Right now i have a 3" downpipe with a 3" in/out magnaflow. I was wandering if there would be any benifit to changing muffler to 4" in/out magnaflow. I want a little more sound so this help, how about performance gains?

 

nobody has ant thoughts on this

 

A lot of turbo guys put on OEM duramax diesel exhaust. I believe it is 4" from start to finish. You could always cut the factory muffler off it and weld on a magnaflow.

 

I put a 3" electric cutout right on the end of the down pipe, and hooked into my catback from there. I think it just barely spools a little bit faster. You can hear the turbo a lot more than with it closed, it sounds awsome. I have had a couple of people not race me when I open it.

 

While most would find it ridiculous to spend so much money for what may be considered too quite an exhaust system for most performance enthusiasts out there, I’m actually considering purchasing a pair of take-off Corvette NPP (Bi-Mode) mufflers and installing them with a "NPP in a Box" wireless vacuum control system that allows you to install and operate them. Of course I would have to cut the pipes of the mufflers and weld them into my current pipes, but after years putting up with a fairly loud exhaust, I figured it would be nice to have the option of running it in quite mode on the highway. By default, it would always start up in loud mode and is most likely where I would leave it at most times due to the factory mufflers not being that noisy even in loud mode, but it sure would be nice to save getting a headache on a several hundred mile trip. Of course B&B has a set that are loud and louder, but that would defeat the purpose for me. Maybe I’m just getting old or just can’t leave well enough alone.

 

Can't you see straight through the M'flow? If you can see straight through it, there can't be much difference between it and a straight pipe. If it's 3" on the front side and 3" on the back side, what's the diff? I can't see any performance gains, but I can see a little meaner sound with the 4".

 

Good point.

OP- How many psi/rwhp are you running? Is it cranked up high enough that better exhaust will affect it, or will you just be wasting money?

 

Don't do it! The NPP muffs are a great idea poorly applied. When I first had mine, I was convinced that this was the be all, end all, exhaust system. Quiet when commanded, yet loud with the push of a button. I was scheming to find a way to adapt them to my truck. Now they're falling apart. Sounds like a tin can with gravel in it. Apparently, they can be fixed, but fail again. I'm done with them. Some things just shouldn't break....mufflers aren't on my list of things to fool with.

 

Thanks for the input, as I don't want to add problems. I do imagine the additional tailpipe length would tone down the B&B's or by keeping the Dynatech Bullets, it may keep it a little more quite, however the B&B's are a little too pricey for an experiment.