2012 Roush stage 3 with headers and x pipe

[Whipple V8]

I have a 2012 roush stage 3 and have just ordered a vmp 675hp kit and stainless works 1 7/8 long tube headers and off road x pipe. I also currently have the roush axelbacks that came with the car.

my question is since im replacing all of the factory exhaust except after the x-pipe connection to the axel backs do the factory resonators restrict much or any flow? would it be benefical to remove those or get a cat back? the reason i haven't so far is i have the sqaure tip axel backs and the rear fascia to match plus i like the sound of them and roush does not make a catback as far as im aware. I dont want to choke down my headers that i spent alot on and the resonators have that dent on them so it looks restrictive from the outside.

 

[Vert]

The resonators arent that restrictive, but be warned with no cats the roush muffs are louder than a cat in clothes dries with 10lbs of rocks in the drum. I ran my car for 2 months with my roush and no cats and my opinion it sounded like a truck with glasspaks.

 

[Whipple V8]

now you got me worried, lol im not a fan of glasspaks at all i went without cats because i had a 03 whippled cobra that didn't have cats and i miss that exhaust sound even though i know it's a completely different motor and will sound different anyways. As far as the sound i guess ill find out in a couple months once the snow is melted. I'm just trying not to spend another $750-1000 bucks on a catback when im currently ok with the sound and look with the roush sqaure tip axel backs and i would have to get a new rear facsia trim to match oval pipes. but if the resonators are robbing alot of the power im trying to add with the long tubes im willing to spend the extra money.

 

[Vert]

The cats have a lot more restriction when compared to the resonators. Do you still have the roush tune and you're going to vmp? If that's the case, you won't notice the gains by removing the resonators since you'll be picking up loads of powa.

 

[TallyGT]

The resonators arent that restrictive, but be warned with no cats the roush muffs are louder than a cat in clothes dries with 10lbs of rocks in the drum. I ran my car for 2 months with my roush and no cats and my opinion it sounded like a truck with glasspaks.

+1 Off road mid pipe with Roush AB's is obnoxiously loud. I have multiple friends with this setup, it sounds good IMO. Just very raspy and loud. People have had great success with dynomax mini race bullets and that setup, take's some of the harshness/rasp out of the tone.

 

[Whipple V8]

yeah im going from stock roush pulley and tune (540hp) to vmp pulley and tune (675 hp) plus long tube headers and off road x pipe so i wont notice a loss in power. i guess to narrow the question down i was just making sure the headers and x pipe will still give me a decent gain in power while still keeping the resonators. and what would i roughly gain with a full 3 inch cat back over the stock over the axel pipes and roush axel backs. i realize proper tuning is part of it but are we talking 5whp? 10whp? or more?

 

[Vert]

I would say 10hp at the most.

 

[DaBigBone]

Catback won't get you a ton of power. Maybe 5-10 at max

 

[archerychamp3d]

I just did headers and off road x with muffler delete pipes which rele don't sound much different than roush mufflers from what I have heard on you tube. It gets loud to the point of not being a pleasant ride. the sound is nice a lot like an exotic car. But talking on the phone in car will be a chore.
I suggest going ahead and listening to some different axle backs on youtube so you can pick out a set to order.
Mines n/a and yours is force fed so it may be even louder. I read some where that all of borlas mufflers are a straight through design which might appeal to you if your worried about back pressure.

 

[Holovacko]

I also ran catless with Roush mufflers, it's very loud. Cruising speed has some drone, but reasonable. During the winter, with cold pipes, it's very loud at start up. Accelerating from traffic lights is fun though, watching the cars next to you, roll up their windows, because they can't hear radio or the phone. At the track, they actually checked if I had cutouts, it was so loud at WOT...

 

[Vert]

I also ran catless with Roush mufflers, it's very loud. Cruising speed has some drone, but reasonable. During the winter, with cold pipes, it's very loud at start up. Accelerating from traffic lights is fun though, watching the cars next to you, roll up their windows, because they can't hear radio or the phone. At the track, they actually checked if I had cutouts, it was so loud at WOT...

I did have fun for the 2 months I ran mine without cats. If I stabbed the gas to raise the rpms up to 3500, it would scare people along the side of the road.