wcbcruzer

Ok, I got the muffler installed today! Sound clip comparison coming soon...

Overall, I really like it. This setup is just what I was hoping for. I did some freeway tests as well. It's still got the nice deep rumble and with the windows down the sound isn't too different actually. If I drive by a wall it sounds just good, a bit quieter. You can still hear the turbo whistle. From outside, it's got a nice deep rumble but without the higher frequency noises. From inside, it's definitely quieter. I can hear the pulses in my mechanical fuel pressure gauge again, and when I play music I don't have added "bass" from the engine. I love the straight pipe sound, don't get me wrong. It just gets kinda annoying on long trips. The muffler is a good compromise imo. Actually, for the first few hours after I put the muffler on, I was thinking "Oh man, maybe I made a mistake," but now I think it's better. I'm just GLAD that I didn't get the Donaldson muffler that I was thinking about getting instead. Those things are 9-10" round; the MBRP is 6 or 7" round. People say with the Donaldson it sounds like stock. I couldn't see myself going back to that, not to mention the possible drop in hp.

One thing I wasn't sure about was that the guy at the shop put the muffler on with the exhaust flow going INTO the baffles. In other words, like this:



Is that right?

Now with the muffler, I do kinda feel like I may have lost some hp. Could be just me or the fact that it's quieter now. Has anyone dyno'd with/without a MBRP muffler? I'm trying to figure out what's the case...

On one hand, with the 5" exhaust I obviously have more than enough flow. Some hp "may" be lost due to the fact that exhaust gas velocity slows down as it expands in the bigger pipe; hence, having to be pushed out. So even if the muffler adds some restriction it shouldn't matter right? (since the pipe is so big anyway).

On the other hand, what if it's more of a doubling effect. Not only is the pipe bigger, causing slower exhaust emission, but also the muffler contributes negatively with even MORE restriction...?

What do you guys think?

MikeBrei

I had the same question about the inlet when I installed mine. Here is the link to the responses.

https://www.dieseltruckresource.com/...t=mbrp+muffler

mikmaze

louvers forward or back is up to you on how much sound you want taken out as I see it. As you installed, it absorbs more sound, reversed lets more sound through.

wcbcruzer

Actually, I saw your thread and at the time it only had one response, which is what made me think you're supposed to install it with the exhaust flow going against the baffles.

duner

cherry bombs are built this way, and like noted previously you can control the sound somewhat by flipping them around.

Bersaglieri

My truck came with a MBRP 4" system stock. Sounded pretty good. Mine was on with the luvers in the loud position. You can run them either way, but in the quiet way they will really slow down the exhaust.

-Dustin-

01RAMer

I called MBRP when I installed mine, and their responce was the "M" in MBRP goes towards the back. This is the same as having the loover openings pointed towards the back. They told me you could actually install it either way, your option, but with loovers forward there is a little more restriction but it's suppose to be a little quieter. These were actually designed to have the loover openings toward the exhaust outlet (toward the rear).

torkmnstr

I dont remember there being any other way to hang the muffler if flipped? It looks like the hanger will only go in one direction.

tx_2500

Holy crap, those are some huge louvers, mine are tiny in comparison. My FSP muffler is turned backwards as well. I talked to the mfg and he said the louvers are supposed to face foward but that I should turn it around for better sound. Sometimes I miss the straight but it was brutal on long trips. My buddy has a 3rd gen running 5" straights. He rode with me the other day and decided he had to get a muffler put on his.

wcbcruzer

My main concern is that the muffler will get louder over time. Right now the tone is perfect. I called MBRP yesterday and they told me that their 4" mufflers have a fiberglass/steel mesh packing, and their 5" mufflers are just steel mesh. So with my muffler the sound theoretically shouldn't increase with use like the glasspacks; however, I imagine the louvers would get clogged with soot pretty fast. I'm not really worried about any restriction from how the louvers are facing, I figure the 5" exhaust is plenty big.

GUMP

does the flipping of the muffler change the drone rpm?

duner

you're only two clamps and a few beers away from knowing for sure.

purduepurdy

I had to take a few inches of the tailpipe when i did mine, anyone have the this issue. I couldnt even get the tailpipe on the last hanger until i cut some off.

wcbcruzer

Well... Once you clamp the pipes on and drive it around, it's real hard to get them off again. I tried, but I ended up just going to a muffler shop.

wcbcruzer

My tailpipe exits before the factory set rear-most hanger. I don't have a MBRP exhaust though. Just the muffler.