Muffler or delete

[rlawrence110]

I just want to know if a muffler really hurts performance or if it doesn't really make a difference. Thanks in advance.

[late_99_PSD]

What truck?

The sound is good enough reason to delete the muffler, but many people notice a MPG gain when they do a straigt pipe setup.

[mazsecond]

The stock muffler just puts more back pressure on the engine, which with a turbocharged engine the less back pressure the better. Faster turbo spool up, better response, better MPG, and a little more HP and TQ on the low end. Plus, you can't beat the sound of a straight piped 6.0!!!

[jse51599]

On my L99 auto, I did a delete first and it wasn't too loud at first. But, the constant 'drone' of the exhaust on the highway was a bit much for me. I ended up w/ a Walker BTM muffler that is a straight thru design, but cancels out some of the noise. To me, I don't think there is much diff between straight pipe, or muff w/ straight thru design other than noise level. W/ the BTM, I noticed a small gain in mpg's. (I also did the 6637 mod at the same time, which probably helps too.) As w/ anything else, everyone and every truck is diff, so I would suggest a straight pipe first since it's cheaper than a muffler; if you don't like it then spend the money on a muffler. Just my opinion tho.