I am about to purchase a Flowmaster 40 (most likely a Super 40) and bolt up to my exisiting pipes. I was suprised to see the pipe coming out of the back of my stock muffler (to the tail) is 3 inches OD and the pipe in (from the Cat) is 2.5. So my question is - what size muffler should I get?... a 3 inch In and Out?... or 2.5 in/out?... would it be better for back pressure reasons to get a 2.5?... is there that much differnace between 3 inch and 2.5 inch on a stock 5.2?...I want it louder, deeper but dont want to loose a lot of bottom end. Also, is there really much differance in sound from a Delta 40 and a Super 40?... any info is greatly appreciated.

~j

 

Probably if you don't want to lose any low end I would stay as close to the stock set-up as possible. I have a dual outlet cat-back 2.25 tail pipes and I didn't have a noticable loss in low end. So probably get a 2.5 inch inlet with a 3 inch outlet. I also just wanted to make sure you were aware that you will probably have to add some pipe to the system somewhere, because a flowmaster is considerably shorter than your stock muffler.

 

Yea, I see where the stock muff is 30+ inches and the Flowmaster ~19 - so a filler piece is needed. What I was shocked to see is all the Flowmasters come "in and out" the same size - so I quess I have to get a 2.5 x 3.0 reducer (autozone?...). What I wanted to know is since I have to purchase a Flowmaster with a 3.0 in and out where do I bolt up the reducer - would it be ok to bolt this reducer to the Cat and then run the 3 inch filler pipe from it to the muff? I keep seeing posts that praise 3.0 inches but I am not sure where to start the 3 inches from. Any input on the differances (sound, tone) on a single pipe Flowmaster (Super 40 vs Delta 40) is also appreciated. I can not believe there is that much diff in tone and since I do almost no highway (just around the town) I dont think I will hear drone...then again...

~j

 

I have a cheaper Vortex catback that's 3" in/out. It has a 2 1/2" to 3" placed after the cat and then it's 3" to the muffler. I haven't noticed any loss in the low range.

 

Hmm...I wonder if it is different for dual outlet mufflers, as far as what size you can get the inlets/outlets, because I was told that I had 2.25 tailpipes and thats what I asked for, I'll have to check it out tommorow. As far as the mufflers RamDammit is right, the vortex sounds the same if not better than a Flowmaster, if you can get your hands on one, the only shop that put them on in my area went out of business. As far as the drone, you will hear it but if you are like me it won't bother you I listen to my exhaust more than my radio. If you have access to a welder I would just weld the reducer to the inlet and then weld the extension to the outlet. Then bolt it in with clamps if you want, but welds will last longer and be less likely to leak IMO.

 

Vortex is a Maremont brand muffler ( same folks who make cherry bombs), any one who sells them should be ablie to hook you up. The systems are listed in the back of thier parts catalog, so any savvy parts man should be able to find them. If not, I can get them for you.

The dual outlet system has 2.5 outlets, BTW all the tubing is mandrel bent (no dimples) and cost is much less than many "famous brand" systems found on the web or in performance shops. The quality is better than the "generic" systems found on ebay.
I've had my Vortex system for about 3 years and love it. The only thing I recommend is running more than one hanger per tailpipe, especially if you drive off road a lot.