Well, I am looking at switching exhaust again. I have a 2004 Sierra 5.3 1500 crew cab. I went from stock to a MagnaFlow single in/Dual out 18" long muffler with dumps at the muffler. I really liked the performance that I gained from this setup but wanted it to be louder. So then I switched that out and went to a (don't kill me) 40 series Blowmaster. I know I had read all the posts about how they flow weak compared to the Magnaflows, but I didn't think it would be that noticable in the low end. However, I do absolutely love the sound I get from the 40 series.

My question is this, I want a muffler that sounds like the flow, but gives the performance of the Magna. I am looking at maybe either a smaller magnaflow the 14" long or even a 4" round ( I hear these are loud), and I am looking at the Bassani Street Competition 4x8x14. Problem is, some, actually most of these the magnaflows and the bassani's only come in single in/single out. I have been running single in/dual out and don't know if a single in/out would make a difference in sound and power froom the single in/dual out.

Or would it be better for me to go even with 2 single in/single outs in true dual fashion? I really just need to purchase the mufflers, I work in a custom welding/fabrication shop so the piping is not a problem.

Anyone have any other suggestions for the muffler that I might need to look at?

 

well if you still have your cats and want something to flow better then a 2 chamber flow but want the sound then get a 1 chamber flowmaster. the sound is very close proabbly more aggressive then the 2 chamber and it flows alot better. Or you could step down to a magnflow small casing liek you described. if you dumping it their is no reason to run one in and two out it doesn't make any difference. IMO

 

This is my opinion and I understand that others feel differently, but it sounds to me like you're more interested in sound than performance. Again, in my opinion, I think the reason some of the systems have only a single exit is that it will provide better performance with your mods. True duals would work better with more extensive modifications, but you will probably get the best balance of sound and power with a shorter single-in/single out Magnaflow with a 3.5" to 4" tip. Good luck!

 

No make no mistake about it TarheelZ. Performance is just as important as sound is in this matter, which is why I am not satisfied with the Flowmaster. The Magnaflow that I originally had was a 5x8x18" body with 3"inlet/dual 2" out. The performance from this muffler was great, no doubt about it. But at idle in particular, it was silent. I am looking for the same type of performance from a new muffler that has good sound at idle and takeoff. At cruise it can be quiet for all I care.

I have considered going with a true dual setup also, but have never had true duals on any of my trucks and am not real sure about what all I need to do so and if the gains are really worth the extra cost.

I have my current mods listed below in my sig and I am in the process of adding FAL 292 E-fans, ASP 25% reduction crank pulley, Hughes Performance 2500 RPM Stall Torque Converter, Transgo Shift Kit, and Covette Servo. Also may add headers down the road. This will be about all the mods that I am planning on doing. Maybe a cam eventually, but that will be a long way down the road.

 

What kind of performance difference have you noticed going from the magnaflow to the flowmaster? I've been thinking about ditching my magnaflow for a flowmaster or hooker muffler to get a little low end torque improvement and a little more sound.


GregM

 

Well, like I said, I had an oval body magnaflow that I got from a local muffler shop and it was a larger one (5x8x18" long single in dual out) dumped after the muffler. The performance felt lower when I first installed this unit but when I paired it up with an air intake system it was great. When I replaced it with the 40 series flow, cause I wanted more sound, the low end power(torque) dropped. I mean, its all a seat of the pants thing, but I know for sure that I have lost a little.

I have never really been able to spin the tires much from a standstill (redlight/stop sign/ etc.) But from a slow roll--5mph, 10mph or such with the magnaflow, I could stand on it and break the tires loose quite a bit. Once I installed the flowmaster, that all stopped. Granted I can still do this if I put the truck all the way down into first gear, but before with the magnaflow I was doing this in OD. It just feels like I have lost a considerable amount of takeoff power.

 

seriously try a 1 chamber single 3 inch in and out dumped. it flows really well and is used alot on race vehicle but it also sounds really good as long as you have the cats on. If you go true duals you will loose some lowend unless you keep your cats. I personally wouldn't waste the money again on it. or as you stated go back to magnaflow and get the smallest case you can.

 

I think I am going to just go with a MagnaFlow. Just trying to research and find the right one now.

Got a question though. Since I am definitely keeping the cats. I live in TX, pretty much have to or they'll have my hide when I try to have it inspected.

But magnaflow has a muffler that has a 4"x9"x11" body with 2.5" dual inlets and 2.5" dual outlets. The pipes inside the body of the muffler "X" with 2.5" diameter pipe. Would this be a good alternative to a true dual system. Seems like a muffler of this nature would eliminate the need of an x or h pipe since the muffler has an x inside the body.

Don't know, I sent the techs at magnaflow an email basically telling them what I am looking for and what I am thinking, so hopefully I can get an answer back from them. I've already got a guy here at work that I am pawning the flowmaster off on as soon as I get my new one in.

 

Yeah good 'ol Texas-I got my Z28 inspected last year with no cats(off-road Y)and it passed and all. Just got to know people I guess.

 

yes that is the perfect muffler for a true dual setup. they call it a built in x pipe intot he muffler 02denalie has that muffler on his truck with no cats I believe.