Exhaust Back Pressure good or bad

[KEVINL]

Ever since I have put on my S364 The exhaust clamp wont hold so it blows apart right after the cab. So I have noticed lower overall egt's and much better sound and you can hear the turbo alot more as well.

I was thinking of just removing the rest of the exhaust and putting a turn down on it.

I have noticed though it seems like there is lag from a dead stop but maybe the fact it is 110 degrees has more to do with that.

It seems to me the less back pressure after the turbo the better but I have heard conflicting info.

What do you guys think?

 

[DAVe3283]

Turbos work on a pressure differential, so the less pressure after the turbo, the bigger the pressure differential is, and the better it will work. I'd get rid of the backpressure, either with a turn-down, or a bigger exhaust, depending on your preference for the looks.

 

[Chevy1925]

Ever since I have put on my S364 The exhaust clamp wont hold so it blows apart right after the cab. So I have noticed lower overall egt's and much better sound and you can hear the turbo alot more as well.

I was thinking of just removing the rest of the exhaust and putting a turn down on it.

I have noticed though it seems like there is lag from a dead stop but maybe the fact it is 110 degrees has more to do with that.

It seems to me the less back pressure after the turbo the better but I have heard conflicting info.

What do you guys think?

just FYI kevin, your cab will drone with a turn down right behind the cab, even with a muffler. I dont know how much drone bugs ya but it gets annoying when towing thats for sure. the best fix for the drone i found was adding a second turbo

 

[KEVINL]

yeah it drones but not as bad as my wifes G8. Also I just turn up the stereo if it gets annoying.

The truck will probably have a S480 as well in the future but I will do a built motor first

 

[kenny]

Straight pipe it to the back. to me it sounds pretty good.

 

[KEVINL]

It is already straight pipe 4" inch I am just debating whether or not to keep the rear section of the exhaust

 

[kenny]

how the hell do you blow off the exhaust then, haha? Is it welded? oops, just read you have only a clamp. On mine I tack welded all teh joints to prevent this from happening and also prevents the tubes from rotating. Strap clamps are also bad ass and would not blow off too.

 

[DIESELMAFIAPER.LB7]

Ever since I have put on my S364 The exhaust clamp wont hold so it blows apart right after the cab. So I have noticed lower overall egt's and much better sound and you can hear the turbo alot more as well.

I was thinking of just removing the rest of the exhaust and putting a turn down on it.

I have noticed though it seems like there is lag from a dead stop but maybe the fact it is 110 degrees has more to do with that.

It seems to me the less back pressure after the turbo the better but I have heard conflicting info.

What do you guys think?

Mine lags bad outta the hole with a mufflye without its always been laggy?

 

[Chevy1925]

how the hell do you blow off the exhaust then, haha? Is it welded? oops, just read you have only a clamp. On mine I tack welded all teh joints to prevent this from happening and also prevents the tubes from rotating. Strap clamps are also bad ass and would not blow off too.

thats not what the exhaust layin in the back of my truck says lol .

 

[kenny]

thats not what the exhaust layin in the back of my truck says lol .

prolly cause you didna put it on right...

 

[Chevy1925]

prolly cause you didna put it on right...

why does everyone keep tellin me that !?!?! :rofl:

 

[kenny]

why does everyone keep tellin me that !?!?! :rofl:

You can tighten the crap outta those things bro. It holds my exhaust to my downpipe cuz its ceramic coated. It even necks down from 5" to 4" after the clamps and I seen over 100psi drive pressure so I know it sees some force on it. It also holds the pipes on my LS1 crawler even smashed rocks and it still on there, hehe...

 

[Chevy1925]

You can tighten the crap outta those things bro. It holds my exhaust to my downpipe cuz its ceramic coated. It even necks down from 5" to 4" after the clamps and I seen over 100psi drive pressure so I know it sees some force on it. It also holds the pipes on my LS1 crawler even smashed rocks and it still on there, hehe...

i know, i was kidding :hug:

 

[kenny]

i know, i was kidding :hug:

haha...i figured you were...

 

[baggedLB7]

Dont know what kind of a diff there is but my buddy owns a muffler shop and he showed me some dyno numbers on his 05 Dodge one with a 4" and one with a 5" and the dyno run with the 5" was lower on hp than the 4" its been a while ago and I dont remeber the how much diff but he ended up putting the 4" back on.
The truck was nothing speciel just your typical bolt on stuff.