Hey guys, i'm looking into adding a performance exhaust system to my Silverado 5.3L and i'm wondering what opinions you have as far as going with the dual exit vs. the single side. Do you get much more HP and MPG with the dual? I will be going with Magnaflow and the two systems i'm looking at are a dual 2.5" pipe with 3.5 tips, vs a single 3" pipe with a 4" tip. Let me know what you think, thanks!
04' Silverado LT 5.3L w/ S & B intake, Banks Monster Exhaust Cat-back 3" to 5" Tip
I installed the Magnaflow 3" kit with the 4" tip on my truck about a month ago. I love the sound, it's nice and mellow at idle and rumbles pretty good til about 4k, but after that, it sounds like a damned pro stock car (not quite). I got the single over the dual kit for 2 reasons. 1st, I've had dual exhaust kits where the tips aren't positioned perfectly or not been level, now I'm sure Magnaflow has this down pat and it's probably not an issue but I didn't want to take a chance. 2nd, I let my truck run in the garage for a few minutes in the winter, my garage is 24x24 and my truck is backed in pretty close to the back wall, I didn't want the exhaust to discolor or fade my paint on my garage wall. The kit was pretty easy to install, the only tip I'd give you if you're doing it yourself, try not to break the factory studs at the donut flange where the aftermarket kit bolts to the stock y-pipe, both of mine broke and it took me longer to fix that than to install the rest of the exhaut.
2005 Silverado 1500 LS Z71. Extended Cab Shortbed. L33 5.3, 4.10.
Coming Upgrades:
Volant CAI
Magnaflow 3" Single Cat-Back
Superchips Cortex


If you're getting a single muffler set-up, I'm pretty sure you won't see any performance difference between a single-out or dual-out system. I won't say I'm positive because I'm not a pro, but the shop that installed my exhaust (Magnaflow muffler replacement w/ tip) told me the only thing a dual exit set-up would change is the tone.
Matt
Hallsville, TX
2005 Silverado 1500 LS Crew Cab 5.3L 2WD
K&N FIPK II
Magnaflow Exhaust
Hypertech Max Energy Programmer
Suspension Leveling Kit
Putco Element Window Visors
Carriage Works Billet Grille
TruXedo TruXport Tonneau Cover
You aren't going to notice any difference. The dual tips will give you 1.39 times the volume after the muffler compared to the single outlet but those dual tips are going to be longer than the single outlet since they have to go to the back of the truck and snake around the axle/spare tire which will probably make up for the difference in volume. Also once you get back to the tail pipes, it's not going to make much of a difference since it's so far back in the system, especially if you have stock manifolds, stock cats, stock Y-pipe because there is so much more restriction there. You should make your decision based on function, price, and visual preference.
99 Silverado Z71 4.8
2" Suspension lift (Add-a-leafs and leveling keys)
Long tube headers with 3" offroad Y-Pipe
Volant Cold Air Intake with Ram Air Intake Tube
Jet Mass Air Flow Sensor
Diablosport Predator Tuner
Previous Truck:
97 Suburban K1500
3" Body lift
2" Suspension Lift (Add-a-leafs and cranked up torsion bars)
35" Yokohama M/T's
K&N Intake
Airraid Throttle Body Spacer
Hypertech Programmer
Dual Flowmasters


The last time I had exhaust installed, I went with "true" duals, from the "cats" back. I used the FLowmasters with 3.5" tips. I don't know if a single pipe would be any better or not.
2010 Z/71 Colorado C/C
Black 4X4 w/5.3L V8
===============
2007 Winnebago Adventurer
w/8.1L Chevy & Allison 6spd.
Canyon Lake, Texas
I called the local exhaust shop today just to get some estimates and he mentioned using an accelerator muffler? How generic are these mufflers and how do they sound?
04' Silverado LT 5.3L w/ S & B intake, Banks Monster Exhaust Cat-back 3" to 5" Tip


i have single 3in. magnaflow, fits perfect, sounds great and is good up to 400 horsepower. so unless you like the look of duals or have over 400hp save your money. also i've seen duals burn full size spare tires mounted under trucks when towing heavy trailers. hope this helps .
Thanks for the info...i'm thinking of going with the single, but now i'm trying to decide how big of pipe, would 4" be too big into a 5" tip...or should I stick with the 3" 4" tip combo?
04' Silverado LT 5.3L w/ S & B intake, Banks Monster Exhaust Cat-back 3" to 5" Tip
don't know if you would like the look, but i went with the Magnaflow dual tips side exit before the rear tire. Easier to install your self. It is two peices and you don't have to go over the axle. I have yet to see another truck where I live with this set up.
2008 Silverado 1500 Ext Cab 4wd LT1 Package with 20" wheel upgrade,K&N CAI, Magnaflow Catback Dual Side Exit, Tuff Country 2" Leveling Kit, Blackbear Tune, 6k HIDS Low and High Beams, 3K HID fog lights, LED tailight bar
Well I think I decided what exhaust i'm going to go with. I found a magnaflow muffler with 2.5" inch pipes and 3.5" tips and all hangers and bolts for $235 including shipping from a muffler shop on ebay. This is a great price and i've talked to the store and some of the customers and the system sounds pretty good.
04' Silverado LT 5.3L w/ S & B intake, Banks Monster Exhaust Cat-back 3" to 5" Tip
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