I want to convert over to a 2.5" true twin exhaust setup, using the Magnaflow 2.5" X-pipe and 2 of their mufflers. My problem is that most of the mufflers I am seeing, especially the ones everyone else here is using like the 14829, have a 2.25" inlet....

#14829
2.25" Inlet 4" Diam. Tip
Double Wall, Angle Cut
7" Length
14" Muffler Body Length

Should I run 2.5" pipes into the 2.25" inlet? Seems like I will be loosing performance. Or I could go with:

#14835
3" Inlet, 4" Diam. Tip
3" Internal Race Core
Double Wall, Angle Cut
7" Tip Length
14" Muffler Body Length

And run the 2.5" pipe and then expand to the 3" inlet. The mufflers are very similar in size and shape, so it will still look as good as the 14829s, but just give me that extra little bit of high end power. Opinions? Thanks!!!

 

if you have turbo in your sights down the line, i would go with 3" all the way thru.

 

i ran into the same problem and just ended up flaring the muffler inlet. Dual 2.5 is very large and still plenty for FI setups. Must supras run single 3-4" pipes and twin 2.5 is larger in area.

 

Yeah, I know 2.5" is plenty large enough, I just dont like the idea of running it to smaller mufflers.

 

Then get mufflers with 2.5" all the way through. That's what I did.

In Australia, Lukey/Walker. In the USA I think they are DynoMax or something. UltraFlo.

 

How loud are the DynoMax's? The reason I want to go with Magnaflows is because of their sound. I've heard them a lot and like that they arent too loud, and they look good on the SC.

 

Well I have the V8. I have 1 cat, 1 pipe and 1 muffler for each bank. The mufflers are the UltraFlo straight throughs. My car is LOUD. Other V8 owners tell me an X pipe would help considerably. I will add one when I switch to headers. If I want to get it quieter still, I would add another pair of mufflers in the middle - probably the cannon style resonator ones. My mufflers are also 2 inches shorter than stock as the store was out of the 16". This might make a few % difference too.

In my experience, all of the straight throughs for the same diameter and chamber size, are about the same volume. Some have slightly different notes. When all you have is a chamber with a perforated pipe going through it, there is only so much you can do to quieten it down. One brand to the next can not be that much quieter if they truely are the same design. The smaller chamber (the fart can cannon style) seem to be noisier than the double offset style I have. I guess that would be proportional to the amount of packing I have to eat noise.