4" Exhaust VS. 5" Exhaust and Bye Bye Stack!

TLyons90

New member
Apr 22, 2013
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Greenville, SC
Figured I would do a little write up for anyone past, present, or future and the choice of going with either a 4" downpipe back or a 5". I orignally had a 4" downpipe back into a 7" SoFlo single stack. I have grown out of my stack days and had a guy interested in buying my stack so I decided since I had sold off the bed back part of my exhaust system and was going to buy another full new exhaust to go with the 5". For about the first 8" of the 5" exhaust it stays 3" then into 4" then into the 5" to be able to clear the tranny lines for the added size in exhaust. After that it is very straight forward and fits fairly well but is pretty close to a few different items which is sketchy but perfectly fine. I decided to leave the tailpiece off of my new exhaust and just run it dumped over the axle for a stealth look. Upon start up you can tell a slight bit of noise difference but nothing major. The real difference is when you start pushing on the throttle pedal and you can really hear the deeper tone as well as quite a bit more turbo whistle. Cruising down the hwy at 70 (me being use to my stack) it is very quiet with no droaning and just a real good clean sound. Also it might just be me but from normal cruising speeds both in town and on the hwy I seem to notice a very slight, less then 100 degrees, drop in EGTs. All and all I think I do prefer the 5" over the 4" for the little bit more money it is and the fact that only a handful of people run a 5" so it makes my truck stand slightly apart from the rest :thumb:

Also I do have a 3" downpipe which helps with a slight bit of sound as well as EGTs which may be a slight difference apposed to the stock downpipe. Thanks!
 

SSchmi5519

LLY Cult Leader
Oct 19, 2008
3,387
1
36
Arizona
The turn down will make you hear a little more sound. If it was the standard side exit it would be a little quieter :thumb:

I have the 4" downpipe into a 4" front pipe then it goes straight to 5" all the way back off my 472. Now that the muffler is worn in it gets real nasty when I get on it, but doesn't sound like a stock car when driving normally.

I also prefer the 5", more so for looks than anything else.


Sent from my iPhone.
 

TROJAN366

Gold Rush
Jan 13, 2012
2,474
1
38
MASS
I run an MBRP 5" on my truck most of the time. I just prefer the look of the 5" without a tip on it. Looks nice coming over the axle 5" all the way. I just put a muffler on it and it is very quiet and a super deep tone.

Edit: If I had the opportunity to do it all over again I would probably go with the Magnaflow 5". From everything I have seen the quality is great and it is also 5" starting at the front pipe unlike the other systems available.
 

TLyons90

New member
Apr 22, 2013
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Greenville, SC
The turn down will make you hear a little more sound. If it was the standard side exit it would be a little quieter :thumb:

I have the 4" downpipe into a 4" front pipe then it goes straight to 5" all the way back off my 472. Now that the muffler is worn in it gets real nasty when I get on it, but doesn't sound like a stock car when driving normally.

I also prefer the 5", more so for looks than anything else.
Sent from my iPhone.

I knew I would get a little more out of the turndown as I had a turndown on my last LLY, which I wanted, but it isnt quite as loud as I thought it would be which is a plus! Im sure that 472 sounds nasty out of a 5" :thumb:

I run an MBRP 5" on my truck most of the time. I just prefer the look of the 5" without a tip on it. Looks nice coming over the axle 5" all the way. I just put a muffler on it and it is very quiet and a super deep tone.

Edit: If I had the opportunity to do it all over again I would probably go with the Magnaflow 5". From everything I have seen the quality is great and it is also 5" starting at the front pipe unlike the other systems available.

I actually went with the Magnaflow 5" but I ordered the 01-07 kit which on Alligators website said it would fit 01-10 but upon install only 1 of the 5 hangers actally lined up so now I am going to have to take it to my buddys muffler shop and have some custom hangers welded on so it is golden!
 

Dozerboy

Well-known member
Jun 23, 2009
4,892
470
83
TX of course
I've been going back and forth on 4" or 5" system. I like having a full 5" all the out and a deeper tone. Just don't want it to loud. The cops would have the ticket filled out before I got there during my gasser days and I don't want to go down that road again.
 

mackthehack

DUH...
Apr 16, 2007
831
0
16
Magnaflow is the way to go. Running a 5" on my lbz and recently put the muffroar on. Sounds bad ass with the muffroar on.
 

TLyons90

New member
Apr 22, 2013
1,631
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Greenville, SC
I've been going back and forth on 4" or 5" system. I like having a full 5" all the out and a deeper tone. Just don't want it to loud. The cops would have the ticket filled out before I got there during my gasser days and I don't want to go down that road again.

I am not sure quite how loud my exhaust is from behind me whenever I get on the pedal but from an idle and inside the cab it is surly alot quiter then the stack was as well as having alot better tone!

Magnaflow is the way to go. Running a 5" on my lbz and recently put the muffroar on. Sounds bad ass with the muffroar on.

Really? I would of expected it to take a little away but I might have to do a little research on 1 :thumb:
 

chevytuf01

Dirty Deeds
Jul 2, 2010
261
0
0
Rileyville Virginia
Before my stack I had , LML driverside exhaust manifold and a Profab 3" downpipe... along with the 5" exhaust from a old website called rpmoutlet (think they went out of biz) and it had that section of 3" off the down pipe and then went to 5" i didnt run a muffler & had a 7" tip and i loved the way it sounded !!!!!! Wasnt loud at idle ... but above 2000rpm it would scream
 

TLyons90

New member
Apr 22, 2013
1,631
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Greenville, SC
Before my stack I had , LML driverside exhaust manifold and a Profab 3" downpipe... along with the 5" exhaust from a old website called rpmoutlet (think they went out of biz) and it had that section of 3" off the down pipe and then went to 5" i didnt run a muffler & had a 7" tip and i loved the way it sounded !!!!!! Wasnt loud at idle ... but above 2000rpm it would scream

Basically my exact setup except 1" smaller on the tip :thumb:
 

totalanarchy

New member
Oct 11, 2013
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5 inch the quicker and more you can get out the better plus it sounds amazing!! i happy with my 5 inch turbo back
 

Devon

broke my curse
May 2, 2010
807
0
0
Hinsdale ma
Just put a diamond eye 5" exhaust on my new lly. It's bone stock so it really doesn't get too loud even straight piped. I'm sure once I add a tune to the truck it'll scream. If I had to buy another kit, I would have done a Mbrp or magnaflow. Don't really like how the diamond eye comes out the back of the truck too much. But she sounds good! I need a 3" downpipe aswell.


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TLyons90

New member
Apr 22, 2013
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Greenville, SC
5 inch the quicker and more you can get out the better plus it sounds amazing!! i happy with my 5 inch turbo back

Downpipe back :thumb:

Just put a diamond eye 5" exhaust on my new lly. It's bone stock so it really doesn't get too loud even straight piped. I'm sure once I add a tune to the truck it'll scream. If I had to buy another kit, I would have done a Mbrp or magnaflow. Don't really like how the diamond eye comes out the back of the truck too much. But she sounds good! I need a 3" downpipe aswell.


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With my stack setup I went with a 4" DE downppipe back and the fitment and quality was horrible to me! Also have heard that from several others so I knew not to make that mistake twice and had heard some good things about the Magnaflow plus it was the cheapest! :D