Do you know the part number for the Magnaflow muffler you installed on your 2007 LTZ???

 

My invoice did not list the Magna Flow part number. I will check with the shop.

 

Just installed the Magnaflow 12589 on my 07 LTZ and left the resonator on.... Needed a few inches added to make it fit... Not much difference, at all, in sound... Probably gong to take off the resonator and add a tip tomorrow... Anyone know how much sound this will add???




2007 Tahoe LTZ

 

champagne
installed the same muffler you bought... had it on with resonator for about 3 days, went back and had the resonator cut off and a magnaflow oval tip installed. No regrets very happy with the sound. Just the right kind of loudness to let you know you have a V-8 with 300+ horses. sound is nice and mellow at idle, but when you add the gas the sound lets you know its all V-8.
Big D

 

Cat Back vs. Muffler Alone
lets look at it like this:
pipes main job is tolead the air amongst other things out of the engine.
muffler's main job is to absorb noise thus the name MUFFler.

Now before I get hammered for saying that, there are other functions these parts provide but in a nut shell this is what they do.

In a performance muffler, the main job is to free up slowedflow, and create sound. Naturally going to a less restrictive muffler will free up some ponies by allowing the air exchanger (engine) to flow more air.

BUT the piping is whats used to get the air out. If the piping is restrictedwith things suchas bends ordiameter changes,this can slow down the process more than the muffler.By using mandrel bent pipes the air can move at a smoother pace with lessdistortion thus expelling the air faster freeing up the engine.

Most mufflers are quite universal even vehicle specific in relationsto thesize, shape,inlet and exit locations, so they canuse the same muffler exteriorsizes in differentapplications. What makes the mufflers different from vehicle to vehicleis the inside. This is what changes the part numbers. In some vehicles themufflers sizeare so unique they fit that applications only.In the Flowmaster its the interior pattern of the plateswhich changes the tone of the exhaust.In Magnaflow's its the packingand perforations thatchange the sounds.

When most compaines dyno tune the catback system to a specific vehicle they make changes to the location and bends of the pipe to get the power gains not the muffler. Once a muffler is flowing freely the only thing they can change in the muffleris the sound orflow.

So in a not so short of way, A catback exhaust system is designed to yield better performance gains than a muffler only application.

 

Thanks for the info Big D.... Have you noticed any change in performance? I hate to say it, but it feels slightly sluggish and is requiring a lower set speed to stay in V4 mode, it used to maintain at 38mph but now I have to drop the cruise to 34 to stay in V4 mode....??? Am I imagining things??? Which tip did you put on? I want to "dress it up" and make it more refined looking... I have been looking at the oval tips but can't decide on the length and if I should go straight or angle it out the side... any pics of yours? Thanks again -p

 

champagne
I am not an engineer, so my opinions are justmy personal observations with that being saidI have noticed no performanceor mileageimprovements at all. The difference in sound is sufficient reason to investin the exhaust system. Magnaflow is stainless steel and seems to have positive reviews on this forum. Removing the resonator may have or may not have made much difference, however,the exhaust tip could not have been installed with the resonator in place.I have a magnaflow oval tip (side exit). Altogether I spent about $200 (includes TTL). I am sure I paid too much since it seems like I am not good at getting things at the lowest price that other peoplepay (or claim to have paid)

 

I read on another post that it takes about 30 minutes of driving for the computer to adjust to the new back pressure.

 

73shark, I think you're right about the break in period... at first it was sluggish and sticking in V8 mode, the mpg was reading 85 on a down slope but it was still showing V8 and doing other funny stuff... Seems to be working great now.


BigD would you happen to know the model number of the tip, was it the 35171? Can you post a picture? I want to do the oval tip, but I can't decide if I want to run it out the side or the back.... Not sure how you got away with $200... I got the muffler for $89 and the tip for $68 at performancepeddler.com, but it was$65 to put the muffler on and it's gonna be another $35to cut the resonator off and extend the tip.... total cost.... $257.... guess I got hosed on the installation... should have done it all at once...

 

Pretty good, $200 for parts and labor. I paid $155 for parts and labor (only replacing the OEM muffler) and it will probably cost ~40 labor plus parts to remove the resonator and add a tip. I am also wondering how it sounds without the resonator and the look of the side exit tip.

Do you have any rasp (kind ofsounds like something is flapping and interfering with exhaust flowor as my wifeputs it, farting sound [:'(])without the resonator? I did the same thing with my Infiniti QX4 and there was a lot of rasp [].