Thoughts on running dual thrush chambered mufflers 2.5in/out vortec 454

[OutlawDrifter]

The Thrush 2 chamber (flowmaster 40 knockoffs) I ran droned for maybe the first 400-500 miles, and then completely stopped, leaving only the trademark/signature blub-blub-blub-blub-blub sound that 2 chamber mufflers are known for. They do a very nice job of cancelling out raspy high pitched frequencies. They sounded good, just didn't live very long. Mine were duals with corner exits at the bumper.

good to know, i like the flowmaster sound. i just don't care for it in the cab! i've been very happy with my ultraflows on the last couple of pickups, they have a sound all their own, you get the deep sound of a big glasspack without the pop and crackle.

 

[Jorge6.5]

how about running an H pipe a foot or so before the mufflers? I figure it's the best route to go to balance the exhaust without cutting up the existing exhaust pipe.

Thanks for your input

 

[CustomMetalWorks]

I am currently running (how I bought the truck...changing soon) a single in/out Flowmaster ko 10 series. It's definitely not how I would have done it. I hollowed out the cats for now due to them strangling the big block. When I get the long tubes and mufflers it'll be true 3" stainless with H pipe and 45'd out the ass end. I have been a loyal Flowmaster customer for years (love the super 44 and super 10) but think I'm gonna give the spintech's a whirl. I like the design, no dead stops when entering and the design of the baffles causing a "scavenge" effect. I always spray a coating on my mufflers as I live in The salt best Midwest. I'm new to the forums but I'll try to post a sound clip of the single 10 series with stock manifolds and hollow cats.

You must be registered for see images attach

 

[OutlawDrifter]

you want the H closer to the manifolds/headers. the problem with the stock exhaust routing is it puts the H further away from the driver's side than the passenger side. but any balance pipe is better than no balance pipe.

custommetalworks, dual 3" is way overkill for a low rpm big block, you'd have better power down low and in the mid range with dual 2.5" pipes.

 

[Jorge6.5]

Well seems like I'll be going deeper into my exhaust. The current cat or cats are starting to blow out. The other day a nice chunk of honeycomb came out of the exhaust.

Would I be alright going with a pair of those thunderbolt cats, 3"in/out? Then going to 2.5" exhaust after that? If I'm gonna be swapping the cats, should be a good opportunity to plump in an h pipe pre cats.

 

[OutlawDrifter]

yes on the thunderbolt cats.

just food for thought...if you're not stuck on dual exhaust a single 3.5" will flow every bit of what you need. it also helps reduce your cost. if you go single the singe route, use a good quality y-merge like the flowmaster unit.

my 6.0l camaro has a single 3" exhaust. it has a cutout before the axle and only picks up 10hp with it open! this is on a 425rwhp car. so that's over 500hp at the crank at a modest 18% drivetrain loss.

 

[Jorge6.5]

I'm actually considering a catalytic converter delete and using spark plug non foulers. But I wouldn't mind running cats cause I know it will be loud without them

 

[beardeddummy]

I have side exit much like you are referring to on my 454 and I don't think it is too loud for cruising but you can tell it isn't stock. I'm running a borla dual in dual out muffler (2.75" out I think) and headers.

Just curious how's the borla sound

 

[Christian Steffen]

Just curious how's the borla sound

I think it sounds good. I still intend to get a video and some pictures with measurements, I've just been super busy lately.

Christian

 

[65nightmare]

I'm actually considering a catalytic converter delete and using spark plug non foulers. But I wouldn't mind running cats cause I know it will be loud without them

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Idk if this will work but here is the sound clip you may need speakers or headphones my phone suck at recording sound.