I have read various posts that says changing to a magnaflow, flowmaster or any low restriction exhaust will take away low end power on the hemi's because of no backpressure. Is this true or not? I am still a bit skeptical about changing after reading these posts. Any info will help.

 

I'm far from being an automotive expert, but I've read that when you change the piping from a single to dual, or vice versa, you can lose back pressure. That was posted on a thread about the 4.7's. So, I can't be for sure about the Hemi's. I can't believe that a higher flowing muffler will do any harm. Anything that makes your engine breath easier should only be a benefit.

My advice: check with a dedicated muffler shop or certified automotive technician.....that you trust.

John

 

There's a difference between a bigger or dual pipes and less restrictive muffler. A less restrictive muffler will allow gasses to flow faster at all speeds, whereas a larger pipe will effectively slow the gasses down at lower speeds, causing a loss of low-end power. I'm not going to post my reasoning yet again, but if you search recent exhaust threads (flowmaster) it's out there.

 

It was still on the first page even. Give this a read: https://dodgeforum.com/m_192213/tm.htm

 

For what it's worth, I replaced the muffler on my 3.7, not added duals or changed the pipe in any way, just new flowmaster. The sound is very sweet; no loss of power. It seems I may have picked up some power, but that also may be just because it sounds soooooo nice!