Exhaust Woes

DanMan_S · January 7, 2004

I'm really set on throwing a Flowmaster 50 series Dual In/ Dual Out on my 98 Sierra z71 with a vortec 350. Yet, my nearby exhaust shop will only get me an American Thunder Cat Back DOS system with a 70 BB2 series muffler.

First of all, how much quieter would that system be than the 50 series? I keep hearing that the 70 series are VERY mild but haven't heard the observations of those mufflers as part of the american thunder system. If I'm looking for a aggressive tone from my truck, will the 70 series let me down?

As well, performance wise, I've been told to make sure that the muffler is Dual 2.25 inch outlets in an attempt to maintain the torque.. Yet the american thunder kit uses dual 2.50 inch outlets....Is there anything I should be scared of when settling with this cat back system.

Does anyone have any recommendations of good exhaust shops in the calgary area where I would be able to get them to custom build me an exhaust using a 50 series muffler? And what do you guys recommend for rust protection? Calgary weather isn't metal friendly at all so I'm gonna have to protect my investment somehow.

bfrd22 · January 8, 2004

I Haven't lived in Calgary 15 years but there has to be a Custom shop.

Look for a Carline Muffler,

I know Dennis the owner of the one here in Red Deer does awsome Custom work (they will be doin the exhaust on my 51 F1 Hot Rod this summer).

Also South hill muffler (ind), Jack lives for Custom exhaust work. Sould see the stuff on his Viper and Prowler.

redchev · January 8, 2004

I have the American thunder system on my 1998 k1500. I ordered mine from summit racing and installed it myself. Very easy to install every thing lined up and the hangers use existing holes in the frame, actually I didn't even jack up the truck. Easy 1-2 hour install. The 70 series was a little bit of a let down so I installed a 40 series delta flow with the same pipe sizes so I just needed to extend the one pipe because the 70 is about 10 inches longer. I think the system was about $300, and the different muffler and pipe about another $65.

DanMan_S · January 8, 2004

How much of a difference is the 70 over stock? Say, if you're driving with the windows open and flatten the pedal to the floor boards can you actually hear the exhaust? What about with closed windows and the stereo on

This truck and my previous one (my first) have only had stock exhausts so thats all that I'm used too. I have no real comprehension of how loud the flowmasters may be, so the 70's could be enough for my untrained ears

redchev · January 8, 2004

The 70 series is louder than stock but not noticable when cruising in overdrive. It may depend on exit location as far noise though. Mine goes straight out the back. The 40 series is noticable all the time but I can still listen to the radio and have a conversation. I would start with the flowmaster kit because it is easy to make changes. I think the 40 and 70 series mufflers have the same basic width and pipe locations only the length changes. The system on my 1998 has a 2 into 1 pipe that is 3 inches and then dual 2.5 inch out the muffler. I didn't notice any gains or loss in power either.

Cool Zr2 · January 9, 2004

Get glasspacks man, Those flowmasters are over rated.

thrush 2inch in 2inch out with 2 inch tails, it creates a sweet sound behind a v-8 vortec.

MoJo · January 9, 2004

Order what you want and take it to someone else to install. Muffler alone = $50-80.

Catback, which you don't need 'cause you already have dual cats & piped to the OE muffler, = $300+.

Guess who is trying to make extra $$.

DanMan_S · January 10, 2004

Allright, scratch my original ideas. Davenport Racing in NE calgary is getting me a JBA catback for 400$ off. It's a single 3 inch exhaust....looks really nice and wow, it sounds great. The system impressed me alot more than the flowmaster kits other shops were trying to set me up with. It's going in Wednesday so I should be terrorizing the neighbourhood by the evening.

Matt A · March 8, 2008

Allright, scratch my original ideas. Davenport Racing in NE calgary is getting me a JBA catback for 400$ off. It's a single 3 inch exhaust.

sounds factory

in the 97/98 halftons it was dual 2" from the manifolds becoming single 3 after the muffler, 3/4 tons dual 2.5 from the mainfolds becoming 3 after the muffler. not shure about z71