5" versus 4" exhaust

Robert78.5 · 11-27-2008, 06:40 PM

A freind of mine has a Ford 2005, he wants to change exhaust and get rid of cats. He wants good fuel economy. He has the hi flow air filter and an Edge Box, is he better to go to 4" or 5" exhaust? The truck is used for his 5th wheel camper. It is diesel

liftedtrucks4me · 11-27-2008, 06:42 PM

I would go with 5. More air flow through the pipes and its a little louder which is cool.

87c10slammer · 11-27-2008, 06:47 PM

im assuming its deseil.. if it is then go withthe 5s... they sound nasty

mrjohnwayne · 11-27-2008, 08:07 PM

5" won't do anything except lighten your pocket book more. You will have no more gain (performance wise) over the 4"

leolkfrm · 11-27-2008, 08:31 PM

I would check with customer support at edge, tell them what you have and ask what you can do

merlin5577 · 11-27-2008, 09:08 PM

Quote:

Originally Posted by mrjohnwayne

5" won't do anything except lighten your pocket book more. You will have no more gain (performance wise) over the 4"

+1.

With the stock turbo and a (relatively) stock truck the 5" will not help perfomance any, and with the catalytic converter removed might actually hurt it. Turbochargers need a certain amount of back pressure to fuction properly, and in this case, bigger is not better. A 4" exhaust will work just fine.

stumpuller454 · 11-28-2008, 08:17 AM

Quote:

Originally Posted by mrjohnwayne

5" won't do anything except lighten your pocket book more. You will have no more gain (performance wise) over the 4"

PRECICLY! unless it it heavily modified, 4" is the way to go dude....

76silverado · 11-28-2008, 08:30 AM

4" with stacks through the bed!

junior3382 · 11-28-2008, 08:36 AM

I agree with merlin here, you need to consider the backpressure. ESPECIALLY when running a stock turbo setup. If you are trying for better mileage, try upgrading the whole air flow system front and rear. Allow it to breathe better, but I would not remove the cat. I would also check out bullydog, they have some excellent upgrades for disels and the cost is reasonable. Not to mention the power and mileage increase, especially for towing.

stumpuller454 · 11-28-2008, 09:06 AM

my 05 F550 gained 1 mpg without its cat, plus then the turbo is REALLY loud, BUT THE EXHAUST REAKS, it`ll K.O. you in no time!

11-27-2008, 06:40 PM	#1
Robert78.5 Full Member Join Date: Sep 2006 Location: Manitoba Posts: 34	5" versus 4" exhaust A freind of mine has a Ford 2005, he wants to change exhaust and get rid of cats. He wants good fuel economy. He has the hi flow air filter and an Edge Box, is he better to go to 4" or 5" exhaust? The truck is used for his 5th wheel camper. It is diesel Last edited by Robert78.5; 11-27-2008 at 07:04 PM.

11-27-2008, 08:07 PM	#4
mrjohnwayne Senior Moderator Join Date: Apr 2005 Location: Texas Posts: 3,722	5" won't do anything except lighten your pocket book more. You will have no more gain (performance wise) over the 4" __________________ John Wayne 2000 F-350 7.3L Powerstroke 4x4

11-27-2008, 08:31 PM	#5
leolkfrm Senior Member Join Date: Mar 2008 Location: N.Y. Posts: 4,300	I would check with customer support at edge, tell them what you have and ask what you can do __________________ 4 wheels move the body 2 wheels move the soul B.W.A.I

11-28-2008, 08:30 AM	#8
76silverado Senior Member Join Date: Oct 2008 Location: NW Arkansas Posts: 355	4" with stacks through the bed! __________________ http://s513.photobucket.com/albums/t...t=HPIM1105.jpg '76 Silverado10 Custom Deluxe, 350 4barrel, th350 auto FULL TIME FOUR WHEEL!

11-28-2008, 08:36 AM	#9
junior3382 Senior Member Join Date: Mar 2007 Location: Currently, I live in Lancaster county, Pennsylvania. Posts: 3,170	I agree with merlin here, you need to consider the backpressure. ESPECIALLY when running a stock turbo setup. If you are trying for better mileage, try upgrading the whole air flow system front and rear. Allow it to breathe better, but I would not remove the cat. I would also check out bullydog, they have some excellent upgrades for disels and the cost is reasonable. Not to mention the power and mileage increase, especially for towing. __________________ *The Blazer is dead, so I pumped her with lead, laid her to bed, and bought a FORD instead!*

11-27-2008, 06:42 PM	#2
liftedtrucks4me Senior Member Join Date: Jan 2008 Location: Southwest Virginia Posts: 143	I would go with 5. More air flow through the pipes and its a little louder which is cool.

11-27-2008, 06:47 PM	#3
87c10slammer Banned Join Date: Mar 2008 Location: levittown pa Posts: 2,197	im assuming its deseil.. if it is then go withthe 5s... they sound nasty

11-28-2008, 09:06 AM	#10
stumpuller454 Senior Member Join Date: Dec 2007 Location: Grande Prairie, AB Posts: 2,043	my 05 F550 gained 1 mpg without its cat, plus then the turbo is REALLY loud, BUT THE EXHAUST REAKS, it`ll K.O. you in no time! __________________ SUPERCHARGED 454 K2500 GMC! 450hp and 600ft/lbs http://www.youtube.com/watch?v=WJ27RJHfJKE "sailing with Captain Morgan often!"

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