My 89 Bronco with the stock cat was still quiet with no muffler and 2-1/4" pipes. My 86 F150 and my 90 Bronco, both with aftermarket cats were obnoxious with no muffler. I put a turbo on the 86 and it was really quiet. The cat fell off and I've yet to replace it because the truck barely gets driven. So I have a straight pipe and it's still quiet.

So many variables...

 

Summit Street and Strip is nearly identical to the Flowmaster 40 also, and costs less than the Thrush copy does.

 

Just put a cat on it and add a large body Dynomax super turbo.. it produces a good balance between full throttle noise and light throttle rumble.

 

All I'll ever put on my vehicles is Summit brand mufflers. On ALL the vehicles in my sig I have summit brand mufflers and they rock. Absolutely no drone at all. The Mustang and the '84 have long tubes, true duals, and Summit mufflers. My Bronco (my favorite sounding one) has shorty headers, 2.5 inch y-pipe that steps up to 3 inch where both tubes meet up, single 3 inch Summit muffler and it sounds amazing but I sadly don't have a sound clip of it.
Here's the '84 though to give you an idle sound clip

Here's the Mustang

I think somewhere I have a video of the car right after I got the exhaust done where I revved it up. I can try to dig it up if you wanna hear it

 

I know this is an old thread, but it came up in my search, and your comments here Conanski hit the nail right on the head for me. I had no idea this was going to be such an issue...lol. Learning my lessons the hard way, as usual.
I started out with a Flowmaster 40 series (single 3" in, dual 2.5" out) with turn-downs under the box, and the thing was so loud I couldn't even drive it. I swapped in a Flowmaster 50 series Delta Flow muffler mainly due to the ease of install...all dimensions were the same except the length, and it's better, but still too loud, and too much drone in the cab.

Would adding a high flow CAT, and full tail pipes settle it down much, or is the issue still going to be there due to the Flowmaster muffler?

I'm going to get a muffler shop to do the finish work for me, but I'm trying to get the bugs ironed out first so that I can figure out what I need/want.

I want some exhaust rumble, but without the drone/reverb in the cab, if such a thing is even possible.

 

A high flow cat will mellow it out a bit. Your biggest problem is the lack of having tail pipes. And I suggest switching to Dynomax or Magnaflow or something similar. Anything besides Noisemaster. I'm running 3 inch single Dynomax on my new 94 and love it.

 

Just get it out from under the truck. That will help 90 percent of the cab drone.

When my muffler died and I had to drive home from work with just the cats dumping under the truck, the reverberation in the cab was annoying. But, just putting a piece of pipe in place of the muffler and running the stock tailpipe to the stock location made it sound like nothing changed from the stock exhaust inside the cab.

 

Thanks for the replies guys, much appreciated. I've been searching this morning, and I see the Dynomax Super Turbo mufflers are on the quieter side? I'd like a little bit of a rumble, but still livable in the cab. I guess I'm figuring out that I don't like the noise as much as I thought I would...lol.

And yes, I will be installing tail pipe(s). I was just trying to get the basics installed at home so I can drive it to a muffler shop, but I didn't realize the Flowmasters and dumps were going to be SO LOUD...lol.

 

I have Dynomax Ultraflo. Its aggressive but not extra loud. Yes their Superturbo is great but pretty mellow.

 

Thanks for the replies. I'm going to get the header bolts and gaskets changed out first, and then run it in to an exhaust shop and see what they can do for me.

 

Gentlemen,

Thanks for the replies. Just got the truck out of the exhaust shop with full 2.25" duals and stainless Magnaflows with an H-Pipe. It is almost too quiet now...lol, but it sounds good. I'm happy with it. Just kidding on the too-quiet part...it still has a very nice rumble to it, but is still nice and calm in the cab. I could handle more exhaust noise, but with the trade-off of having more droning in the cab, I chose the lesser of the two evils. I want to drive this thing, and I couldn't the way it was before.

Thanks again.

 

Personally, I really like the sound of the Magnaflow's. I think they have just enough rumble when you open up the throttle, but still quiet enough to not make conversations in the cab inaudible...