[burninrock24]

I have the factory cat back with welded-in offset flowmaster mufflers. I am trying to upgrade the sound to the likes of a Magnapack or LMII. But those are bullet style, straight through designs. How can I make this work? I will be doing the work myself.

Or would I be better off buying a new catback. I have full bolt ons including a catted X-pipe.

 

[fordman777]

Why not just buy the mufflers??

SLP Loudmouth II Mustang Mufflers (Bullet Style, Pair) at AmericanMuscle - Free Shipping!

And if you need them use these....
Pypes 2.5in Stainless Steel Replacement Flow Tube Kit (79-04 Mustang) at AmericanMuscle - Free Shipping!

I am going with LM 1's on mine with those replacement pipes so I don't have to cut up my catback I am also dumping min after mufflers before rearend so it's all up to you what you wana do or you could just buy a new catback all you man.

 

[SoCal2V]

I think you'll need a trip to a muffler shop; a couple short sections of pipe will have to be fabbed along with having the new mufflers welded in place.

Or you could go with your second option and just buy the complete catback. I'm not sure it's completely worth the $400-500 the complete systems usually go for, but being able to take them apart can come in handy.

 

[fordman777]

The SLP mufflers are designed to slide over the 2.5" pipe so going and getting stuff welded is not needed SLP designed them so that you can change out between the 3 mufflers they offer. So if he goes the route I stated then he won't need to weld anything just clamp as long as he has enough pipe that is straight on the back side to slide in the muffler....again I do not know how well there design works compared to being welded but I would take it that it holds up well never heard anyone complain about SLP cat back!

 

[burninrock24]

The SLP mufflers are designed to slide over the 2.5" pipe so going and getting stuff welded is not needed SLP designed them so that you can change out between the 3 mufflers they offer. So if he goes the route I stated then he won't need to weld anything just clamp as long as he has enough pipe that is straight on the back side to slide in the muffler....again I do not know how well there design works compared to being welded but I would take it that it holds up well never heard anyone complain about SLP cat back!

I think I understand what you are saying, but I dont think we're on the same page. My problem is that my current muffler is this:

Flowmaster 942453 - Flowmaster 50 Series Delta Flow Mufflers - Overview - SummitRacing.com

And the muffler I plan on buying is this:

MagnaFlow 10415 - MagnaFlow Performance Mufflers - Overview - SummitRacing.com

So you can see how essentially I will have to run the mufflers diagonally, which would require some fabrication. The only way I can see myself clamping on a muffler would be if I were to buy offset mufflers like the ones I have now. I have the stock cat back. Which wasn't designed for "straight piped" mufflers to be clamped in.

I think you'll need a trip to a muffler shop; a couple short sections of pipe will have to be fabbed along with having the new mufflers welded in place.

This is what I was thinking. They gave me a quote of $150. Does that seem reasonable? And just as an average, what are the power gains from an aftermarket cat back?

 

[fordman777]

Well from the way it looks to me if you get the replacement tubes then it will work if you look at the pics of both loudmouths they all look like they are taking the place of an offset muffler just my thought though but hey take it to a muffler shop if that is what you wana do.

Gains from an aftermarket catback over stock.......if you do see any it is not gonna be worth the money I would spend it some where else!

 

[FranktheTank760]

Id say just cut out the mufflers and run straight pipe with the cats still on I did that to mine and I couldnt be happier

 

[burninrock24]

Well from the way it looks to me if you get the replacement tubes then it will work if you look at the pics of both loudmouths they all look like they are taking the place of an offset muffler just my thought though but hey take it to a muffler shop if that is what you wana do.

Yeah but the loudmouths simply arent an offset muffler so I'm not seeing how that is possible without mounting the muffler diagonally, and thats the part I'm having a hard time with.

Look at the attachment. Do you see what I'm saying? Both inlet and outlet pipes are coming straight in at different locations. If I were to put a loudmouth on, then it would never line up with the outlet pipe.

Id say just cut out the mufflers and run straight pipe with the cats still on I did that to mine and I couldnt be happier

I just simply don't like the sound of it. Too much like a truck.

 

[FranktheTank760]

Not trying to be a **** or anything but have u heard it on our cars, to me it sounds just like a muffler but alot louder

 

[burninrock24]

Well duh, haha. A muffler does just that. Muffle. Straight pipes are too loud and unrefined.

 

[FranktheTank760]

To me the cats keep it refined enough but I guess its a matter of opininon

 

[fordman777]

Is that your exhaust in the picture?

 

[FranktheTank760]

No I actually dont have any pictures of my curent car ill try to post some tomorow