Looking for a little more noise & any perf. gas mileage would be an added bonus. I don't really expect it from acat back however.

Considering a Corsa touring unit. Any experiences??

Vehicle is completely stock right now.

I got an SLP PowerFlo for my Sierra. It's their quietest catback. Their Loudmouth is basically a resonator, and is LOUD. The SLP uses dampening material in the muffler (one in, two out) and is pretty quiet. Definitely throatier and louder than stock, but not at all annoying in the cab. Very quiet in the cab at highway speeds, but makes some good sounds under acceleration. Works well with my 5.3L V8, and gave me the sound I was looking for. If anything, it's a bit too quiet, but it will get louder as I put some miles on it.



All Stainless. Double-wall dual tips. It's a bolt-up kit, but I haven't seen any leaks, and have been running it for 1000 miles.



Hard to say about mileage. Seems about the same.

If the stock exhaust does not have any restrictive bends or pinches in it I would just replace the muffler.  I'm running a Spintech Sportsman XL on my Tundra and its got a nice growl to it but very little drone in the cab.  My brother runs GIbson on his Dodge Hemi and likes it so far also.  On all the Chevy's I've had in the past I've always picked up 2 mpg doing exhaust and intake.  Have not gained anything on the Yota.  Also have headers on it, but my towing power is much improved.  

Honestly if your looking for performance, do headers first, exhaust next, then intake if needed.

Bill3508

I'm no expert, but I have been doing a LOT of reading, and it seems that people say that anything but long-tube headers are a waste of money, since mfgs. are designing their exhaust manifolds with much more emphasis on pulse scavenging now.



The problem with LT headers is that you have to shitcan the OEM cats and thus get into messing with your emissions sensors. Not a big problem with an out-of-warranty engine, but a hassle if it's a new vehicle.



I wanted to get a set of Thorley Tri-Y headers, but the Thorley guy talked me out of it.

I got a 14" round-bodied Magnaflow for my 5.3L Silverado. Sounds great, no drone, and I gained about 1mpg (calculated over a few tanks of gas) overall.

Here's a soundclip of mine off my crappy cell phone form last year;

http://www.youtube.com/watch?v=ja3IoOxFNIk

Typical dyno rear wheel hp gain with headers on most V8's are 15 -25hp and 20-25ft/lbs torque.  Factory manifolds are poor on any V8 made vehicle American or Jap.  Also, you can keep cats with headers, depends on which ones you buy, and what mid pipes are offered.  Even shorties are a huge improvement over factory manifolds, which is what I'm running on the Tundra with cats, long tubes on the Goat/no cats.    Technically removing cats voids the federal emission warranty and is generally a no no law wise, but should not affect your car warranty in general besides maybe the exhaust, which most folks dump anyway.

I think you've been reading to many header manufacturer's advertisements. Did you dyno your Tundra before and after you added the shorties? Or are you just quoting what the internet told you? I'll give you 10% gains with LT headers, but not shorties. Ain't gonna happen. And I didn't mean removing the cats would void the warranty - I meant it was a hassle, since you need to mess with the ECM to disable the DTC's if you mess with the emission parts. Lots of people do that anyway, but not everyone wants to.

Unfortunately for you the stock GM exhaust on the 99+ trucks flows extremely well, minus the oil-drum of a muffler. That's the only real restriction on the stock exhaust. The rest is mandrel bent 2.75" tubing, and very free-flowing.

Frankly, you won't need LT's until you get a cam.  You'd spend upwards of $700 for VERY minimal gains––think maybe 5-8hp at the wheels.

If you want more responsive driving, the best thing you can do to a stock truck is get a tune.

I made the mistake of going with Wait4Me––it's a nice upgrade over stock, but leaves a lot to be desired; if I had to do it all over again I'd give Justin at Black Bear Performance a call and have him do a data-logging tune. There's plenty of HP to be unlocked on the 5.3/6.0 from a tune alone––upward of 25-30hp WELL DOCUMENTED gains.

http://www.blackbearperformance.com/

For more power, remove the stock cam (which is an amusingly small 190/194 110lsa, or something in that neighborhood) and throw in a 212/218 114lsa cam (Voodoo's Lunati line is great), throw in some LS6 springs and some pushrods and you're well on your way to an extra 90ftlbs tq. w/ a good tune.  Throw in a bigger stall like one out of a Trailblazer SS or Trailblazer 6cyl and get your stall up to 2600-2700rpm for more meaty torque off the line.

All this can be done for under a grand––Cam is $350 new on eBay, LS6 springs are $90 new, tune will cost in the $250 neighborhood, you can re-use your pushrods, and a stall can be had for $150 or so new or very lightly used from the Trailblazer folks over at performancetrucks.net.  

