Hey im trying to decide on an exhaust system. I want a good sound but i want to gain performance, or at least not lose any, so i figured id go with magnaflow instead of flowmaster but now i called over to muffler king yesterday and the guy tells me im better off to go SI/SO with a split pipe to two tips. I always heard that everyone was going with the SI/DO so now im lost. which should i go with? also, whats the best size pipe before converter and after to not lose backpressure and torque but to get the best flow?

 

i think Zach should post on this one... hold on let me get him out of retirement for a min.

 

ive had both magnaflow and flowmaster in a SI/DO setup, personally i like the flowmaster much better, sound, performance is ok, but you dont get much from an exhaust anyway. i think a magnaflow would work much better on our trucks with SI/SO 2.5 all the way back.

my current pipe size with the flowmaster is 2.5 in and 2.25 dual out. and it was the same with the magnaflow. i lost back pressure with the magnaflow but its not as noticable with the flowmaster. if you want duals do the flowmaster if you want SI/SO do the magnaflow. magnaflow makes a nice Stainless Steel kit that is like 379.99 SI/SO.

but hey its really up to you and what you want, but personally i will never go back to a SI/DO magnaflow setup agian.

 

BTW the flowmaster sounds a heck of alot better then his magnaflow his mag sound almost stock...

 

no worse than stock

 

here are some vids of my truck, maybe this will help

stock 04
http://www.zabeard.com/zabeard/vids/stock04.mov
dual magnaflow setup
http://www.zabeard.com/zabeard/vids/mineold.mov
dual flowmaster setup
http://www.zabeard.com/zabeard/vids/minenew.mov

 

I love my SI/DO. I noticed a bit more low end power. I love the soft rumble. You can tell it's there but it's not in-your-face loud. I went with 2.25 I think. Just dumped in the rear, no tips. They'll just get damaged offroad anyway...

 

ya, its hard because since it is expensive, i want the best performance and sound. did u lose any torque with your flowmaster?

 

If you're patient you'll get an amazing deal. I bought a used (1yr) Magnaflow on eBay for $17. Plus shipping was like $36. Don't buy a full catback system. Buy the muffler and get a muffler shop to install it and bend the pipes for you.

 

i guess now that i notcie it you guys(bryan and Matt) have the older 4.0 and maybe the magnaflow is better for those

and there was no loss in torque with the flowmaster if any it was better than the magnaflow. on the SOHC the magnaflow makes most of its power in the high rpm range and that is where the magnaflow shinned with my flowmaster i think it helped the motor in the low rpm range which is what i wanted.

 

why do you guys insist back pressure is needed? i dont care what engine u have, back pressure is not a good thing.

what dictates performance is pipe size which effects exhaust velocity and scavangability.

Ask D., he ran a flowmaster and lost torque. installed a magnaflow and gained a good amount of torque...plus his set up sounds REALLY good.

performance peddler has good prices on magaflow mufflers...

 

I've read a lot of places referring to Flowmaster as Flowdisaster. That the baffles are for sound and not flow. I neither know, nor care. I just think they are too loud so I don't like them. Magnaflow is a wonderful low rumble. And I definately noticed an increase in performance so I will recommend them for many years.

 

Does anybody know why the Magnaflow bolt on kits don't fit edge models???

Thx

 

100 % correct. the claims they give are almost always got bent 8s and they fudge the claims. anyone can squeak a few hp on a dyno and make a mod look like it adds power.

 

Ya the 4.0 has a ton of low end pull, but i wish i could get that same pull after 3500rpm. ya, i am planning on getting the muffler and gettin a shop to install it. each place i call is telling me that it will be about 350 bucks..is that reasonable?

 

Which 4.0?

 

the ohv has low end power
the sohc is alright but my ohv rocks...

 

alright then what did i do wrong? my magnaflow sucked 2.5 single in and 2.25 dual out. and when i mean sucked, no better than stock.