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I need a more versatile exhaust system.

2K views 23 replies 6 participants last post by  07gtspyder 
#1 ·
Hello, 4th gen fans.

I bought my first eclipse, a 2009 GT Spyder, just 3 months ago. I really like the car overall, but I need to do something about the exhaust. I don't know whether the exhaust I have is stock or not, but it does some pretty annoying, loud droning in the 1800 - 2700 RPM neighborhood. Mine is an automatic with the 5-speed Sportronic setup (which I really like). In Sport (auto-manual) mode, if I keep the RPM's around 3000, it's actually pretty quiet. At 4,000 and higher, it sounds really good all the way to redline, as though my exhaust system was tuned to perform in that range. So the first question is, does what I'm describing sound like what I should expect from a stock, OEM exhaust system? (I've never heard one of these with a stock setup for comparison.) And second, if this is what stock is supposed to sound like, I want to switch it out for something that sounds better at lower RPM's, ideally somewhat deep and throaty. Or even just something that was quiet with correct back pressure in that lower RPM range would be OK. I feel like just switching out the mufflers will do the trick, so can someone recommend a set of mufflers that will behave how I want?

Side note: It's mostly my wife that is driving my queries; she prefers me just keeping it in regular Drive mode--not Sport mode. Therefore, the engine usually runs in the droning RPM range, and she complains about it. When I put it in Sport mode and drive it hard, she feels like I'm going to wreck it and kill us both.

Any help, ideas, discussion, brainstorming, etc. is appreciated. Thanks, all.

-NateDawg875
 
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#2 ·
The exhaust wasn't "tuned" for higher rpm. That shift from 3k rpm to 4k rpm is mivec kicking in. If the exhaust is droning that bad its probably aftermarket. Maybe a resonator delete or something. Hard to say without pictures. As for the low rpm vs high rpm issue, you're not changing that without either a tune or different cams.
 
#3 ·
I agree, most likely an aftermarket kit. Take a couple pics and we'll be able to tell you. Try and get a picture of the muffler, mainly the boxy housing and any branding on the tip you may find. Try and get a picture of the main pipe under the car too, mostly the catalytic converter (humpy/thick) portion and/or where it bolts up to the bendy portions of the exhaust coming over the subframe. If we can ID any branding, sizing, or compare it to what we know OEM looks like we'll help you out.

For what its worth, the OEM exhaust is pretty quiet but rumbles a tiny bit on start up to let you know you have the GT. It is quite pleasant and unobtrusive though. For comparison, I have headers and the Injen kit and I got pretty tired of it when I had to daily it. It's obnoxious to the point I wince and cross my fingers every time a LEO pulls up to an intersection with me.
 
#4 ·
1: Like has been said, you're feeling and hearing MIVEC kick around 4000rpm. Your car most likely doesn't have a tune either. Tuned properly, you don't get that kick because it comes on at a better time to keep the power curve smooth, without dropping off first

2: Stock exhaust doesn't drone at all. Thin stainless piping like an eBay exhaust drones like crazy, as does not having a resonator up front or cats.

3: I like Magnaflow turbo mufflers. They give a deep sound, and flow plenty. If you're doing dual, a pair of 2.25" are plenty.

4: Back-pressure is a myth that needs to die. It's exhaust scavenging that matters, which in short, is that each exhaust pulse drags out the next. It can only be tuned to a specific range, however, so you need to decide where you want peak efficiency. Exhaust pulse volume and overlap affect it, but in short, a 2.75" exhaust on a GT is a good street setup (can Y to dual 2" or greater if you'd like, just don't shrink the total exposed surface area of the pipe opening. Single 2.75 is 5.94, dual 2" is 6.28. No common pipe works that is smaller)
 
#5 ·
Thanks, everyone, for chiming in. This is helpful. At the moment, I'm actually recovering from an abdominal surgery, so it will be a few weeks before it's a good idea for me to be climbing around and crawling under cars, wrenching, etc. But when I can again, I'll be under my GT trying to ID stuff.

And if anyone else has anything to add, I'll be interested.
 
