[GreyGhost702]

Originally Posted by dmcmahan60

Update, I removed the Speed Engineering 3 inch x pipe and put the stock x pipe with the scondary cats on it. Made a huge different and I can tolerate it at this point. will stll add some resonators where the crush part is and go from there. Oh yeah and I kept hearing a rattling sound all the time. So where the muffler shop owner took of the crap x pipe he found 2 header bolts lodged near the collector on the drivers side where all 4 of them come together!@#$%$#@!

I love it when people jump on the "You get what you pay for" band wagon. Because reputable shops and major brands never screw up, right? Even Magnaflow has had its share of product flaws, crap the slips passed QC, and a customer service rep having a bad day. People who believe in that mantra should shop at The Good Feet Store and cancel their Sams/Costco memberships, and send me their monthly disposable income.

It sounds like your exhaust shop isn't helping the cause. That's pretty bad form if they're finding header bolts in the collector when they should be fastening the headers to the heads. Hopefully they're providing you excellent customer service at this point, one would think they would want to preserve what reputation they have left and turn this into a positive customer experience. Like others have recommended, the muffler is going to control most of your volume. If you want to turn it up & down, you'll need something NPP. Otherwise there's no telling what kind of exhaust note you'll end up with just adding other mufflers/resonators to the system. By far the best way to take the bite out, will be putting an appropriate high flow cat after the collectors. I can't say I have particularly high faith in one brand or another, I have seen kooks eat shit along side magnaflows and ARH cats. A big factor comes back to the tune, and ultimately power level. Beyond 800hp, even a good cat is going to have a shorter lifespan than normal. IMO you'll need tune refinement whether you add or remove cats. There are things you can get away with without a cat, that you can't with a cat. Even then, unreasonably high EGT's can cause other damage and you really shouldn't be running that hot if the tune is spot on.

IMO don't mess with swapping mid pipes and resonators. Have the exhaust shop straighten out what they're responsible for, and find a high flow cat the fits your power level and budget. Have the exhaust shop make the appropriate installation for your needs. Remember that you can also stack cats, one after the other. If emissions inspections aren't an issue, I recommend V-banding them so they can be bypassed/replaced as needed.

I did headers and am catless for the time being, but I went with Stainless Works Redline series NPP. It was the more affordable of the NPP mufflers that had the tone I liked. Valve open it's ridiculously loud. Valve closed it's just slightly louder than totally stock with the valve open. But that's my ear, I wish I had done a decibel meter before/after for data purposes. But I love my exhaust. Can't wait to hear it chop open valved. Keep us updated.

[dmcmahan60]

Grey, thanks for the reply but it was not a muffler shop that did this but supposedly a reputable Performance shop. There were red flags from the first day when there were things left off of the engine compartment the first time I tried to pick it up.
Got a few miles from the shop and was told it is probably a bad spark plug, then when I got it home and on a rack the crap show started from there. Broken header bolt in the head, and their excuse was oh yeah we were going to tell you about that but we tightened the rest of the bolts really good:( And it went downhill after that. Took the car back to them so they could make it right and for the most part they did. But all in all it was a horrible experience and will never trust them again!

[Smokin19]

I have gone back to the stock suitcase from the AWE Touring axleback. Maybe it was because of my build (see below) that it was so loud but, now it seems just right with stock and the NPP. Must be an age thing LOL.

[dmcmahan60]

Originally Posted by Smokin19

I have gone back to the stock suitcase from the AWE Touring axleback. Maybe it was because of my build (see below) that it was so loud but, now it seems just right with stock and the NPP. Must be an age thing LOL.

Lol, I am 57 and don't do loud and raspy anymore. When people roll their windows up when you pass them, then that was just too much. Plus the cold start at 4:15 am the neighbors probably did not like too much:(

[GreyGhost702]

Originally Posted by dmcmahan60

Grey, thanks for the reply but it was not a muffler shop that did this but supposedly a reputable Performance shop. There were red flags from the first day when there were things left off of the engine compartment the first time I tried to pick it up.
Got a few miles from the shop and was told it is probably a bad spark plug, then when I got it home and on a rack the crap show started from there. Broken header bolt in the head, and their excuse was oh yeah we were going to tell you about that but we tightened the rest of the bolts really good:( And it went downhill after that. Took the car back to them so they could make it right and for the most part they did. But all in all it was a horrible experience and will never trust them again!

That’s nuts. Most likely broke off that bolt with a power tool. The header bolts are what, 20ft/lbs? Probably zipping around with power tools and cross threaded it and snapped it off. Those bolts aren’t exactly frail, and the heads are aluminum. So much fail right there. And then compensating by torquing the remaining bolts higher than spec? I trust a Walmart lube tech more at that point. They should pay to let a real shop fix their shit.

If you can swing it, the stainless works Legend series would probably be right up your alley. While the stock NPP definitely has hush power, the stock unit has been known to develop issues with internal rattling and such, I kind of lean on the extra heat and harmonics wearing it out faster. Not to say aftermarket will out last OEM but, it does sound like you need volume you can control. I have been considering doing a custom H pipe for the mid crossover. Removes a lot of rasp and keeps the thump deep. Rob a little power? Maybe.

[dmcmahan60]

Today I am going to have 10 inch long resonators put on where the crush section is under the rear cradle. It is sounding better with the stock x pipe back on it and the secondary cats in place. The resonators should do the trick. Will update later. I have refrained from bashing them on social media but will never recommend them to anybody in the car community where I live. And if asked will tell them the story why.

Update: the 10 inch resonators installed where the crush sections were seem to have helped a lot. I can tolerate a little bit loud at WOT and at regular highway speeds you can hardly tell. I enjoy driving my car again. Thanks for the feedback all. Good day.