ok currently i am running a true duel set up with no cats and just two mufflers on the end(monza. yeah i know they suck) with an rb header. question is i want it to be a little quieter and was wondering if i got the rb duel pre scilencer and after that collected the exhaust to a single and put a dolphin tail(turn down) muffler on the end 1 would it be quieter, and 2 would i loose power from going duel to a single at the end.

 

Any time you collect the pipes, tuning the exhaust gets trickier.
I ran dual sliencers on a full dual setup. Easy tune, good power, nice tone, not loud.

 

yeah, i want to go single so i can use the turn down style mufflers be cause all of them are 3 in inlets and theirs now way i would run 3 in duels, i mean if it dosent hurt i would go right up to the mufflers and make the pipe expand but i think it wouldnt be any good, but i might be wrong.

 

Hear's the setup.



Here is a short video taken while pulling out into traffic on a short on ramp:
Link to video

 

I'm running RB dual header>a pair of john deere tractor mufflers>glass packs. Setup sounds redneck, but actually turned out very nice. The tractor mufflers create a nice tone without offering much resistance, and the glass packs enhance it, the tone is deep and throaty. I've even gotten compliments at red lights from v8 guys (they ask if I've got a v6).

 

The exhaust set-up on my REPU are with two magnaflow mufflers. I've got the RB road-racing header that has the dual outlet into a y-pipe/collector into a single 2.5" pipe inline with a magnaflow muffler (in place of a glass-pack) that shoots into another magnaflow muffler that exits just behind the right rear wheel. The end result is a nice deep mild tone.

 

I'd say go for it. Having the collection that far back will give a noticeable amount of +torque, which will be awesome. Consider them a SUPER long-tube header.