muffler v cat back

[lou1]

Yes another exhaust question well I have a 2010 s2 sv6 and I'm looking at a 2.25 cat back . Something like a xforce. My question is what's the difference if I just change the mufflers ? I know the cat back will be better flowing but will it make a noticeable difference? Also is the stock exhaust 2.25? If it is would that mean it will sound the same as a full cat back if using the same muffler?

 

[nickb1993]

If u just change the rear mufflers to straight through mufflers theres gonna be drone
I have a xforce 2.25inch mild steel catback on my ute and it is louder but still quiet at idle and no drone at cruise

 

[lou1]

What if I use just the same x force muffler

 

[Nico36]

I recently looked at exactly what your doing now, should I replace with a straight pipe, look at high flow mufflers or catback?. Just bite the bullet and go with the catback, has little drone and has a nice sound on acceleration/ changing down which is what you want.

 

[bigjim92]

Your best bet is quality rear mufflers, a quality rear muffler won't have drone, or will have very little. Xforce isn't quality either, I made the mistake of buying one of their cat backs, all the welds cracked away within 9months.
Changing the whole catback is pointless, you won't gain anything as the mufflers up front are straight through.

 

[Not_An_Abba_Fan]

The original system is small and restrictive, changing the whole system aids flow.

Changing just the rears will change the sound, but depending on what you get, may induce drone as the front resonators are matched to the rear mufflers. Changing them, changes the way the front resonators work. Even going to a quality rear muffler may still get some drone.

 

[Jarp]

The original system is small and restrictive, changing the whole system aids flow.

Changing just the rears will change the sound, but depending on what you get, may induce drone as the front resonators are matched to the rear mufflers. Changing them, changes the way the front resonators work. Even going to a quality rear muffler may still get some drone.

Is not the stock system 2.25" anyway? Where does the size increase and derestriction advantage come from with an aftermarket 2.25" other than the mid-muffler? Agreed that even quality rear cans can still induce drone though.

 

[HsvR86.2]

Mine has no rear mufflers on the stock exhaust and sounds great! Has little drone but doesn't get annoying, my mate has a 6 litre with 4 into 1 extractors with twin 2.5 and mine being 6.2 litre sounded louder than his whole system, he has 248rwkw mine is stock and my car is quicker from take off beat him by 2 car lengths, we were both shocked but I was very happy

 

[dmacey]

I would have thought that a 2.25 would be more than enough flow for a car with this level of output. Upgrading to a 2.5 or 3" seems over kill. @not a abba fan

 

[Not_An_Abba_Fan]

The mufflers have smaller diameter internals than the rest of the tubing and there is a small flattened section in front of the front mufflers.

2 1/4" can be enough with the right system. The alloytec loves to rev and having a larger system lets it rev quicker. I would never fit a twin 3" to the V6, twin 2 1/2" goes well though.

An exhaust system that is engineered correctly will always be beneficial, unfortunately, there aren't many on the market. Most systems are designed for sound only or they look good. Having a bad system on your car that looks pretty is as bad as chopping the original up and just fitting straight through pipes.