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4" or 5" exhaust

1K views 10 replies 9 participants last post by  solofront 
#1 ·
:usflag The future of my truck mods is this: TC, Intercooler, Chip, DP, & exhaust. With my current mods and looking at my future mods, does a 5" exhaust make sense or will a 4" work just fine. I plan to have this truck a very long time and intend to baby it(sorry guys, I resisted, but I did grow up). Just wondering, all things being equal, what difference could I expect to see from a 4-5" exhaust.:thanks:
 
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#2 ·
A 4" exhaust will do you just fine. Unless you plan on going with much bigger injectors and a bigger turbo...there just isn't a reason to go to a 5" exhaust. In fact...without the injectors and turbo...you may lose a little bit on the bottom end by going with a 5" exhaust.
 
#3 ·
There is NO performance gain from 4 to 5 inch exhausts, just noise differance...
 
#4 ·
i agree there is'nt a real difference between 4' and 5' your not going to gain anything i have a 4' turbo back and its fine.
 
#5 ·
I ended up with 5" by accident, when Tymar sold out of 4" on the day I planned to pick mine up. Dale gave me a good deal on the 5". I suspect that the 5" is responsible for my low torque versus HP (250 hp, 430 tq), but the EGTs are sure low, and I like the throatier sound of the 5". I still like the looks from people who look under my truck and see the huge exhaust ;)

Regards,
Michael Pliska
 
#6 ·
:pointlaugh
Michael said:
I ended up with 5" by accident, when Tymar sold out of 4" on the day I planned to pick mine up. Dale gave me a good deal on the 5". I suspect that the 5" is responsible for my low torque versus HP (250 hp, 430 tq), but the EGTs are sure low, and I like the throatier sound of the 5". I still like the looks from people who look under my truck and see the huge exhaust ;)

Regards,
Michael Pliska
Its too bad they have to lay down to see under the thing....:pointlaugh
 
#8 ·
5" sounds so much better then 4" on our 7.3s. i made two identical exhausts one using a 3.5" downpipe and a 4" side pipe, the other with a 4" downpipe and a 5" side pipe the difference in sound quality is big, i did the 5" for asthetics and didnt even expect a difference in sound, but boy was i surprised when i heard the difference.
 
#9 ·
CSIPSD said:
There is NO performance gain from 4 to 5 inch exhausts, just noise differance...
Agreed.

Michael said:
I suspect that the 5" is responsible for my low torque versus HP (250 hp, 430 tq),
Interesting. I made like 406 and 880 and I have 5". I kind of doubt the size of the exhaust has much to do with it but who knows. :shrug:
 
#10 ·
Go with the 3.5" DP & 4" exhaust. It's my favorite all around setup.

I'm currently trying special chip tuning to regain low end torque lost at low RPM with the big Exhaust.
 
#11 ·
My 5" is awesome,
pretty quiet though, (sorry muffler, your coming off soon)
my egts dropped quite a bit too!!
 
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