i am looking through my camaro catalog and i saw something that stood out to me. a flowmaster 40 series muffler. it says it makes a deeper more powerful exhaust note. but my real questions are... the dimensions it gives for the muffler are several inches smaller than the stocker, so will it fit? will it mess up where my dual exhausts exits under the bumper? and also has anyone done this upgrae? there is a 3.9 mustang v6 at my school with the flowmaster 40 series exhaust and i thougt for sure he did an engine swap, it sounded that good.

 

Flowmasters sound AWESOME.

At idle, that is.

Once you get to 4000 rpm, they sounds HORRIBLE, IMO.

 

you can put a 40 series on your car but yes, it will mess up where your dual exhaust comes out of the car unless you have some custom piping made to fit. my friend has flowmasters on his 3.8 mustang and it does sound pretty good. like doward said, they do sound kind funny at higher rpms on v6s. i have the 80 series on my v6 and i like it at low rpms and have adjusted to the sounds at high rpms.

 

i was also looking at the 80 series, just because it has larger dimensions and i think it will fit more like the stocker. what size do i need to order, im thinking the 3" single inlet/2-1/2" dual outlet 5"x 10"x 23" or the 2-1/2" single inlet/ dual outlet 4" x 9.73" x 21"... thanks guys

 

They sound great as long as you don't go crazy on your pipe size.

To large of a pipe and they sound like crap. Pipe size from the muffler to the tip should be 1.75 inch. 2 inch should be the largest you go. These engine don't produce a crap load of back presure. In fact if you go to large, over 2 inch IMO, you will lose power.

To large of a pipe no matter what muffler you use will cause such a large drop in back presure that the exhaust gases will slow down and the pulse will not be able to help pull the next exhuast pulse out.

Also don't forget that a small amount back presure helps cool the exhaust valves whitch helps keep combustion chamber temps under controll during sustained engine loads. Open headers are great for short drag races, but not for maintaining high speeds.

On the flowmaster website they have a article that talks about what type of pipe size to use. It's mostly aimed at SBC V8's and BB V8's, but with common sense you can get an idea of what pipe size to use.

 

the 40 WILL RESONATE BADLY! even with a cat converter.
Mine had the dyno max cat back and a 40 series flow.... at 65-70 cruise it drove me up a wall. It resonates on a 3.1 at about 2400 Rpms. Add a 24" glass pack in the I tube to remedy it.

But yeah, at Idle through 3K it was bad ***.