hey,

have a 98 5.9

do the flowmaster exhaust systems really give enough hp and or torque gain to warrant the outlay of cash? I am not all into the rumble sound, too busy listening to rock music and playing air guitar. I have been contemplating a cat back system w/a 60 or 70 series muffler. Also, do the 2 pipes out help? They make a singel exhaust and was wondering if that is just as good as the duals. I am leaning towards the dual pipes but was wondering if they really made a difference or not. Again, I am going for performance not a noisy truck.

thanks to anyone who can help clue me in

 

if your going for more for performance then sound or looks, then i would go with a 3" single exhuast with a flomaster 40 series delta flow. A 3" will flow the same or more then a 2 1/4 or a 2.5" dual exhuast and will cost less because your only running one pipe

 

70 series will be like running stock (sound) the duals are more for looks ..i ran duals , single 3" and now ,stock.. i seen very little difference in hp /TQ . if you just want a slight rumble just cut your old muffler off and put in your flowmaster . 40 series you get some noise in cab but loud outside , 50 series hardly any sound in the cab and a very little rumble outside.. take a look at the 50 series , last thing you want is spend the money on a stock sound ?? .

 

I'm going single too, but the 40 deltaseems to chart a little loud

 

Question...what diameter is the piping stock for the 5.9L? I've considered doing this a few times since EVERYTHING is overpriced here in alaska and all the shops are quoting me $500 for a set-up...

 

I went with the Magnaflow on mine. Not as much of a rumble as a Flowmaster, but enough to get peoples' attention and save my wallet.

 

what about a cherry bomb glass pack muffler. would that sound good on the stock exhaust or just annoying?

 

I went with the Delta Flow 50 and it is: #1 much louder than I thought, it makes a really good rumble outside but just a nice tone inside, not louder than the radio, you just notice it. When I thought I was getting bored with it, I had the mechanic checking out the steering and he took it down the road and it sounded like a muscle car, I was soooooo in love again! #2, immediately after it was installed, with dual 2.5" pipes and 4" SS tips, I noticed much more power right through the 2k rpm area. The stocker seemed to get "stuck" in that rpm and now it just sails right up to 3k rpm. Also mpg went up 1 in the city. Mine was installed in a local shop and cost about $400. But you can order just the muffler for $80 online and cut the old one off and clamp the new one in with a turn-down for probably ~100-150 bucks I would think. Best mod I've done. According to that chart ^ ^ ^ the Delta 50 seems in the quiet range, thus I can't imagine what a 40 would sound like!

 

Guys, thought i'd throw this out there to you.

I was a GM technician for 5 yrs, been working on cars for 10+. Flowmaster is by far the worst flowing mufflers i've ever installed. They have a few that are decent, but for HP/dollar they are the worst.

Dynamax and Magnaflow both flow TONS better cfm, and make more power on the dyno (seen it personally). They also sound different, and better in my opinion.

FWIW...

 

Dynomax or Dynamax?