Need muffler suggestions

[Flyfisen]

351W and I run 2 into 1. Flowmaster delta 50 series truck muffler. Quiet until you drop in the secondary’s.

 

[T-7ToNewOldB]

That one was on my list as well to try. Going to stick with the Hushpower II for a while at this point. Would be nice to be able to try 10 or so to make a choice, but no luck on that. Need some VR program with good speakers or headphones.

 

[T-7ToNewOldB]

The Hushpower II apparently comes in "aggressive" and "moderate" tones. My first was the aggressive one. Trying the moderate tomorrow.


Expect to have a stainless magna flow and one of the Hushpowers IIs for sale in the near future. 400 miles on the magna flow and 20 on the hush power. Will see what I like the most, and post then.

 

[T-7ToNewOldB]

Magnaflow from Duff's first. Too much droning at higher RPM
HP2 (short version). Great idle too loud. Louder idle than the magna flow but quieter at high RPM. Nice popping on deceleration.
HP2 (long version) Same as the short just a little quieter. Still too loud at 70mph, even though engine was sub 3k.
Flowmaster 50 Delta. Perfect! Still pops on deceleration, nice deep idle and good sound under hard acceleration. Quiet (enough) when cruising.

Mission accomplished!

BTW I'll have a magna flow and the (2) HP-2s for sale shortly.

For reference Blueprint 347 with Duff 2:1 exhaust and shorty headers.

 

[rguest3]

2-into1 exhaust with either Flowmaster Super 50 Series or Gibson Superflow. Both have a nice mellow low toned V8 sound.

 

[DirtDonk]

Great you found a good combo T-7. Feels good I bet!
The little bit of popping might have a secondary (or maybe it's the primary) reason other than the muffler design. The two that had more popping on decel could also be indicating they're better flowing as well, which is leaning out your fuel/air mixture.

I've forgotten already if you're running a carb or EFI, but if a carb you may just be running a tad lean. You could "test" this (if you can call this a legit test) by plugging up your PCV valve just temporarily for a short drive. If the popping is reduced or goes away completely, you've probably found that your mixture is a bit lean now. If no change, then maybe it's just that this type of muffler is prone to that effect.
It sounds like you kind of like the popping, so it's not a priority to get rid of. But if it's doing it from being too lean you might as well know it so you can deal with it and make certain that the condition does not cause future problems with the engine.

Paul

 

[bronconut73]

https://classicbroncos.com/forums/showthread.php?t=256591

 

[SteveL]

I have flowmasters on the 66. Sound good but loud. Real good for getting extra attention from the pop-up. On the 72 I went with the borlas. I think the were a couple inches shorter for clearance and all stainless for less $$ than the flowmasters. Nice low sound.

 

[AZ73]

Cheap no name Turbo's seem to be the muff of choice for most. I like the Walker QuietFolw.......Run one on my Samurai and will be putting them on the Bronco this winter if things go as planned.

Tim

Second the Walker. Big but beautiful. Basically an aftermarket version of a mid-80's GM 350-454 Truck. I spoke with the engineer at Walker - MORE than enough air flow capacity for a 347, even at high RPMs.

https://www.youtube.com/watch?v=kRyv9zTyhSo

 

[T-7ToNewOldB]

Paul, ProFlo4 on the truck. Popping starts at 1,500rpm during deceleration. I believe the PoFlo has a setting that cuts fuel partially on deceleration at 1,500 rpm. At least that is what the setting in the program says. Doesn’t really explain exactly what it does.