exhaust

[jdlvulcan]

I am looking for help and opinions on installing a dual cat back system on my 03 x-cab 5.3L. I would like to find a system thats not overbearing in the cab so you can still hear yourself think but am interested in was the pick in the low end high end or both and was there any increase or decrease in your mileage as I currently average 14.5 around town and 20 highway doing @ 65 mph. Thanks for your help

JdlVulcan

[snoman]

As general rule of thumb, with true duals you will lose low end part throttle responce most of the time and sometimes city MPG with it. I nice big single with a good flowing muffler is a good compromise.

[silversport]

...also on some, the fewer bends, the less loss of power...my Corsa has absolutly NO resonnance and it is the one into 2 pipes out one side...I liked the thought of the 2 pipes out the back but was told that the bends needed to take 2 pipes around the spare and all robbed power...just a thought.

Bill

[TarheelZ]

As general rule of thumb, with true duals you will lose low end part throttle responce most of the time and sometimes city MPG with it. I nice big single with a good flowing muffler is a good compromise.

I agree with Snoman on this. When I bought my truck, the previous owner had installed an IMCO muffler with dual pipes and 4" tips. The truck sounded pretty good but I didn't particularly like the large pipes so I had a local shop replace the duals with a single 3" mandrel-bent pipe exiting in the stock location with a nice 3.5" tip. Looks great, sounds great, runs great!

[fastdrvr23]

I am looking for help and opinions on installing a dual cat back system on my 03 x-cab 5.3L.  I would like to find a system thats not overbearing in the cab so you can still hear yourself think but am interested in was the pick in the low end high end or both and was there any increase or decrease in your mileage as I currently average 14.5 around town and 20 highway doing @ 65 mph.  Thanks for your help

JdlVulcan

I've been really pleased with a custom setup I had made with a Magnaflow muffler... Single 3" in, Dual 2.5" with 3" stainless tips. (The part #'s are in my sig, along with some videos of what it sounds like)

 

Very little to no resonance on the highway, mileage improvement (both city and highway), midrange and top end performance increase mainly (No noticeable loss in low end at all) and a great sound when I am into the throttle heavy. Everyone that's ridden in the truck has liked the sound, and they've also said they couldn't believe it was so quiet on the highway.... Good stuff!

 

Here's the post with the clips: http://www.gm-trucks.com/forums/index.php?...17&hl=magnaflow

[LikeaRock14]

I've always liked the sound of Fast's truck, had to go listen again

Well, w/ the right true dual setup you can find an increase in performance all through the rpm ranges, but a lot of times this can only be achieved w/ a set of long tube headers to go with this. a split dual, or even like Snoman said, a 3" single side swept will still give you great performance and mileage increases. I actually gained 3 mpg on my 454, which is hard to do. Of course that was after the intake went on too. Interstate driving I can easily get 15-15.5, which is d**n good for a 454 w/ 4:10's.

 

The easiest and most cost effective way to gain mileage and performance is to run a split dual, like I said above, or even the single. A 50 series Flowmaster, Spin Tech Sportsman Street XL, Magnaflow 18" or 24", Borla Pro XS, Super 40, etc, should all be great for your application.

I'd elaborate more but I need coffee, lol

[dr9672723]

15 mpg with a 454 and a 4.10 axle? That's terrific.

[LikeaRock14]

15 mpg with a 454 and a 4.10 axle? That's terrific.

F-ing A it is! but like I saidm that's interstate. Around town, and short trips, eh I'm looking around 11-13, but that's still pretty dayum good!

[dpb119]

I have an 03 5.3L 4x4 EXt cab w/ 3.73 rear lock. I'm also considering an exhaust, but was worried about mileage and power loss. Live in PA and need low end for mountains. Some towing, but nothing real heavy.

 

I like the sound of that 4.8L w/ the magnaflow and I didn't seem too overwheming in the cab at cruise. Think that would work for my 5.3?

 

I could also use some recommendations for low cost mods for my silverado. I'm a noob at the new vehicles. I'm from the old school- build the motor and run CAM 2 fuel. I suppose the bug never goes away, it just hibernates for a while.

[LikeaRock14]

I suppose the bug never goes away, it just hibernates for a while.

I hear ya! I'm always tampering w/ all our vehicles, seeing what I can/can't do.

 

Living in PA, I guess you

re where there's snow, so the stainless Magnaflow system would be a great way to go. Magnaflow's mufflers all seem to have low interior sound levels at cruising speeds, and have pretty noticeable increases at the top of the rpm ranges. As for losing low end torque or gaining any, it depends on existing mods, gear ratios, and the engine itself. Some might have come off the assembly line w/ slightly different tolerances, so the power curve may/may not be altered too much.

To gain low end torque that's lost, or gain any at all, an air intake paired w/ some sort of ecu upgrade, preferrably Westers.

Overall, you can't go wrong with Magnaflow. Great produc, quality, and a hell of a price for what you get