I currently have GT500 axlebacks on my 2012 GT. I'm considering putting a new H-pipe (which will use the stock cats) in to get a better sound. I know that the bigger diameter of the pipe should allow for better exhaust flow. In order to make that better exhaust flow useful, do I need to remove my resonators as well? Is it worth it if I'm not removing the cats?

 

I would remove the resonators. The stock H pipe is very restrictive, like 2" or 2.25" and the restriction doesn't end until after the resonators. I did a 3" Pypes X pipe and 3" tubing back eliminating the resonators and it really woke up my GT500 mufflers.

 

Good question. Removing the resonators will make it a little louder for sure, (there's a few videos around to demonstrate that), but I'm doubtful you'd see more power with the stock cats still being the major restriction.

An after-cat X-pipe is supposed to be worth maybe 3-4hp. Now how much of that is because it's a more efficient X, or because it eliminates the restricted section of the stock H?

I'd like to change out the mid and over axle pipes too, just because it bothers me knowing those reduced diameter sections are there. In reality though, the power they rob on a near stock car with the factory cats is probably negligible.

I doubt you'd be able to hear a difference just changing to a larger H section either.

Just my thoughts, no real experience to confirm.

 

I should meet up with you so I can hear the car.

 

Exhaust note isn't that important too me.

 

cuz you live in the no fun state

 

You crazy, this is the most fun state in the union.

 

The most restrictive and indecisive state in the union. For pot, against pot, for ghey marriage, against it. It's like trying to get Californians to make up their minds is almost as sound as Communism is good on paper. Seriously, wtf?

 

Did you keep your cats or what are you doing for emissions tests?

 

My cats are still there. I live in one of the two countys in Arizona that require emissions testing, but they only do an OBD compliance check so as long as I don't change anything to mess that up I'm good.

 

I'd like to hear your set up too. Do you hang with one of the local mustang clubs? There are a couple here and at least one does regular get togethers. I live west side.

On another note, I saw a clip of Heartthrob exhaust and they were claiming 4 hp from an x pipe cat back but 20+ from an h pipe cat back...Intresting...

 

+1 for gt500 axle backs minus resonators. Plenty if YouTube videos. I have no drone and sounds awesome.

 

Right? I have an axleback and i'm basically at the limit of exhaust mods.

 

I havent had time to hang out with the clubs down here. I would like to tho. I live on carefree and i17. I will be more west in a few weeks when my house is done (El Mirage Rd & 303).

 

Happy valley and i17 checking in with nothin to add, lol

 

https://www.youtube.com/watch?v=-t5e...e_gdata_player

 

I live off of El Mirage and T-Bird so not too far away. That new section of the 303 from I-17 west is very entertaining and lightly patrolled too.

 

sounds like we need to get the capt'n and go get steaks

 

If I get a new mid pipe and cut the resonators out, is that essentially an axle back unit, considering I have different mufflers?

 

You have an axle back if you change the mufflers. If you replace pipe from the cats all the way back to the end of the resonators, you would have a cat back system with the new mufflers. Your choice as to X or H for the mid pipe, and use at the least a 2.75 inch diameter pipe.