#8 ·
OK, I'm back--finally. I was able to get under my Spyder and snap some photos. Tell me what you think: stock exhaust parts or something else? Also, you'll notice my exhaust is kind of rusty and crusty. I would have thought the 2009's started life with stainless steel, and so would be in nicer shape, even with some age and miles. Any thoughts on that?

Thanks

P.S. A couple more photos are coming; I was only able to attach 10 to this post. Tire Wheel Vehicle Automotive lighting Automotive tire
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Automotive tire Tire Tread Wheel Wood
Wood Bumper Automotive tire Automotive exterior Gas
Automotive exterior Bumper Wood Gas Tints and shades
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Tire Automotive lighting Automotive tire Wheel Car
Hood Automotive lighting Automotive tire Bumper Automotive exterior
Automotive tire Hood Automotive lighting Automotive exhaust Tread
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#11 ·
OK, I'm back--finally. I was able to get under my Spyder and snap some photos. Tell me what you think: stock exhaust parts or something else? Also, you'll notice my exhaust is kind of rusty and crusty. I would have thought the 2009's started life with stainless steel, and so would be in nicer shape, even with some age and miles. Any thoughts on that?

Thanks

P.S. A couple more photos are coming; I was only able to attach 10 to this post. View attachment 103674 View attachment 103675 View attachment 103676 View attachment 103677 View attachment 103678 View attachment 103679 View attachment 103680 View attachment 103681 View attachment 103682 View attachment 103683
That’s a nice northern patina! That drone is definitely coming from the muffler if you check out you tube vids it’s pretty common. The drone went away when I put in the air intake but I’m almost positive just swapping mufflers will work 100% this was my experience exactly. And my exhaust shares the same patina no drone anymore just blasting a wonderful sound from from a flowmaster fx straight through glass pack type deal!
 
#12 ·
Thanks again for the info.

First, a consensus is forming that my exhaust is indeed stock. Does anyone disagree?

Second, 07gtspyder says he is happy with his Flowmaster FX unit, which I am considering. Does anyone have any other muffler replacement suggestions? Being an '09, mine does have the dual setup. I'll be looking for something that will scavenge right, with maybe some aggression in the sound, but not extreme.

What I plan to do before starting to take anything apart is get under it and see if I can detect any leakage upstream of the mufflers. If I don't find any, I'll probably just go ahead with muffler replacement.
 
#14 ·
Thanks again for the info.

First, a consensus is forming that my exhaust is indeed stock. Does anyone disagree?

Second, 07gtspyder says he is happy with his Flowmaster FX unit, which I am considering. Does anyone have any other muffler replacement suggestions? Being an '09, mine does have the dual setup. I'll be looking for something that will scavenge right, with maybe some aggression in the sound, but not extreme.

What I plan to do before starting to take anything apart is get under it and see if I can detect any leakage upstream of the mufflers. If I don't find any, I'll probably just go ahead with muffler replacement.
 
#16 ·
I'm zeroing in on some Thrush Welded Series mufflers, but I'm thinking there are some sizing considerations, because I do want to maintain decent scavenging. The inlet OD's for mine are just a shade under 2 inches diameter. This is my first go at putting aftermarket (non-OEM replacement) exhaust on a car. I might do it myself, but I might hire it out. If I'm doing it, it looks like I'll be cutting and adapting to fit the Thrush inlets. The closest inlet size Thrush has to 2" is 2.25", and those are all also 2.25" outlet diameter, according to Thrush's website. They do also have 2.5" and 3" inlet and outlet sizing. Thrush's muffler body length is available in 13" or 17", so I'm thinking that has to be 13". So now I'm looking for advice on where the best place to cut is, the smartest inlet/outlet sizing, adapting hardware, and anything else I need to think about as I get into this.

Thanks again to anyone who can share some wisdom.
 
#18 ·
By the time you're at the mufflers, if you're worried about scavenging you have to account for how much the exhaust cooled along the way and velocity lost as well.

If you need to use the mufflers to cause back pressure to try and get some scavenging effect, you've gone too big on the pipe.
 
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