My opinion on deleting the resonator

[jmiska]

The stock resonator on my car had developed an annoying buzz and a small leak so it had to go. I read all the old threads on here regarding removal of the resonator and replacement with a glass pack, vs. straight pipe, and all the differing opinions on sound.

Well, today, I'd had enough, and swung by my local muffler shop to just have the stupid thing cut out and a 2.5" straight stainless pipe welded in. I figured if it's horrible, I can section that pipe and add a glass pack, and I wouldn't have lost much, anyway, as pipe work would be needed to adapt a shorter glass pack to the space where the resonator used to be, regardless.

So far, I'm perfectly happy with the sound with no resonator. For anyone with a bad resonator and considering just dumping it, here is my assessment of what to expect with stock mufflers, for what it's worth.

I have a more or less stock 2005 GTP with a slightly upgraded cam and a ZZP 3" catted downpipe. Stock exhaust manifolds and mufflers.

With a 2.5" pipe in place of the resonator, idle sounds exactly the same. Mid throttle pulls are very slightly louder with a tiny bit more exhaust roar, but it's a decent sounding roar (not raspy or grating). Full throttle pulls sound noticeably better, with a nice deep roar out the back, but the engine and supercharger are still the most prominent sound. Highway cruising at 2000 RPM is the only downside, but it's not a big one. There is a subtle, not too attractive drone at the back, but it's not loud, and is nothing compared to the tires and wind at that speed. Between the three different main sounds at that speed it's still the slightest, by far. I was worried about ugly raspiness, but there really isn't any at all. It pops and burbles more when closing the throttle hard in a low gear, but to me that sounds just fine.

I have no idea how the 3" downpipe affected my results with no resonator, as that was already done, but, for the future, when someone is considering exhaust changes, these were my results with that combination. Overall I'm happy with it and figure I'll keep it this way for now.

[Fivefingerdeathpunch]

The cat and stock mufflers are what help keep the rasp away.

I too see no problem with removing the stock resonator if the factory mufflers are there.

[Bronco Boy]

The cat and stock mufflers are what help keep the rasp away.

I too see no problem with removing the stock resonator if the factory mufflers are there.

^ This. Been there, done that.

[jmiska]

It seems to me that the stock mufflers are just fine, and from everything I've read and heard, unless you're looking to make 350+ wheel horespower, they're not a restriction. If you are making that much horsepower, you're probably not too concerned with daily, around-town exhaust sound, anyway. If you're not making that kind of horsepower, there's also no good reason to remove the cat.

[markpa]

Have someone else drive it and stand behind it as they take off up a hill. See if you feel the same way. Sounds like a wet fart.


Sent from my iPhone using Tapatalk

[waupachino]

My GTP has no Cat, and I can tell you this much, without the Resonator the drone inside the car is so bad it would drown out the stock radio. With no Cat, and Resonator with stock Mufflers the car has a nice tone and no drone. It really comes down to personal preference on what sound you want out of your car.

[bonerjamz03]

Have someone else drive it and stand behind it as they take off up a hill. See if you feel the same way. Sounds like a wet fart.

I had a straight pipe in place of resonator until a buddy of mine borrowed the car and I heard it as he was driving away. Was horrific from the outside. Needless to say I had a glasspack welded in shortly thereafter.

[jmiska]

So with the comments about sounding like a wet fart, I was concerned that the car sounded very different from the outside than inside. Inside, I was perfectly happy with the sound. There's a slight resonance at about 1900 RPM and light throttle that's not great sounding, but it's pretty quiet and not an issue. Otherwise, I felt the car sounded better than stock, particularly at anything more than half throttle, and especially at full throttle. I had a friend drive it quite a lot today under hard and light acceleration driving away from me, and it sounded fine. In fact, in most ways, I felt it sounded pretty good, and, again, better than stock. It has a crisp, fairly harsh but clean sound out the pipes. It's clearly not a V8, but it sounds like a good six running high cylinder pressure, which is just what it is. I don't want it to sound like a V8. I have a nice sounding truck I can use if I miss that sound.

So, overall, I'll stand by my assessment that a 3" downpipe and cat, with a 2.5" straight intermediate pipe, into stock mufflers sounds good on a GTP.

[waupachino]

I think having the cat on yours is the main difference compared to mine. I'd be curious how many of the others that commented still have the cat installed.

[Bronco Boy]

When I bought my GP, it had no resonator, a small universal cat and stock rusty mufflers. Sounded pretty good.

A year later I installed a Walker (stock) cat to pass the smog test. Nothing changed except I now passed the smog test.

Three years later I installed Borla Pro XS mufflers. The sound was good, but the drone was off the charts.

A few weeks later I installed a Walker (stock) resonator. The sound was great and the drone was gone.

Over the past few years, I've found that the Borla's are a little loud for this old guy, but they do sound good. If I had to do it again, I would put stock mufflers back on, but only because I'm passed the "loud exhaust is cool" stage of life and would prefer it a little quieter.