Refining the best sounding Exhaust (Duals)
So my mustang had the stock exhaust for a while and then I did a GT500 muffler swap in the rear and had a super nice tone but didn't have the volume I wanted. I rolled with it for a while and found some pacesetter shorty headers and threw those on (and deleted the EGR after it pissed me off -haha) and it sounded AMAZING! I loved the tone it was just about perfect, and the volume was a bit better at the top but I still want my car to be heard just cruising through the city at lower speeds or just idling. (I know, kind of a ricer mentality but hey I'm young and just wanna be obnoxious for a little bit and later tame it down.)
Later down the road found a sick deal on CL real close to me on a full exhaust for a 2011 GT mustang. Cats, down to the H pip, and the GT Mufflers with nice huge chrome tips that fit perfectly with my new body kit. So I couldn't turn that down for 80$ and when my friend and I got to mocking it up, it was all pretty much the same. I don't know the exact sizing of the pipes but it's much bigger. Fabed some rear hangers for the mufflers and the ones that go on the tranny support and it lined up super nice. the cats obviously wont bolt up the Shorty Headers I have because the new exhaust connectors aren't the ball-and-socket style that the 05-09 exhaust set ups come with.
So, to tackle this what I should have done was unbolted the new GT cats and cut my cats off to plug them back in and weld it after the stock V6 cats and before the H pipe.
I had the bright idea that while I'm at it I should take out my cats because I live in MI so I never have vehicle inspections and all my life I have had huge benefits removing cats from my 'sports' cars. Also have a tuner so wasn't worried about throwing codes. And, I now run racing fuel 110oct with nitrous shot occasionally and would like to still have this as an option and I've heard that cats won't last long with this going through them. My car had 125k miles on it and from what I could see the cats looked really good still.(no damage, and clean inside). So I welded in a pipe to delete the cats, bolted the original flanges off the headers and then welded the new cat delete pipes into the H pipe and so on.
I think it flows a little better on the top end (my butt dyno said so lol) and I love having a dual exhaust, the tips are my favorite.. they're big and smoke comes out of both when it's cold but... at 3,000 RPM... it does the god-awful thing many people have ran into with the 4.0 mustangs and removing cats... it sounds straight Honda. If you really get on it and go all out it sounds pretty cool, but from 3-5 grand it's kind of embarrassing. So I'm stuck granny shifting around just before the "trumpeting" noise unless I have room to really give it the beans.
Any tips on a fix? I'd rather not re cut and re put my cats back it.. it just feels wrong. I still have the GT cats, or HI flow ones may be an option, but I heard those can make the trumpeting too. Would fabbing in resonators about halfway through the exhaust system help at all? There isn't any drone and it's honestly not that loud so I'm worried this will just silence it. Some people have recommended that to me and to offset them to make it rumble a bit more. This is an option.. there's a pair of SLP loudmouth resonators for sale on my local CR for 50$. (I REALLY like used parts haha).
I could remove the GT mufflers and just see what it sounds like straight piped but I think I would need more support to hang it and not having tips out the back would bother me.
I could buy aftermarket mufflers (axle back) for a 2011 mustang but they are pricey (even used) and I don't even know if that would help or hurt my trumpeting noise.
Long story short I am gathering parts up to most likely do a 4.6 swap, (and don't give the sell it and buy a v8, I've already done plenty of swaps and am sick of blowing transmissions from the 4.0, along with I think I'm pretty maxed on this engines potential. It's been fun and I'll keep it for probably this winter and maybe next summer but then I should be ready to get to work on that from a donor car.)
So, I have heard from one person that with my shorty headers I can buy a full exhaust that is for a 4.6 (cats all the way back) which I would like because that's one less part for me to worry about when that time comes. Is this true? Or how else would anyone recommend to make my car sound louder with less rice trumpeting that won't put my back money wise or I am willing to spend a bit if it will be compatible with my future 4.6 set up.... if that all makes sense.. appreciate the help guys!
2005 Legend Lime 4.0 5Speed
Drivetrain: K&N Drop-in, LUK clutch, GT mufflers, BBK 70mm TB, EGR Delete, PaceSetter Shorty Headers, Diablosport 93 Tune, Vex nitrous kit, 7.5 rear t-lok and 4.10 gears (8.8 rear soon)
Suspension: GT500 shocks/struts, Eibach Springs, GT500 Rear Control arms, Steeda strut bar
Cosmetics: Louvers, GT spoiler, GT black wheels with chrome lip, eleanor bumper, gt500 shift knob, GT grill with fogs, 3D carbon side skirts & rear diffuser/skirt