Just got back from the exhaust shop. First of all let me say I feel like an idiot. When I got to the shop I thought my truck had a 4" system on it. Imagine my surprise when they corrected me and said it was 5". I had them go ahead with removing the muffler. After climbling around my truck (and a few burns), I have confirmed that this is my current set-up:

-AFE Dry Intake
-4" downpipe
-5" exhaust: No cat, no muffler, no nothin

My question is this: My previous truck (chevy 350 gasoline) had backpressure problems with straight-pipes. With no other performance upgrades, will having 5" straight-pipes on a 6.0 cause any problems or should I put the muffler back on? Thanks!

 

Leave the muffler off, you don't need it unless the cops say it's too loud.

 

The turbo gives you all the backpressure you need. Im runnin 5in in front of the rear tire and it is ridiculous loud.

 

Thanks guys. I figured the turbo would fill the pipes up fairly well, but I like to hear somone else say it. And yes, it is loud. I dropped my wife off at her office after lunch. She described it as "disruptively loud" and all I could do is smile.

 

Yes turbo provides all the backpressure you need. In fact in most states the turbo can be considered a "muffler" as well. I know it's that way in NY where I live.

Are you sure you have a 4" downpipe? It's kind of a special order thing only with 6.0's. 3.5" is the standard, 4" is tough to fit, but can be done.

 

Seriously!?! After the way you got SPANKED about the OEM down tube!?! The special order part is when you put the "X" in the block for a FIVE inch turbo back system. Quit listening to "they" and "them", you're going to get into trouble.

 

thanks guys,, glad to finally hear someone say a 5" is ok.. all i've been hearing is a 4" is all you need. sometimes its not what you need,, its what you want... good post.

 

Easy fellas. Thanks for all the input. Yeah its a 4" DP and it sure as hell is a TIGHT fit.

 

Tell me which kit comes with a 4" downpipe... I know of two companies that actually make and sell them. None of the MBRP kits come with it, they're all 3.5". You can ORDER it though, but most people don't even know about it. 5" isn't anything special order. You can either get 4 or 5. Nothing special about it. You can get 4" turbo backs for $265 and 5" for $295. Without specifically asking for it, you're not going to get a 4" downpipe. I got "spanked"? Interesting.

---AutoMerged DoublePost---

Not many people need a 5" exhaust at all, and 4" is all you need, but it is cool to say you have a 5" It certainly wont hurt anything. I have heard of a few being REALLY close to the spare tire, but I suppose its all how you line up the exhaust.

 

[QUOTE=Mdub707;595164]Tell me which kit comes with a 4" downpipe... I called MBRP, and the nice lady told me that p/n S6224PLM at $599 is the 4"/5". SPANKED!I know of two companies that actually make and sell them. None of the MBRP kits come with it, they're all 3.5". You should have called them like I didYou can ORDER it though, but most people don't even know about it. 5" isn't anything special order. You can either get 4 or 5. Nothing special about it. You can get 4" turbo backs for $265 and 5" for $295. Without specifically asking for it, you're not going to get a 4" downpipe. I got "spanked"? Interesting. The OEM down tube is 3" NOT 3.5"= SPANKED
[color=grey][size=-2]