Hey everyone. I just got the SS 5x8x18" Magnaflow installed (97 V6) I like everything about it except for a slight drone at around 1850rpm under load. I'm not sure what could be causing this resonance because other people here with the same muffler seem to have no drone problems. I even replaced the U-type clamps with SS T-bolt band clamps and it helped a bit with the noise.

I'm thinking of getting either the 5x8x24" or the 5x11x22" SS Magnaflows, but I am concered about those because they have a 2.5" inlet/outlet and I know that my pipes are 2.25". Would using these mufflers affect much? Thanks in advance!

 

Seems to me that you might be more susceptible to being annoyed by the droning than others might be. Certainly sounds like you've done what you can to help... when I first got mine installed I found that if I listened carefully enough with my radio off that I would be annoyed by the tire noise and the exhaust drone. Now I just love hearing it

 

its an aftermarket performance muffler... i liked the drone i had with mine... but im wierd like that.... i also love the hum of my tires....

a 2.5" will be fine, any place installing it will have adapters....

 

i welded a 5x8x18 and pretty much cleaned up my exhaust, replaced bolts, etc. and mine was making a weird noise too, come to find i had a small exhaust leak around the flange, but the magnaflows tend to resonate without the baffles in them

 

this may be a dumb question but i have heard that the magnaflow muffler sounds better than a flowmaster 40 series and has a deeper tone, therefor i want to put one on my taco with a 2.7l in it, exactly which magnaflow muffler do i need

 

i just sold the one that used to be on my truck.. it was the size listed above... not sure if it was stainless steel, but it did have a very shiny case.... i currently have a flowmaster 40, and the magnaflow did sound better.....

 

magnaflow recommends 2 1/2" dia 5x8x14, i put in a downey header with a 2 1/4" 5x8x18 muffler just to retain some back pressure, so far im pretty satisfied with it and im not even geared, but im thinking bout switching to a dynomax or something thats not freeflow

 

Maganaflow help here
http://pnw4runners.com/exhaust/exhaust.htm

 

I'm the one that bought it and I do have a little bit of resonance, It sounds awesome if your outside the truck but the resonance is a little annoying.

Considering how bad my muffler was to begin with it is a huge improvement.

 

Thanks for the replies everyone! I tried that link a while ago already, but the 24 inch magnaflow sound clip doesn't play on my comp (I'm not sure why either). My main concern is if the 2.5 inch inlet/outlets on the longer mufflers will hinder performance. I read that when the diameter of the pipe increases, the gas will expand and cool causing it to slow down. If it cools where the muffler is then it is forced back to 2.25 inch piping wouldn't that be a big deal?

 

I dont mean to hijack the thread, but if you go onto magnaflow's website and listen to their sound clips. They've got a sound clip of the Tundra Reving in place. Oooooooh man... that sound made me drool all over when i heard that. That sounds d@mn goooooood.

 

Quick question though... i've read on this forum somewhere that the 3.4 V6 4runner engine does need SOME back pressure. Is this correct? Since these mufflers are relatively freeflow. Is that not enough backpressure? Or if i stick with the stock 2.25 pipe should i be ok? I'm a mix of highway/city driving. So... i sort of need low and high end power. I dont want to loose either.

 

i tried to listen to the sound clips to decide between the magnaflow or the 40 series but it really does me no good because we have no sound clips of 4 cyl. vehicles specifically the 2.7

 

Aline- all engines require some backpressure. no back pressure usually can cause valves to burn out prematurely. so can an exhaust leak over time. I have heard of people running the larger 24" without much complaint. Have also seen some street cars with high cubes run 2 mufflers on each leg to quieten it down a bit.

 

Ok... so the answer to my question is...

 

Maybe this will help...
I upgraded from 265/70/16 to 265/75/16 and put in a 3" suspension lift. I was really starting to notice the lag in acceleration but after putting in the Magnaflow 18" I did notice some pep back in the gas. Now I can't tell you that it worked scientifically with any fancy shmancy graphs but I can tell you that if this set up was supposed to *hurt* performance than I definitely would have noticed.

 

I like the drone also. I see it as a perk for having a high performance mufler.

 

Aline- you asked if the 3.4 needed some back pressure. I was only adding that all engines require backpressure. thats all

 

Oh ok, i thought you were saying that since the magnaflow is a straight flow, that it wasn't enough back pressure. But i think since many people are running the magnaflows here, that the back pressure is adequate.
With that said, the factory 2.25 tubing should be optimum correct?

thanks

 

That's where you get into trouble with back presure, running too big of a pipe. There are charts whith pipe size Vs. engine size at mufler shops. Don't go way to big your you will get screwed.