is there any reason that an LB7 would be louder than an LLY with the exact same exhaust system installed on both?

reason I ask is... I had purchased a complete system for my LLY, but the EGR and ECU didn't like it so I sold the exhaust system to a buddy here in town for his LB7.

He just wrote and said he isn't sure he likes it since its so much louder and sounds like a gasser now.

when I had this on my truck it was only a slight rumble and that was it. Otherwise it was very quiet. Now, the same type of pipes put on a gasser of course would be VERY loud..

anyone have both, or heard both??? any reason one would be louder than the other?

If anything, I think the LLY is QUIETER than the LB7 with the exact same exhaust system.....At least that's what I found with the dynomax system...

any reason why the LB7 would be louder..same motor, same exhaust..I know there are differences, but the basics are the same..

I think that the LLY has the pilot injection, so the motor definately sounds quieter. As for the turbo, I have no refercence as to what is louderr, could be the IHI compared to the garett is louder..

Sorry briano - I misread the question last night http://www.dieselplace.com/forum/images/smilies/redface.gif I'll blame it on the beer....
At any rate, the only reasons that I can see for the lly to be quieter than the lb7 with the same exhaust are the cat. converter and the variable vane turbo. I'm not completely convinced that the converter makes that much difference as far as sound goes, but, since the turbo is quite a restriction, that would make quite a difference in percieved sound and exhuast tone....
Just my .02..

minus the cat on both vehicles..I still wonder why the LB7 is louder. I don't know.. I will wait for my buddy to show up with the exhaust I sold him and listen to it. I'll let you know.

thanks

From what I've read on these forums the reason for the LLY being so quiet is the way the VV turbo works. I guess it must cause a lot more backpressure or something than the LB7's turbo which has a wastegate on it. Apparently this is the reason why both our dmax's and the ford powersucks both sounds like jets.

Dumb question Briano... I assume you were setting off codes because the cat was removed.
Did you try the system with the cat on? My understanding is that if you use a cat back system on the LLY it won't cause any problems with codes.

Dumb question Briano... I assume you were setting off codes because the cat was removed.
Did you try the system with the cat on? My understanding is that if you use a cat back system on the LLY it won't cause any problems with codes.
you are correct..removing cat will cause EGR codes, but since I had the complete system I didn't try just the cat back. There is a place that sells a cat back setup from the 4 bolt flange back.

I think the lly is quieter because it has no egr, atleast my c4500 does not and my lly does. I still makes that jet swooshing after a few seconds even with the egr unplugged. Anyone?Anyone?

Can anyone tell me if the LLY with a 4" exhaust or something makes a similar sound to a Powerjoke when the powerjoke is on high idle when the PS has different exhaust? My friend has an 02 Powerjoke with a different muffler on it and when it goes on the stupid automatic high idle it gets this really high pitched ear piercing super fan noise to it. Please tell me an LLY sounds better than that and doesn't get the Powerstroke farting flutter.

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