Bought a used 2014 Mustang GT a few months ago. The car already had some exhaust modifications. It has the factory manifolds, but some unknown brand of H-pipe with some high flow cats (I guess). It had the resonators removed and had 40 series Flowmaster mufflers. I was not crazy about the sound, so I opted for a set of RTR competition axle backs. A few days before they arrived a rattle started coming from under the car during cold starts. I figured it was something with the exhaust so when my new RTR's showed up and I brought the car to the muffler shop, I asked the tech to check it out. He took a rubber mallet to it and found the passenger side cat had something loose in it. He said that I needed to get that fixed asap. Anyway, I left the shop and loved the way the RTR's sound. A few days later I went to the speed shop to make an appointment to get my car dyno tuned and asked about the rattling cat. They also said I need to fix it asap. They recommended the Pypes offroad H-pipe, so I ordered it and made the install and dyno appointment. So the appointment day arrives, the new H-pipe (and MGW shifter!) is installed, and the car is dyno tuned. I pick the car up and notice the sound is now way different. It is much louder, too loud now lol. But that is not really a bad thing. The thing that is bad is when you engine brake the car, or say, let off the gas when you have it in gear and the revs drop. Well now the car sounds like an 18 wheeler doing a jake brake lol! It just sound terrible to me. It doesn't even have to be at a high rpm. It'll do it at 3000 rpm and up. No popping or rasp, just the sound of a huge fart dropping in tone as the revs drop lol.
So now the question is, what do I do about it? I have a few ideas:
1. Purchase a new H-pipe with cats (very costly)
2. Purchase a used set of GT500 mufflers and just sell the awesome RTR's.
3. Make an attempt to rid the jake brake effect and install some type of muffler where the resonators where, like a pair of Dynomax race bullets. These can be purchase for about $100 a pair.
Do you think option 3 will get rid of the annoying de-rev sound? I know it will tone down the volume a bit, but no idea if it will eliminate the jake brake effect. Anyone had this annoying de-rev I am talking about?
BTW now that the old H-pipe is out you can clearly see the broken part inside of the passenger side cat. Car runs good and pulls a little harder. The MGW shifter is great!
So now the question is, what do I do about it? I have a few ideas:
1. Purchase a new H-pipe with cats (very costly)
2. Purchase a used set of GT500 mufflers and just sell the awesome RTR's.
3. Make an attempt to rid the jake brake effect and install some type of muffler where the resonators where, like a pair of Dynomax race bullets. These can be purchase for about $100 a pair.
Do you think option 3 will get rid of the annoying de-rev sound? I know it will tone down the volume a bit, but no idea if it will eliminate the jake brake effect. Anyone had this annoying de-rev I am talking about?
BTW now that the old H-pipe is out you can clearly see the broken part inside of the passenger side cat. Car runs good and pulls a little harder. The MGW shifter is great!
