Flowmasters???

tipp33 · December 28, 2003

Will I gain any performance or power by getting flowmasters? I am going to get 40 series, and go with 1 in 2 out.

03Bowtie · December 28, 2003

you will probably gain up to 10hp if you go with just a muffler and not a cat-back system. There's a lot of guys on here that like Flowmaster. I personally don't. The 40 series is their loudest one, so if you are ok with quite a bit of interior resonance in the cab, then you will like it. It sounds good outside the vehicle, but makes the cab a lot louder as well. There's also Magnaflow, Dynomax, Borla, Gibson, and some others you should consider. A lot of guys on here like Magnaflow. I'm doing my truck this week. Going with a Magnaflow, or a Gibson. Haven't decided yet. Good luck with whatever you get, but I would ask your muffler shop their opinions on what you plan to get. Tell them what you are really after, and if they are honest, they'll tell you if the 40 series is the right one for you.

TarheelZ · December 28, 2003

I have the FM 40 (non-deltaflow version) on my ZR2 and it is true that you will have more interior resonance. Any power gains will probably not be very noticeable, depending on whether you also have an aftermarket, free-flowing intake system, and on the size and type of pipes used after the muffler. You'll probably love the sound of the FM 40, though (at least from the outside)!

Good luck!

badass96z71 · December 29, 2003

On my '96 I have a fm 40, I had the guy at the muffler shop combine my 'dual 2.25's into one 3" after the cats and turn it down right after the muffler, it exits just befor my rear end under the truck. Sounds awesome I don't think the ineterior noise is too bad, but hell over the super swampers and the stereo who can really tell. I also noticed a significant difference in performance.

k1500chevy97 · December 29, 2003

The best thing besdies the performance will be the sound

J-rod · December 29, 2003

FM 40's here too (non-DeltaFlow as well). I *LOVE* the sound and with mine exiting at the rear, it's not too loud in the cab. Don't get me wrong, you can definitely hear it (which I wanted to), but you can still carry on a conversation, etc just as you would before. While I'm sure there were a few ponies freed up by the exhaust, it wasn't anything you could really feel in the seat of your pants, but I have gotten numerous compliments on how good it sounds!

Ideeho · December 29, 2003

Don't brush aside those manufacturers that lack massive advertising budgets... I went with Goerlichs Xcelerator muffler and twins out the sides and couldn't be happier with my choice, awesome product, this after considering my experience with Gibsons on two trucks and laughing the price of Borlas and Corsas out of the picture. Good luck.

razor · January 1, 2004

i have the "50"series,so its a "Bit"quieter(at least that what they told me ).it rumbles so nice.people often ask me what type of muffler they are.and asked how do they sound inside(if its intrusive).it sounds soooo mellow,buts thats just me(IMHO) .but i can still hear people talking and i still play the radio.but you cant hear it at crusing speed (like on a highway)Only at innitial take off or going up a hill,grade or entrance ramp

vortec350 · January 2, 2004

I have had flowmaster 1chambers,2 chambers,3chambers,magnaflows and I have finally found the product that satisfies me,I just got 2 Borla XR1 sportsman 12 inch mufflers and I love the sound of them.They have the Borla tone like on the Z28's with a closed plate.I have wanted this sound forever and now I finally got them and will stay with Borla.I liked my magnaflows I had much better than the flowmasters but I like the Borla better than the maganflows.Its the tone they have that I love to hear.Its hard to explain what they sound like without a soundclip or acually being next to my truck.

Cool Zr2 · January 2, 2004

A guy in town dynoed his 8.1 and then put a flowmaster 40 on it and dynoed it again and it showed zero results. I forget the results, its been awhile, all I remember is laughing at the guy cuz he was certian he got 20 hp cuz he could "feel it in his seat".

You guys should know that a muffler isn't going to gain you hp because the cat(s) is/are the most restrictive point in the exhaust, so if you free up the exhaust behind the cat, the motor to the cat(s) is/are still going to have the same environment.

Get a high flow cat(s) or remove the cat(s) for good and Then you will really see some gains.

sierriously · January 2, 2004

I put a 40 series in place of the stock muffler. I still have the same pipes all around and same side exit. The big resonance inside the cab is around 1800-2100 rpm, usually just before shift on strong accelerations. At first this was annoying because this was the only time you heard it, and it was pretty loud. Seemed like too much contrast. But now I have either gotten used to it and really like it, or it took some breaking in time and smoothed out the difference.

Either way, I would talk to your muffler man. I told mine I had a cherry bomb glasspack and a y-pipe on my '94 and that was too loud for this truck. Don't expect to "feel" the performance gains. I haven't noticed any more miles per gallon, either. Do it for the purr, it does sound really nice outside the truck.