I dont know what to do here, I love the way the gt500 axle back sounds with no resonators but its just not loud and deep enough for me. I was thinking of a lethal performance off road h pipe to bump up the sound. Or should i just keep stock H and buy roush axle backs to get more sound... I HATE the clap clap clap sound i hear with some new mustang when they are taking off. My gt500's dont do that at all. I can handle a little rasp no problem tho. I want pretty **** loud. Opinions???

 

I have the gt500 with cat deletes. it definitely got noticeably louder . It still keeps that burble but just sounds meaner during acceleration. I still have my resonators too.

 

After reading over the post responses regarding the Borla S-type. I'll just add by stating that on the older 2005-10 (3) valve motors, the Borla S-types have a horrible drone to them, at least through my personal experience anyhow. As for the 2011-14, 5.0 Coyote motors are concerned? I don't really have much knowledge as far as how different the design changes are when compared with the older 2005-10 (3) valve motors. My guess is due to the exhaust valve changes between the 4.6 (3) valve and Coyote 5.0 4valve, the Coyote 4v motors are far less prone to interior resonance drone over the older 4.6 (3)valve motors. It would also be safe to assume that Borla also changed the interior design of their exhaust systems when being tuned for the 5.0 Coyote 4valve motors as well. At any rate, just saying

Edit: The post was intended to be submitted in the Looking To Change My Axle-Back Exhaust Again Thread. Anyhow, my bad lol.

 

I'm surprise their older design was that bad but there is zero drone on their coyote exhaust.

 

Yes indeed, the exhaust valve design on the older 4.6L 3 valves were that bad, but then again, so was their dreaded 2-piece designed spark plugs which were prone to breaking inside the heads lol. Anyhow the only exhaust kits to my knowledge that either reduce drone or eliminate it altogether on the older 2005-10 4.6L 3 valves, were from Corsa, Ford Racing FR500S and the old GTA mufflers. IIRC there were some owners that claimed they didn't experience any drone issues with the Borla ATAK axle back or from the Roush extreme cat back/mid muffler exhaust kits. However, according to each of the exhaust manufacturers, their exhaust systems are tuned specifically for the stock motor along with the stock catalyst system remaining in place. But once they're removed in favor of running an off-road setup, chances are you're going to end up experiencing cabin drone. At any rate, despite the drone issues I've experienced, I don't regret my decision in purchasing the Borla S-types for my particular application, as I really like the overall sound they produce along with their quality of workmanship/materials and most of all are backed by their million-mile warranty policy. In addition, Borla is shipping out 4 of their venturi inserts to place inside the exhaust pipes in which they claim will help in reducing interior resonance drone. Therefore I'm more than willing to give this a shot as a possible solution, as Borla is shipping them out free with no shipping costs involved whatsoever. Needless to say, you certainly can't beat an offer like that, that's for sure

 

The stock h pipe is very restrictive. Install the O/R h pipe and your GT 500's will really wake up. Just don't forget the tune that goes with removing the cats.

 

hmmmm, really? where is that coming from? I have read just the opposite; removing the cats is supposedly worth only a couple HP . . . did you do it on your car, any chance you have a before and after dyno run? (would be great to put some facts on it)

 

Actually, the stock catted H is very efficient flowing when compared to the previous SN-95 gen cars. IIRC the stock cats have between 400-600 cells per square inch, where high-flow cats have between 200-300 cells per square inch. That being said, installing an O/R h/x pipe is good for just increasing sound and eliminating back pressure.

100% spot on

 

No dyno runs, but I replaced my H with a 3" X. The stock H starts at 3 inch and necks down by a quarter inch or so three times and I couldn't put my thumb into the crossover, It doesn't flare back to 2 3/4' until after the resonators. I call that restrictive compared to a full three inch X or H pipe. My car sounds deep and throaty but not too loud or obnoxious.

 

I will second this, even without resonators I have zero drone