Mudflap

I went to a local shop and had them bolt on the FRPP GT500 mufflers that they sell with the power packs. It took them about 45 minutes, they fought with the stock clamps, and then finally torched them off, lol. The new mufflers came with them anyway.

All in all, they are what I expected.

Sound level is slightly more than stock on idle, and under load. Cruising, they are just as quiet. Sound pitch is lower than stock notably, and they have a decent growl to them overall. These should have been factory equipment.

For what these cost, they aren't a bad addition. I wanted no drone to contend with, and these certainly do that. They are on the low end of "acceptable" to me personally in terms of loudness. I could go as much as 50% louder and still be fine. The tips fill out the rear nicely, and it definitely looks the part more vs the puny stock ones floating in the center of the large cutouts.

All in all, not a bad buy. I wanted the Roush units, but figured those were going to be too much volume-wise. I have tried 6 or 7 systems now from my 4 total 05+ Mustangs, and there is always a fine line between good-loud, and horrid drone. I have a Steeda CAI/tuner on the way, so that typically wakes up the exhaust note a bit too in past experience.

Soldier GT

I don't know man. You don't seem to happy with the setup..Think you might get another setup in the near future??

Thrashard340

Depends on where the OP draws the line between loudness vs drone vs cost. The GT500 AB's have absolutely zero drone. The only other AB's I have heard that did not have any drone were Borla's (the 50 state legal ones), but at almost twice the cost.

Mudflap

Well as I said, they were what I expected. The next poster hit it right on the head, the price of no drone but louder, is at least double what I paid for them. Therefore, like I said, for the money, these are a good addition.

Will I change them out eventually? I honestly don't know right now, maybe. I don't feel like dropping several hundred dollars, so these are a great/cheap replacement for the stockers for the time being. I know that these like any mufflers will likely have a bit of a break-in period at which point they are likely to get a little bit louder. I have 25 miles on them now, literally. So time will tell.

Thrashard340, what did that resonator delete do for them sound-wise? What was involved in that, and how much, etc??

BigDinTexas

I have to concur with Mudflap on almost every point he made about the FRPP GT500 axlebacks.. I love them for the fact there is ZERO, NADA, ZIP, ZILCH drone from them... Just wish they were louder, because I love the tone.

On a related note, there's someone near me who is selling a set of Roush axel backs... CL is here.


Don

danman0469

The Roush axlebacks really dont have any drone when cruising in 6th. They are waaay louder than i was expecting when you stomp it though. However, they sound fantastic, even with the loudness.

MrSandman

Have a shop cut out the resonators if you want a little more volume.

Don't take it to the shop that installed the mufflers through....the fact that they had to cut the hangers is a BIG red flag. I installed my on my back in 20 minutes.

Mudflap

They didnt cut the hangers, they cut the clamps because the new ones came with a new set anyway.

I had them remove the resonators today, sounds great!

1slov6stanguncc

how much louder is it without the resonators?

Mudflap

It is louder for sure, not by a ton though. I would say maybe... 25-30%? The change was mostly in tone. Adds a little bit of rasp while still being low and rumbly. Also, you get lots of cool pops and crackles on downshifting/decel. I would definitely recommend it. I made a thread specifically about the resonator removal:

https://mustangforums.com/forum/2005...-on-5-0-a.html