...Or you can throw money into the fart tube of an air pump and effectively waste cash.

Exhaust is gimmicky––every manufacturer claims HUGE gains.  Get what you think sounds best and run with it. Honestly you're not going to get much––if anything on the butt dyno with a muffler swap, even though the stock muffler on your Avalanche is akin to a labyrinth inside.`

Don't quite have the time now to look it up but go to GMfullsize.com or fullsizechevy.com and look up Black Bear Performance or and of Fast305s post on dyno results (I also have a few up under the same screen name).  Bolt ons are a crock unless tuning and internal mods are made....  Exhaust and CAI are the worst.  Don't be one of those guys that sound like they are going 100mph when you can't (no offense) there is a lot you can do to a LSx for very little money with and bolt ons don't cut it.

Fast305 will tell you that everything sucks except his 305 in his G20 conversion van that runs a faster quarter mile every time it's brought up...

...all with stock 3.08 gearing.

He won't let you  forget the gearing.

Fast305's got a Gen1 engine anyway, and good as they were they are they're not on the same playing field. The LSx is more responsive to minor bolt-ons than the Gen I/II were.

I'd love to do cams, springs (and roller rockers?) on my '09 5.3L engine, but that is a warranty issue, right? Motor blows up (for whatever reason) and I'm screwed, yes?



What have you heard about Westers' tunes?  I'm inclined to go with Black Bear, based on yours and others recommendation, but I've also heard good things about Westers.



I put the bolt-on exhaust bits on my truck, but only because I wanted to improve the sound. I have no illusions that doing that will give me magical power gains. Tune is next.



Also, what is your opinion on a CAI? I've heard very conflicting reports. I'm looking at an AFE Stage 2 system (when they release it.)

I don't go by anything a manufacturer states.  I have not dynoed my Tundra but others with the 04-06 Tundras have posted dyno graphs of their JBA headers and realized 15-17hp increase, and 25ft/lbs of torque with the shorties.  Have you seen a stock Tundra manifold, they are shit to say the least.  I did dyno my GTO and with long tubes realized a 20hp/25ft/lb torque increase at the rear wheels.  Plenty of user dyno graphs from good companies out there regarding headers, they are the best performance mod for the buck on any V8 vehicle.

Here we go.   All I was looking for was a little better sound w/ a quality unit.

Anyone have a corsa cat back system????


Little to no gains are made from a cat back unit & most if not all current GM products flow more than enough air w/ the factory airbox. CAI are pretty much horseshit anyway IMO on a stock vehicle.

This is a daily driver & right now, just looking for a little more rumble, nothing obnoxious.    When I want more power there will be a supercharger bolted on & be done w/ it.

Sorry man, I don't have a Corsa (and I really didn't meant to threadjack, but you know how it goes...)



Anyway, this clip is almost exactly how my 5.3L Sierra sounds with the SLP PowerFlo.  See if you like the sound.  It does have a muffler (and a muffled sound) but it's a big improvement over stock, IMHO.

Corsa is a raspy exhaust, at least on the GTO's.  They are well thought of though, look for some sound clips on LS1gto.com.  I would seriously consider just replacing the mufflers though, especially if your not interested in doing future mods.

The GMC does sound good!


Listened to some clips on the corsa & am just about dead set on thier system.   As far as mods go, about the only thing else I will be doing Is a supercarger (not sure of what make yet.)   The truck is about to be retired to justa fun/vaca vehicle in about two months.

www.chevyavalanchefanclub.com   Lots of resources there.

Ah, you're one of them folks with a "new" truck.

I'm pretty sure any internal engine work can void anything they deemed is "caused" by that modification.

Westers is another great tuner, as is Nelson Performance.  I believe Westers is the most pricey of all of them though, and does charge for re-tunes. (I could be thinking of Nelsons. It's been a while since I looked at all of them since I got my tune.)

CAI's are cool, as long as you don't get a K&N. It lets waaaay too much dirt into my intake. I have quite a bit in my post-filter dirt trap after a while. AFE is a good system, sounds good and does give some gains on the top-end. You'll probably get a bit better throttle response and maybe a boost in mileage. AFE also makes a better filter than most, so if you're going to get a CAI I'd go with AFE.

Thanks.

I have a corsa catback on an 07 silverado 6.0l, I like the way it sounds, not to raspy you do notice a bit of a drone letting out of the gas at high speed.  If your looking for better gas mileage out of it, it aint gonna happen.  Mine dropped 1mpg after the exauhst and another mile after putting on 33x12.50's, I gained them back after a tune along with added horsepower.

Just weld in a Borla or Magnaflow and keep the stock pipes along with the low end tq