5" Versus 4" Exhaust

[mconstable]

Hello all, I have MBRP's 5" on my truck and want it quieter... had a previous thread on this... Mark Craig suggested to add a second muffler...

Question is...

Would a single muffler 4" be louder or quieter than a 2-muffler 5"?

Thanks... Michael

 

[Matt400]

I had a 5" system with Donaldson's most quiet muffler- the "Silent Partner" It droned and was far more loud than stock than I wanted.

Per Donaldson's recommendations (for noise improvement) I changed it to 4" system and a free flow 51" muffler. Huge noise reduction that I believe mostly came from going back to 4". The Silent Partner was also 51".