General Muffler question

[Nima]

My question is about installing a dual inlet and dual outlet mufflers, Flowmaster 50 and 70o series big block in specific. On either side, can you use one of the connections as an inlet and use the other one as an outlet? Basically, I am asking if each side dual inlets (or outlets) have to be both inlet or outlet only? I hope I explained it!
I have on hold for over 30 minutes more than once at Holley's tech phone line!!

[ProjectDD]

It depends on the internals of the muffler. If they are just straight through one side to the other, with perforated tube it wont matter. Some have built in X pipes and depending on the X pipe design, might not flow the best if you don't run them dual in on one side and dual out the other side.

This Jegs muffler wouldn't flow the best if you ran it 1 in and 1 out on each side of the muffler.


Pypes has a straight through design, common on the 70-81 Camaros. Where you can run 1 in and 1 out per side.



So, it's really muffler dependent if you can or shouldn't

[Nima]

Thanks.
It is kind of disappointing that the Flomaster ones (the 50 or 70 big block ones) don't have any specific descriptions on Holley's website. The customer service sucks too, keeping you on hold for such a long time. Also, I have been searching online to see if I can find any info but no luck. I like these mufflers because they are quieter than others.

[ProjectDD]

Originally Posted by Nima

Thanks.
It is kind of disappointing that the Flomaster ones (the 50 or 70 big block ones) don't have any specific descriptions on Holley's website. The customer service sucks too, keeping you on hold for such a long time. Also, I have been searching online to see if I can find any info but no luck. I like these mufflers because they are quieter than others.

The best I can do for you is this photo from their site. If you look down to the right where the 50 series big block muffler is. Looking at the internal of the muffler, it's designed to flow one direction through the case. Flowmasters have their internal baffles which are design to deflect air flow for sound. So they have to be used in the direction intended.

[Getter-Done]

Here's a video that shows the mufflers Cutout.

The mufflers that you have are near the end of the video.

How to Select the Right Flowmaster Muffler -...