In changing out the stock mufflers on my '06 GT, I'm amazed to learn that the exhaust note without ANY mufflers is not nearly as loud or raspy as I imagined it would be. Now I'm seriously considering running straight pipes with tips and forgetting the axle-back muffs. But I'm concerned as to whether there would be negative consequences that I'm not aware of, such as loss of torque or horsepower, complications with the engine/computer, on & on. Am I wise to install mufflers even if I'm happy with the present sound? Are there any Ford warranty issues lurking here? Thanks in advance, guys.
Effect On Performance?
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How not loud? Like, "I could start this at midnight without waking up TOO many people" or "man, that thing's quiet compared to a 747"? 
I've been sitting on the SLP loudmouth fence so long me arse is startin' to hurt! I'd imagine yours'd be a tiny bit louder since apparently the slp's will do a BIT of muffling. Just trying to get as many opinions as possible since my GT is my only car and I'm still a little leery about effectively running straight pipes (with the cats of course)
I've been sitting on the SLP loudmouth fence so long me arse is startin' to hurt! I'd imagine yours'd be a tiny bit louder since apparently the slp's will do a BIT of muffling. Just trying to get as many opinions as possible since my GT is my only car and I'm still a little leery about effectively running straight pipes (with the cats of course)
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I haven't had any problems at all from mine.
As for performance, according to the tests done by MM&FF, they give you a LOT of hp and torque in the low end, but as the RPM's go up the gains drop off fast.
As for the sound, the SLP's don't do any muffling at all. They sound the same as removing the mufflers.
With the way the Mustang is engineered to rev up for a few seconds when it's first started and it's cold, the SLP's are "wake up the neighbors" loud.
The car has sort-of a race car sound to it.
You know the part near the beginning of Smokey & the Bandit where they've just left on their trip and the T/A does a burnout when the light turns green? That's exactly what it sounds like. (there's no telling what kind of car they used for the sound, but it wasn't a '77 T/A)
As for performance, according to the tests done by MM&FF, they give you a LOT of hp and torque in the low end, but as the RPM's go up the gains drop off fast.
As for the sound, the SLP's don't do any muffling at all. They sound the same as removing the mufflers.
With the way the Mustang is engineered to rev up for a few seconds when it's first started and it's cold, the SLP's are "wake up the neighbors" loud.
The car has sort-of a race car sound to it.
You know the part near the beginning of Smokey & the Bandit where they've just left on their trip and the T/A does a burnout when the light turns green? That's exactly what it sounds like. (there's no telling what kind of car they used for the sound, but it wasn't a '77 T/A)
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I am pleased with my SLP loudmouths..just the right tone I was looking for...they are quiet at cruizing speeds too.
SLP'S 05 Mustang
I have an 05' automatic Mustang GT Vert w/ the SLP Loudmouths. They drone a little loud inside at certain rpm's but it quickly goes away. On the highway after 70 mph they are barely noticable. I get so many compliments. It's pretty much as close to the sound of a 60's Stang as you can get. When you get on it, it's Nascar-like. It puts a smile on my face every time! To me , that's what it's all about. You don't want to be behind me at a launch. Most of the time I find myself turning off the radio just to listen to my car.:eyepoppin
I have an 05' automatic Mustang GT Vert w/ the SLP Loudmouths. They drone a little loud inside at certain rpm's but it quickly goes away. On the highway after 70 mph they are barely noticable. I get so many compliments. It's pretty much as close to the sound of a 60's Stang as you can get. When you get on it, it's Nascar-like. It puts a smile on my face every time! To me , that's what it's all about. You don't want to be behind me at a launch. Most of the time I find myself turning off the radio just to listen to my car.:eyepoppin
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I believe if you just have straight pipes you'll lose significant pressure in the engine and you'll run into some kinda problems in the longrun. I'd advise against.
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I disagree w/ twoscoops. If you run w/ no muffs, nothing serious will happen. You'll lose some power because of a lack of back pressure, but that's it. I had no muffs on my last Stang for over 2 years. Nothing happened. As far as warranty....who cares? I have Borla on my 05, and they have a million mile warranty...much better than Ford's. That's why I changed my ENTIRE exhaust...it has its own warranty, and Ford can't blame you for engine problems if you have aftermarket exahust.
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Burned valves
The only concerns that I know of, regarding engine damage, from exhaust stuff, comes from running without enough distance between your valves and the air. Like when people take off their ex. manifolds and start the engine. It is so loud, they think it would be cool to drive around a little, like that, to see what it sounds like. I heard the problem comes if too much oxygen gets in contact with your extremely hot valves, they can oxidize (burn) and then make very poor contact with their seats. I heard even stainless valves can oxidize, but I don't know what alloy stainless valves are made of so I can't comment on that. Some alloys will rust like you wouldn't believe. Many stainless alloys are magnetic, others cannot ever rust. Again I don't know what alloy SS valves are made of so...
Keep in mind, I have not ever run with super short headers or those stubby little race pipes or without my manifolds on, so have no actual experience.
Also never burned a valve.
-David
When I went down the straight, into work, once, I got on it, with the truck. 5500RPM in a 5.0L Ford, with straight pipes. A guy at work said it sounded like a fighter plane, from WWIIjlaw73 said:
The only concerns that I know of, regarding engine damage, from exhaust stuff, comes from running without enough distance between your valves and the air. Like when people take off their ex. manifolds and start the engine. It is so loud, they think it would be cool to drive around a little, like that, to see what it sounds like. I heard the problem comes if too much oxygen gets in contact with your extremely hot valves, they can oxidize (burn) and then make very poor contact with their seats. I heard even stainless valves can oxidize, but I don't know what alloy stainless valves are made of so I can't comment on that. Some alloys will rust like you wouldn't believe. Many stainless alloys are magnetic, others cannot ever rust. Again I don't know what alloy SS valves are made of so...
Keep in mind, I have not ever run with super short headers or those stubby little race pipes or without my manifolds on, so have no actual experience.
Also never burned a valve.
-David
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I'm gunna go ahead and retract what I previously said. There might not be any problems, but you probably will lose some power from the engine like fast05stang said. If that's the case seems kinda pointless to lose power for a diff exhaust note. Better off switching to axlebacks/cat-backs than nothing at all.fast05stang said:
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According to the dyno, you will lose 2-3 hp in the high RPM's, however, like I posted before, you will see a lot of hp and torque in the low RPM's. Try 20+ hp and 40+ ft-lbs of torque. To feel like a real muscle car, that's what the 4.6L needs. If you're only used to tiny motors that have to wind up to get any torque, it probably doesn't bother you. But for everyone else, like ex-5.0 owners it'll be a nice improvement.
it'll be a nice improvement.
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Found it.
http://forums.bradbarnett.net/index.php?showtopic=29901&hl=shootout
Be sure to read the whole thread to get the full and accurate story.
http://forums.bradbarnett.net/index.php?showtopic=29901&hl=shootout
Be sure to read the whole thread to get the full and accurate story.
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