Testing different muffler combinations on my LS swapped 96 Impala
LSX B15 376 (basically a forged LSA with LS3 heads and an LS7 cam)
LT headers
3" true dual/X pipe
LSA @ 16.5 PSI, 700whp (boost is bypassed when N revving so revving sounds a lot tamer than when really getting into it).
Wish I could have been more scientific/consistent with the testing, but the work conditions suck LOL. My goal was to achieve a fairly quiet system that could be cruised long distance but with great tone.. Very hard to achieve in a car like this, I think because of the 3" exhaust and sheer length of the exhaust. it creates a lot of resonance in the piping and I found that some mufflers which were tolerable on shorter wheelbase cars or Y pipe cars just had too much booming/echoing/bassy sound on this car.
Few things to be aware of when listening.
1) wish I could have revved it higher, but with the tests I was doing in my driveway it was getting late and I didn't want to piss the neighbors off too much so I was a little easy on some of the revs
2) many of the driveway videos, the muffs weren't clamped so I noticed that the sound got a little less aggressive on the ones I chose to use after I clamped/welded them presumably because there wasn't sound leaking out around the muff inlet after that.
3)some of the later videos were at different stages of tuning/HP so there are some slight differences there.
Since you can't always get a feel on drone/volume from videos, here is my opinion on each combo:
1) SLP LM1- Wicked tone idling, wicked tone WOT but everything in between sounds like open headers- loud, echoing, sloppy booming drone like a pickup truck with a broken H pipe. Way too much noise inside and outside of car, although I've heard this same setup on stock LS1 F bodies and they sound great but they didn't have like 6 feet of 3" piping resonating lol. Still love to hear what this combo would sound like with tailpipes focusing the sound and maybe the dynomax race muffs somewhere in there.
2) Dynmoax Ultra Flow SS- kind of a cool sound at idle. Pretty loud, louder than magnaflows and probably flow master 40's as well. Revving had a tinny buzz in the sound (sorry, it was more present when revving it higher than the video showed). Think they may have sounded good if the buzz was cut with a pre muff/resonator but too much interior noise for me.
3) Flowmaster 40's- .Not much to say here. Personally I love the flow master tone, some hate it. Not as loud as I thought they would be, but still more resonance/drone inside and around the car than I wanted.
4) Borla Pro XS- Quietest overall, great idle tone, not a lot of resonance inside or around car. Little tinny sounding when revving but cleaned up real nice with the addition of the dynomax race muffs just before them
5) Borla Pro XS w/ Dynomax race muffs- really nice idle tone, very mild cruising around and will probably be better with tailpipes (I currently have turndowns only). The race muff welded before the muff didn't seem to affect the volume much except for WOT where it cut back some of the tinny/raspy note. Only gripe with this setup is it's almost TOO quiet at WOT. They have kind of a weird tone at WOT that almost doesn't sound like LS exhaust note, kind of like a V10 or something but it's interesting. my experience with any packed muff is they will break in and get louder over time so I'm curious to see how that goes.
6) Various magnaflow setups- the magnaflow bullets have very low interior volume in proportion to the exterior WOT note. The original 3" bullets through ETC resonators was just way too loud for me cruising around. The vibrant mini bullets I welded in up front cut down part throttle a bit and made it nicer to cruise but the ideal setup for me was the 5" magnaflow bullet with the vibrant mini bullets up front and ETC resonators out back. really tame cruising around town but nice tone. WOT still had some great volume. This setup overall was about the same volume as the Borla Pro XS/Dynomax combo part throttle but much louder at WOT. Only thing I didn't like about it was the vibrant mini bullets made some weird tinny/ticking sounds at idle probably from packing coming loose, the idle was almost too bassy where it buzzed things like a subwoofer and masked the tone out the tailpipes. WOT had a very cherry bomb glasspack like sound (which makes sense, since a magnaflow bullet is just a 'glasspack' ). Still great but the Borla combo has better tones IMO, despite not having the WOT volume.
Spintech 3000xl- cool tone at WOT/part throttle but way too much interior noise and really sloppy/broken exhaust sound at idle/ very light throttle. Maybe better with tailpipes?
Will get more video up of the borla setup once I weld up tailpipes and will probably try some new stuff too. This quest is not over lol
#LSX #LS3 #LSA #impalass #impala #lsswap #exhaust #magnaflow #dynomax #borla #flowmaster #exhaustsound
