Flowmaster 40 Series...
 

Got a question. My FM is very deep and decently tight at 1200-2000 rpms. It resonates alot. then from 2100ish-3100 rpms, it does not resonate much at all and is gargly. I barely hear it inside. From 3100 on, it resonates a decent amount and is very tight but nothing like 1200-2000. Is this normal? 3.4L V6.

yep thats what you get with a 14'' muffler

okay, thanks. I didnt know if something was wrong or what, because i the sound level was changing so much.

yeah. mine has a drone around 1500-2000 rpms.

and after 2500 rpms it gets quieter.

So drone is just resonance?

try putting a high flow cat on it

yeah thats it.

Being that the stock pipe is 2.25, what is the ideal size pipe for maximum performance with a single rear exhaust? What would a larger size do? Better sound? More power?....

stay with the stock size

Trust me... stay with the 2.25 and you'll be better off.

Alright. Quixk ?, I have a puttering type noise fromt he engine. Is it the belts? Someone told me it might be, but i wanted to hear it from the pros :bigok: . Like i said, its a puttering type squeak sound.

they say stay with the stock size becausee overall if you upgrade to say 2.5" you'll won't have enough backpressure in the flow of the system and then you'll lose more than you want on the low end power.

the noise is coming from the engine bay itself? is it only when it starts? cold weather? how many miles do you have on the car? etc.

i hope you're not talking about the gurgling sound when you're decelerating b/c i love that sound. idk why either!?!?

I love that sound too. Like, when I start it below 50 degrees, and it squeaks non stop. Sometime when its warmer its not as bad, but its not a steady "hum" when the engine is on. 121000 miles. I really think it is the belts. Havent been changed in who knows how long. Timing belt was changed at 75K.

ahh yes i love the popping/gurgling sound that mine makes when you let off really makes it sound a little v8ish

my truck sounds the same with my 40 series.
my belts do the same thing also, the damn alternator belt.
try tightening them a quarter to half a turn on the tensioners.

i have the 2.5" exhaust from TRD and it does have a lot of backpressure. i did also lose low end power but when you hit the RPMs, it really goes :hillbill: