Flowmaster on 454

[Zacko]

I'm considering the Flowmaster set-up for my 98 K2500 with a 454. I don't want it too loud but am looking for a little performance gain. Anybody have any experience with this engine and flowmaster?

[454ss]

I had the big block series flowmaster on a 96 I had, it sounded good when you got on it, but it wasn't loud at all.

[blown68ssrs]

I have two 50 series Flowmasters with 3" pipes and an x-over on my Pro-Street Camaro. It rattles windows.

[BigBlue02HD]

I had a 95 K3500 single wheel with a 454 and I installed a 2chamber 40 series flowmaster on it (3" inlet/3" outlet) on the stock tailpipe first with the cat., it sounded pretty good (probably what your lookin for), but I still wanted it louder so I ended up taking the cat. converter off and that really woke it up alot. I ended up running 3" duals outta that muffler with a custom Y after the muffler and straight out under the rear bumper. Duals under the bumper took away the interior resonance, but equalled out the sound outside the truck. Really sounded good. Good luck.

[severed ties]

if you want it to sound good but dont want it loud, run dual pipes from your headers to an X-pipe and put 2 40 series flows 6 inches past the x-pipe and turn them down in front of the axle. no cats. it will be quiet at low rpms but it will turn heads at higher rpms. the 3inch pipes are ideal for flows because they allow for just the right amount of air flow to produce a deap throuty sound. if you want it to sound really mean run a single in dual out 3" dia. without cats.

[Zacko]

if you want it to sound good but dont want it loud, run dual pipes from your headers to an X-pipe and put 2 40 series flows 6 inches past the x-pipe and turn them down in front of the axle. no cats. it will be quiet at low rpms but it will turn heads at higher rpms. the 3inch pipes are ideal for flows because they allow for just the right amount of air flow to produce a deap throuty sound. if you want it to sound really mean run a single in dual out 3" dia. without cats.

Unfortunatley the local emission gestapo frowns on removing cats or they would have been gone in a flash.
I think the Flowmaster Big Block 50 series will fill the bill. If you go to the flowmaster website they have some great sound files from several cars that give you a good idea what things will sound like. Now I just needs to wait to get my taxes back to pony up the nearly $400 for the system.

[ksstang]

I'd say go with a 40 series Flowmaster... It will be decently loud at WOT... but not too terribly loud at idle.

Kyle

[GregM]

If you want it loud with a good tone, have you thought about Dynomax bullet mufflers? I put a single 3" bullet on my 5.3 truck and split the tailpipes into duals. It sounds really good; similar to my friends truck who runs a 40 series Flowmaster but with a cleaner tone.


GregM

[heavychevy454ss]

I'm running a single 40 series 3" in/dual 2.5" out with no cat or tailpipes. It will rattle your brains. I've had people that thought I had open headers when they hear me get down on it.
I think tailpipes will quieten it down considerably.

[LikeaRock14]

Here ya go

2000 C/K 3500 454. Flowmatser 70 Series, 3" Single side exit w/ 3.5" chrome tip

Revs in Park
Slight Rev, take off
http://web.utk.edu/~deldridg/LikeaRock/redcruiseby.wav
Hard Downshift into 1st

It's much smoother, and also louder in person. At low rpm's it's DEEEEEEP without the drone

I went with the 70 series since we tow a 34 ft 5th wheel every weekend from March-October, and going on 2 hr drives every Saturday, and sometimes 4-6 hour tows, resonance wasn't an option. When towing the trrailer it resonates more in the cab, but that was expected. It's a bit quiet for my tastes nowadays though, so I'm planning on either an 18" Magnaflow or a Spin Tech Truck/Tv muffler. One reason I'd like to go with the Magnaflow is because it would have slightly lower resonance levels than the Flowmaster at cruise speeds, but should be deeper and louder under normal driving conditions. The Spin Tech is what I would really like to go with, yet chambered mufflers produce drone, so with a chambered muffler I'd have to go with a larger sized model. I'm still debating what I want to do though. I've got another couple months for sure before I finally git er' done (been putting it off for 6 months or so )

Although the 70 MIGHT be a bit quiet for what you want, the overall sound couldn't get any better IMHO. And with a 70, you don't sound like every truck out there

[Butch 02 Denali]

I run a 40 Series big block Flowmaster, 3" in, 3" out on my 1990 454 Silverado. Not too loud, but I have the stock cat and that really quiets it down. With a 3" tailpipe and no tip it's allot quieter than when I had the 3" pipe going into a 4"x 18' tip. It rusted out so I replaced it with 3" pipe. Going to put another 4" tip on, it sounds so much better plowing with the DEEP sound!

[BFEkid]

go with 40's it will sound great