Chuck's Black GTO

Hello,

I just got an 04 M6 leftover about a month ago and love it, but would like the exhaust note to be louder. I'm considering the SLP Loudmouth, but I'm not sure about highway cruising. I want to be able to hear the radio while cruising up to 70mph, but I want to hear that classic V8 roar when I get on it as the revs build up. I'm thinking I can get away with the Loudmouth, since the reves are so low in 6th on the highway. Anyone with an M6 car have some experience with the SLP system?

Brodkill

iTrader: (1)

No exp on a GTO, but my friends SS is pretty damn loud with it on his car....

CHarris

iTrader: (5)

The more mods you do and the more horsepower you make the louder the loud mouth becomes. A lot of guys like it on relatively stock cars (speaking of friends who had it on F-bodies) but it gets too loud for a lot of people when they start putting down real power. Like "LOOK AT ME MR. POLICEMAN!!!" loud as you go through the gears quickly

Cory

LS2 Pontiac GTO

They dont call it loudmouth for nothing

Xsta Z 28

iTrader: (2)

I've never liked the loud mouth . . . .

OOsilverado

I like the way it sounds, we have it on my girlfriends GTO and it sounds great, its loud. The resonance inside is a little on the loud side but i dont think its annoying, but thats a personal opinion though.

CMNTMXR57

Comparing the loudmouth on the F-Body's to the Loudmouth on the GTO despite the same motor is not exactly a scientific means of analogy.

They don't call it a Loudmouth for nothing is true, but they have distinctly different tones between each car. A Loudmouth on the F-Body's is very raspy and very loud. The Loudmouth on the GTO is plenty loud without as much rasp (providing you still are running cats at the minimum and resonators (if you have the stock cat-forward).

Do a search, some sound clips of mine are around here in this section. To sum it up, I had to put the cats back in to quiet it down to acceptable levels.

onyx_rock

iTrader: (8)

I have it and I will tell you that it if you want it louder this exhaust will work for you. It is not the most refined sounding exhaust I've ever heard. My GMMG on my TA sounds 10x better. The LM sounds more like a open cutout. My GTO gets so many more looks now though with it on. People are probably like

"why is that Grand Am so loud"

On a serious note, it has made driving the car much more fun.

CHarris

iTrader: (5)

So the differential in "rasp" aside they are comparatively LOUD Actually, anytime you take the cats out of anything it gets raspy as a standard.

Cory

LS2 Pontiac GTO

To me the best sounding exhaust systems are the corsa and borla.

ronaldvetteron

I have the CORSA Sport (oval tip) on my 2004 GTO. I really like the sound. It is not shy but 0 interior resonance at any speed! We have a CORSA on our son's 2004 Silverado 5.3l (smaller bore LS1, essentially) and it sounds about identical to the CORSA on the GTO. He also has 0 interior resonance yet it is very healthy sounding. CORSA and Borla are around the same price if you shop around. CORSA is officially recognized by GM, by the way. And, while it is not a big deal it reduces even further any chance of hassle from a dealer when warranty questions may arise.

Rob

iTrader: (6)

If you want it louder, get long tube headers. I still have my stock cat back and it sounds great with the dynatechs and cats. Its deeper and slightly louder, especially at WOT. But cruising, its almost stock like.

Plus you will pick up a ton more HP/TQ with a header change than a cat back change.

Chuck's Black GTO

Thanks for all the advice. One thing I forgot to mention. I live in central PA, and we have emmissions inspection. Because of this I'm not going to do anything with headers or the cats. I'll probably just put a K&N filter in it, and a cat back.

Chuck

Brodkill

iTrader: (1)

I live in pa, and for emissions all they do is scan for codes anymore from what I've read and been told, you can put LTs on with cats and pass with no problems what so ever, my car passed with headers...

CMNTMXR57

The sky is the limit now with scan testing. Anything AFTER the post cat o2 sensor is NOT an emissions device and will not affect emissions. It is purely a noise abatement device at that point in time.

Emissions testing your car isn't the torment it once was. With LT headers, all you have to do is relocate your post cat O2 sensors (further down) after the cats physically and make sure they light off and switch normally with the PCM in conjunction with the front (Pre-cat) O2 sensors, therefore not generating a DTC.

If you go with an off-road pipe (eliminating the cats altogether), you either have to turn the post cat O2's off with/by a tuner or install a set of O2 simms that trick the PCM into thinking the post cat O2 sensors are there and operating normally. Unless you remove your cats and they do a visual inspection, you have nothing to worry about.

I've passed Illinois's OBDII scan test twice with a heads, cammed, headered, etc Camaro with nary a problem. 5 minutes and you're done! Many guys with bigger, more powerful combinations pass all the time with this type of testing.

It's all in the tuning! There really is nothing to worry about.

2000LS1Z28

The SLP Loudmouth to me sounds very racey and highpitched on the GTO when you get into the throttle...Super LOUD too! I've actually heard it in person and it was also fairly raspy as well (but I'm guessing the one I heard had headers/no cats too).

Remember, loud doesn't always = good

Mike

CMNTMXR57

Where did you hear it Mike. I bet it was my car. Was it Impulse Blue?

2000LS1Z28

Yes, it was Impulse Blue! It was at Speed Inc during some GTO dyno day or something back during late October or early November I think...I was there because my friend was getting his black LS1 Formula dynoed too...But that thing was LOUD when the driver got on it after pulling out of their parking lot! Was that you?!

SuperSporttruck

iTrader: (2)

I put a slp loud mouth & bassani X sysyem on my buddies 03 cobra and it almost sounds uncorked to me when he is at WOT. I think it sounds sweet but he doesn't drive that car everyday.

JETNITRO

I just put the speedbuilt banshee duel exit on my gto and it was about the same at idle but once you get the rpms up a little you can really hear a nice deep tone differrence.

I'm really happy with it and the stainless tips a really nice too. Last week I just put a set of kooks headers on as well ...it freakin sounds incredible now huge difference very good quality!!