Hi all,

I'm just lost for words here. I had catback + catdelete pipe. Then got a 3" front pipe installed today and the exhaust seems quieter??? Does this make sense??? Doesn't less noise = more restriction???

Thanks in advance

 

If you installed a 3" DP without a cat and you already deleted your second cat then what restriction could you have? Seems to me the exhaust note would be deeper, not necessarily quieter.

 

I used to have a stock 2.5" dp then got 3" dp. Well that exactly what i mean. The deep rumble i used to have with the stock 2.5" dp has quietened down with 3" dp.

 

Hm, I was thinking, if the pipe wasn't installed correctly (maybe slightly misaligned), would this happen?

 

Good Lord-- maybe the new pipe is made of a better gauge steel, is coated, have you wraped it? Lots of things can lead to noise being reduced..that doesnt equate to more restriction all the time.

 

Poor fitment would make it louder not quieter - especially in-cabin since thats around where the exhaust would be leaking out.

 

True this.

 

You could have had an exhaust leak, or as someone mentioned maybe the new DP is built better than the last one.

 

You went from a stock downpipe to a 3" and its quieter? That doesn't make sense. Any cats ?

 

This is true, NVH is a crazy thing.... for example, have you ever seen a mass damper? Its just a chunk of steel, or rubber coated steel that is attached/hanging to the exhaust pipe to reduce NVH. Its a way basically to change the natural frequency of the part.
NVH is controlled mostly through 3 things I believe.
1. Absorbtion
2. Direction
3. Restriction

So it is certaily possible to have no flow degregation and make it quiter