I have an Espelier dp, invidia tp and a blitz nur-spec cat back. I've gotten pulled over a couple times for noise and started putting the silencer in. It's nice and quiet now but I might as well just put a cork in the tip. The power loss is more than I would like.
I installed a HFC and took out the silencer hoping for a happy medium but the noise level is the same as having the tp.

Really, I want to know which would be the least restrictive combo:
a). 3" dp --> TP --> stock cat-back
b). 3" dp --> stock cat --> Blitz cat-back
c). 3" dp --> TP --> blitz cat-back --> silencer

Other opinions are welcomed...

 

get a resonated test pipe....

 

A and B are going to be similar at modest power levels. C is definitely much worse.

My recommendation is to sell the blitz piece and pick up a quieter cat back exhaust. There are several of them out there that are not a heck of a lot louder than stock, but will only sacrifice a few hp with modest mods. Just search for quiet exhaust or something like that, thre are a number of threads on the subject.

 

Thanks.
I'm due for an inspection in Feb., so I think I'll put back the stock cat for now and then start researching again before spring when it warms up a bit. I don't really like to wrench in the cold.
Hopefully the cat will quiet it down enough. I'm pretty sure that cat-back was pretty loud even with the stock dp and cat when I first got it.

 

I have a dp, hfc and an espilir catback and the noise was too much as well. Had the same issue with the silencer robbing power so for a quick fix, I actually drilled holes in the end plate of the silencer until the noise level was acceptable. Still lose a bit of power but figure the balance is fine for the street until I find a new catback.

 

An exhaust with resonators inline would help. Maybe pick some up and have them welded in place.

 

I have an Espelier dp, and an Invidia N1 3" exhaust with the inline resonator (in the B pipe). I also have a resonated megan test pipe. The combination is relatively quiet.

 

I'm in the process of buying a resonated TP from another member. Hopefully, that combined with a different cat-back will get where I need to be as far as noise and still be making decent power.
I'll still be reinstalling the cat for a few months till I get inspected since I believe I'll have to do emissions testing this year. Judging by the amount of soot things thing spits, I doubt I'd pass.

 

My advise is to go custom. Get a 3" cat-back with two big 3" resonators and a big Magnaflow muffler. Sell your cat-back and use the money to pay for it.