Muffler

I have experience with several magnaflow style mufflers over the years. I've used Different trend flow II(got those at exhaust shops), Flowmaster Flow FX, Total flow. All stainless steel straight through construction and I like them, to me I can best describe them as they have somewhat of a glasspack sound without all of the rap and frap like a lot of the glasspacks have and they are quiet in the cab under cruising conditions but get plenty loud when you step on it and wind the engine up. Not to mention they are no restriction to exhaust flow whatsoever.

I've run them on two 2.5" dual to 3" single exhaust systems, one of them being our old dodge van that had this HUGE industrial style muffler that had all sorts of louvers and baffles in it and got plugged up after 20 years. Noticed a pretty big torque and power increase swapping to the straight through magnaflow style muffler and it sounded better as well. Heh, those poor new owners were way over their heads buying that thing.

I've run them on a 2.5" dual with H pipe and REALLY like that system, sounds good but not overly loud and has a really tightly wound-up sound revving to the redline. Maybe that's just the high compression 390 speaking for itself, I don't know.

I've run them on a 3" true dual exhaust with a 500 HP 445 FE and while they sound good I can't hear myself think driving that car and am going to have the system redone in 2.5" for not only noise but fitment issues under the car over the axle as well. The bigger 3" pipes definitely give a lot deeper tone than the smaller 2.5" pipes but HP makes noise and a lot of it.

I have glasspacks on my 99 grand marquis and those don't sound anything like glasspacks do on a non catalytic converter carbureted vehicle. Not loud inside at all and the catalytic converters seem to prevent a lot of the popping and brap and frap sound from them.

I'm running the stock manifold and cats (which is why I said it will take more than a muffler to get the desired sound). I was hoping for a $150 solution but it did little.

Powerman5K wrote

I'm running the stock manifold and cats (which is why I said it will take more than a muffler to get the desired sound). I was hoping for a $150 solution but it did little.

I dont know if you can get a good sound out of the factory log exh manifold?
The van was a 68 Dodge with a slant sex 225 with factory manifolds and glass pack and there was no difference in sound.

Now on the pickup I have always had the EFI manifolds but first on the road was a full system, less cat, and the big replacement muffler with the smaller 81 pipes.
I then went with the 94, little larger pipes, still no cat and welded Thrush and like the sound.
So the muffler dose make a difference just dont know if the EFI manifolds do or not but I would say yes.

The other thing why I went with the 94 system besides the larger pipes is I can go to any parts store and get a replacement system.
If you go to a muffler shop and have them install a non-factory muffler and different pipes if you need to replace any of it what do you do?
Just my .02
Dave ----

Just for the heck of it, take the pipe loose behind the cats and see what it sounds like. If it sounds like an air leak (hissing at higher rpm/throttle, then the cats are restricted.