I know my flowmaster 40 series sounds good, and it's actually a truck muffler with 3" inlet and dual 2.x" outlets on the driver's side.

I heard the slp loudmouth a few times last night at Muncie and hated it, way to loud, and to me it just doesn't sound good at all

 

I'll let you guys know how the 40 series sounds after I get it installed tomorrow. I'm also looking forward to getting the exhaust leaks fixed. I know it's robbing a lot of power right now. So between that and the muffler, it's going to be pretty substancial!

Steve

 

I think you'll be disapointed with the sound. I've heard several Flowmasters on 3rd and 4th gens and I think they sound kind of raspy and they cackle/pop too much on deceleration. I love the sound of my 2OTL. No cackle, no pops, just a deep rumble.

Let us know how ya like it though.

Mike

 

The 20TL is most likely what's on the car right now, correct?

Yeah it sucks, we love the sound. At track events, people have come up to me at the end of the day to tell me that they let me go by just to hear the car (like they had to let me by), but the fact is that it's just too restrictive for the 396. Or so we think. I mean, worst case senario, if it sounds like crap, doesn't pick up anything on the butt dyno and the real dyno, then we just put the old muffler back on.

Anyway, I'll post here as soon as I get home tomorrow morning. Wish me luck!

Steve

 

Borla all the way

 

Wow, I find it really hard to believe that that SLP 2OTL muffler cost you 20 rearwheel horsepower after you dropped it on a car only making 375 to the wheels. Your 2OTL almost certainly has the "ring of silence" installed in it which would definitely hurt flow and make the car noticeably quieter (especially since many '97's with this exhaust has this little restrictor plate put in it). Otherwise, 2OTL flows about as good as you'll get for any cat-back (and gives up hardly anything to a cutout; even on a car making as much power as yours). I'd just recommend keeping that system and removing that ring of silence/restrictor plate.

Otherwise, I do personally think Flowmaster (any series) sounds great on the LT1 (although it has been proven to not flow nearly as good as the 2OTL on cars making good power like yours). And whoever said Flowmaster was raspy on 4th gens, that is only without cats from my experience in person. With cats in there, the tone is just a classic muscle car rumble and nothing sound deeper to me...

 

link to this "proof"?

 

I had the TOL on my hawk. It sounded great but it was a piece of crap. It broke at the welds so i replaced it. I put in a Dynomax Racemagnum. 3inch in 3inch out. Straight thru design and the sound is great. I dont think they make the racemagnums anymore but im sure they got something similiar.
I give a thumbs down for the flowmasters. I hate the way they sound on an LT1.

 

That would be the Ultraflow.

 

so, what I see from reading everyone's response on this is that flowmaster's suck both for flow and sound? And that a lot of people enjoy the SLP 20TL? What kind of sound does the flowmaster make that you don't like? Too muffled? not loud enough? Or just that they don't flow as well as SLP's offering? I just want to know why flowmaster's get such a bad reputation from a lot of people before I go buy one.

 

Actually they sound quite amazing with out headers... very throaty with no rasp or pop, but with headers the get kinda raspy and I have heard they dont flow as well as some of the competitors, borla, hooker, gmmg, slp, etc.... Then again I have almost no proof about the flow numbers, only speculation and hearsay...

 

A buddy of mine has a 95 TA with a flowmaster system, and I think hooker headers. Anyway, it sounds pretty good, but not as good as the LT1 that is in my Fiero. I have a full 2.5" system, cat, no muffler and resonated tips. The tips are what make it sound so good. It has a slight burble to it. Sounds quite exostic actually. What im getting at is, if you use a muffler that flows well, but is to loud, stick some resoated tips on it. If you want to see a pic of my exhaust, go to my website, theres a pic of it there.

 

i made 500rwhp on my flowmaster
stock shortblock and 6psi threw the strim

 

Ah the classic debate...

Let's clear something up...the only way to make 20HP from a muffler swap is if you swap out the old muffler and replace it with: NOTHING! Thats right, if you are worried about flow, go with a cutout or the dynomax ultra flo welded. They are cheap, and dynomax on their website offers proof that they flow the best and support the most HP.

The ultra flo's for example each support 1000HP, and can flow in excess of 2200cfm I believe is the reported #. Yes indeed Flowmaster was fairly low on this chart. However, so were some of those other brands that supposedly put flowmaster to shame.

Another note about bashing Flowmasters. If you even bother to look on their website, you'll see that they have redesigned the 40 series. A 2nd generation so to speak. It would be wise if people start referring to flowmaster in past and present 40 series, because these new ones are supposed to be that AMAZING flowmaster sound, which I know any muscle car ethusiast loves, along with dyno proven increased HP.

As well, it would then be good to note that 1 vs. 2 chamber perform differently (I saw someone posted that they had 1-chambers on here earlier)...

And lastly there is a lot more to an exhaust than a muffler. Mandrel bending, pipe diameter, header choice, etc....Don't overlook crappy welding, and all that for the sake of a brand name.

Hope this helps.

 

so its basically a matter of what one's ear is drawn to, i guess. I had a buddy with a 1994 Z28 with long tubes, offroad 3' ypipe (no cat) and a flowmaster 3" catback with dual outlets. I absolutely love the sound it makes. I have another friend with a 1971 camaro with a 327 small block race engine running a 2 and 1/2 inch flowmaster exhaust system, i can say that the 94 is a little louder than the 71, but it doesn't get raspy or rattle around. I have to think about if I really want to spend the money to get a GMMG cat back.