PSD Extra Cab SB 4x4
35" Toyo MT's
ARP Studs
BPD EGR Cooler
AFE Stage 2
Rhinoliner
Big-*** Fuel Tank (47 gallon?)
Erwin8r is offline  
post #4 of 15 Old 10-09-2012, 09:31 PM
aussie=effie
 
bob harris's Avatar
 
Join Date: Apr 2010
Location: melbourne, australia
Posts: 286
Thanks: 0
Thanked 3 Times in 3 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Smile 4 inch exhaust

I BOUGHT MBRP 4 INCH PERFORMANCE SYSTEM BUT THE 4 INCH DOWNPIPE WAS FOULING ON GEARBOX. FITTED THE ORIGINAL 31/2 DOWNPIPE THEN INTO THE 4 INCH PIPES AND IT WORKS JUST FINE
bob harris is offline  
post #5 of 15 Old 10-09-2012, 09:33 PM Thread Starter
Compression Ignition Addict
 
Erwin8r's Avatar
 
Join Date: Jan 2010
Posts: 220
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Quote:
Originally Posted by bob harris View Post
I BOUGHT MBRP 4 INCH PERFORMANCE SYSTEM BUT THE 4 INCH DOWNPIPE WAS FOULING ON GEARBOX. FITTED THE ORIGINAL 31/2 DOWNPIPE THEN INTO THE 4 INCH PIPES AND IT WORKS JUST FINE
Thanks for the info. So I guess my next question is, do some trucks have 3" vs. 3.5" down pipes stock?

2003 6.0 PSD Extra Cab SB 4x4
35" Toyo MT's
ARP Studs
BPD EGR Cooler
AFE Stage 2
Rhinoliner
Big-*** Fuel Tank (47 gallon?)
Erwin8r is offline  
post #6 of 15 Old 10-10-2012, 12:55 AM
Premium Member
 
snafu!'s Avatar
 
Join Date: May 2012
Location: Anchorage
Posts: 1,469
Thanks: 19
Thanked 50 Times in 43 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 1 reviews
I got flowmaster and it came with a 4" down pipe, didn't really have any problems sliding it up to the turbo had to turn it just right and it went right up there. Kind of like a puzzle. All truck are a little different though, I've heard of people having trouble with the 3.5" down pipe.

The only reason I got flowmaster is because mbrp was 3 to 4 weeks out when I ordered mine and I'm impatient. Lol

Cameron
2006 F250 Lariat CCSB
Comp Turbo 64/88 compounds
Warren 285/100
ODAWG ported intake
R&R rods, mahle pistons, stage 2 colt cam
Built Trans
Water/Meth
snafu! is offline  
post #7 of 15 Old 10-10-2012, 07:17 AM
Compression Ignition Addict
 
xjeeper's Avatar
 
Join Date: Jun 2008
Location: Naperville IL
Posts: 573
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
I have run all 3 ways (stock, 4" flowmaster, and now 3.5" mbrp), I felt that the stock downpipe spooled better in normal driving, the 3.5" is good all around, and the 4" was a pain to fit in the truck.
xjeeper is offline  
post #8 of 15 Old 10-10-2012, 07:20 AM
Compression Ignition Addict
 
Join Date: Jan 2012
Location: Fallon, Nv
Posts: 2,403
Thanks: 54
Thanked 11 Times in 10 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
If I'm not mistaken, exhaust tubing is measured on inside diameter. All I know is that I checked the box for a 3.5 MRBP down tube and it was larger than the OEM tube on my 2003. I already had a 4" Dynomax cat back and I connected the 2. A friend has a 4 inch on his 03 and it's a tight fit.

Why did I buy exhaust twice? Because we miss measured and thought that the down tube was 3.5 inches. Turns out it was 3 inches into the resonator, then 3.5 from cat to tail pipe.

Last edited by Karls03; 10-10-2012 at 07:26 AM.
Karls03 is offline  
post #9 of 15 Old 10-10-2012, 08:01 AM Thread Starter
Compression Ignition Addict
 
Erwin8r's Avatar
 
Join Date: Jan 2010
Posts: 220
Thanks: 0
Thanked 0 Times in 0 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
Sounds like A 4" MBRP with a 3.5" down pipe is the way to go; and maybe the earlier 6.0's had less space to work with?

2003 6.0 PSD Extra Cab SB 4x4
35" Toyo MT's
ARP Studs
BPD EGR Cooler
AFE Stage 2
Rhinoliner
Big-*** Fuel Tank (47 gallon?)
Erwin8r is offline  
post #10 of 15 Old 10-10-2012, 08:18 AM
Compression Ignition Addict
 
JIM_C's Avatar
 
Join Date: Nov 2008
Location: Tucker, GA
Posts: 497
Thanks: 4
Thanked 5 Times in 3 Posts
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Feedback Score: 0 reviews
You definitely want to get rid of the stock downpipe on an '03 6.0 as they are not mandrel bent. Meaning it's a crimped up POS where it turns to go to the cat.

2014 F250 CC SB 4x4, 6.2, Platinum
2003 F250 CC LB 4x4, 6.0 w/auto (SOLD)
JIM_C is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Ford Powerstroke Diesel 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:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









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
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome