miacamaro305

hey i was thinking that which muffler is better i have a 80 series but then people have a 40 which one is better for more power?

kfoley

Technically it would be the 40 since it has fewer chambers and it's not a crossflow design. On your car it won't make that much difference power wise, so get the one you think sounds better.

miacamaro305

well i have a 80 series on but i was curios to know if the 40 is better

kfoley

It would be louder, but it would only net a few hp gain. Not really worth it to me unless you want a louder exhaust.

miacamaro305

well noise does matter but a few hp gain is good

AFatHippo

it wouldnt be worth spending the money to me, but if you have plenty to throw around i guess you could..... as far as hp gains, expect maybe a 1 hp gain going from an 80 series to a 40 series. it might sound a little better to you, but still....youre just talking very minor things: 1 hp, a little sound difference. i would just stick with what you have.

Abird4u2nv1

iTrader: (-1)

I have a 40 series on my 89 bird with the exhaust cutoff right out of the muffler, sounds mean, loud and deep. Might give a thin hair more power than a 80 series. The biggest difference is the sound, The 40 series is a loud aggressive sound, whereas the 80 series is a good deep mellow smooth sound.

91GunmetalRS

My 89 Formula I just bought has a 5 speed and when you shift it with a 40 series (its got one) it sounds mean as hell. Either way, they sound good. Both are good choices, the 40s series is more I guess loud and noisy, whereas the 80s series is defined and more deep and mellow. The 80's is much more civilized but it has a better sound I personally think. The 40s series is just really noisy and is extremely loud. Personally I would buy a Hooker Cat-back, I put one on my 91 RS and didn't have any pipes after the muffler, that really sounded good, but in an atuo car it starts to give you a headache because it s too loud, but it is worth it to drive like that for a week or so. By the way Hooker's cat back was like $270 including shipping. Its a good deal.

Sickness91Z28

iTrader: (1)

little sound difference? I disagree with that. A friend of mine had a 40 series installed on his 91 Z28 5.7 and I have an 80 series on mine. There is no comparison on the sound. The 40 series was soooo much more louder. I'm seriously thinking about getting a 40 series now....they sound great....not to sure about hp differences though...but as far as sound goes....it's a huge difference...

2 dope

so if you get a 40 series, and want the dual look you gonna weld another pipe comin out the back to look like the stock dummy duals? Coz i think the 40 series only exits on the driver side

redbird_400

Techincally doesnt one have less chambers because it wont give as much back pressure? I mean... if your engine needs to breath better then you would get the shorter one, but if thats of no matter then you would get the larger one. *srugs* anyone who knows more care to explain better then I can? Im sure some exhaust freak out there can explain it better then me lol. But I dont see any harm in getting one that flows more, but much harm in one that doesnt flow enough.

kfoley

Well I guess this exhaust "freak" wil explain... The 40 series muffler is a 2 chamber muffler whereas the 80 series is a crossflow (meaning exhaust comes in from both sides and flows "across" the other stream) which makes it quieter by dampeneing the sound. It also takes away some power from the extra turbulence from the crossflow. How much power, I'm not sure maybe 5 ponies. On a street car it's not worth it to change from the 80 series to the 40 series just for the power. I mean you lose more than 5 ponies if the weather changes (for carb guys that don't tune their carb to the weather everyday). On a mild drag car it won't matter that much either. We're talking about mildly modified cars here, not weekend warriors and trailered cars, just our daily drivers. Now if you want a different (louder, deeper) tone, I say go ahead and change it, but if it's just for power it's not worth the $60 for 5 or so ponies...

Oh, and the smaller (less restrictive) the muffler, the less backpressure, and backpressure it bad...

Sickness91Z28

iTrader: (1)

this is kind of off the subject....but...I was wondering....is an 80 series flowmaster the same as an American Thunder Catback? I mean....is the tone any different?

kfoley

No they're different. I think the american thunder system is a 50 series or something like that.. Oh, and it's a single inlet/outlet muffler, same as the 40 series.

BrandenCali

Ya no doubt about it, that a 40 series is louder. On one of my Iroc's I had a 40 series with a gutted cat and it was extremely awesome sounding. Real agressive at idle. Then another Iroc of mine I had a Mandrel cat back installed with a car sound hi flow cat with a 80 series cross flow and it is much mellower at idle, and I have no advantage of the dual exhaust look as I had the tail pipes installed where you can't see them, Thats the way I like it.

IROCThe5.7L

The american thunder has an 80 series.

Sickness91Z28

iTrader: (1)

not trying to start any touble or anything..but are you sure? A friend of mine has the 3 inch American Thunder Flowmaster Catback system and he has dual out's.......

25THRSS

The regular 80 series crossflow muffler by itself has a 3 inch inlet and dual 2.5 inch outlets. The 80 series that comes with the american thunder catback has a single 3 inch inlet and dual 3 inch outlets. That is the only difference. The single in/single out system is known as the force II. Here is a pic of the inside of the crossflow 80 series muffler.

http://www.flowmastermufflers.com/cg...ml?id=MEQywLVj

kfoley

I'm not really a flowmaster guy so I wasn't sure....

Thip22

isn't the 80 and 40 series the same except that the 80 is a dual- outlet muffler?

2 dope

are the outlets on the driver side or like the 80 series on each side?

conlinj

iTrader: (3)

I have the 17233(4) 3" American Thunder Cat Back on my car, it has the 80 series muffler and dual split exit (driver/passenger) polished stainless steel tips. I get lots of complements on it

Sickness91Z28

iTrader: (1)

single in, dual out, 2 outlets, one on driver and one on passenger

2 dope

i wonder why Flowmaster doesnt make a 40 series crossflow with the driver/passenger exits or even a 30 series whats up with that? Most of us that like flowmaster want a louder tone like the 40 series without the single side outlets

25THRSS

They do, it's called the 80 series, lol.

2 dope

lol i mean why cant they make one that sounds like a 40 but setup like an 80, i mean how many of you would like a 40 series sounding driver/pass outlet

80 doesnt sound as good as a 40

IROCZTWENTYGR8

iTrader: (1)

They do, they're the same thing. 1 has 2 pipes and that is what changes the sound from the 40 Series.