How do I rid the raspy sound of Loudmouth around 2200 RPM?

**02SS35th** · 02-21-2011, 01:42 PM

I've owned an an '02 SS 35th for a little over a year now, and had a loudmouth exhaust put on the car. I didn't even notice I had Hooker Longtubes on the car until afterwards along with a cat delete. Don't get me wrong, I love how loud it is, but the raspy sound at around 2200 RPM has to go. I've read several solutions to this as to get rid of the loudmouth and put on a catback (Even though it had a Magnaflow on it before I put on the Loudmouth and I still heard a little rasp in that even) or put on some High Flow cats. I did purchase http://cgi.ebay.com/ebaymotors/ws/eB...8162&viewitem= these 3" high flow stainless steel cats since they were only 38 bucks each, and read many great things about how not to spend 500 bucks on a pair of high flow cats otherwise. I suppose what I'm looking for is some second opinions. Did I do the right thing by purchasing high flow cats to rid the raspy sound, but still continue to be loud? Should I have put on a loudmouth II or different muffler and still left the cats off? The goal is, loud as possible, but minus the raspy sound. Thanks!

**KMdef9** · 02-21-2011, 03:23 PM

Ditch the LM, buy a magnaflow.

If not, you could get some high flow cats.

**35th-ANV-SS** · 02-21-2011, 03:36 PM

Mine does the same thing at the same RPM and I have the SLP LM II, Kooks LTs and ORY with no cats.

I've read the same thing. Cats help with the rasp/drone.

**02SS35th** · 02-21-2011, 03:49 PM

Alright, excellent. Thanks for the responses. Yeah, I love the Loudmouth on WOT and even idle. It's perfect, it's just that rasp around that low RPM range that I want to get rid of and it will be amazing. The Magnaflow system that was on the car when I first bought it even had that same rasp at the same RPM. It just wasn't near as loud due to the fact of the muffler. These new high flow cats should ship here in a couple days and I'll have a shop put them on. I'll post the results on the sound and possibly a clip!

**35th-ANV-SS** · 02-21-2011, 05:19 PM

Sounds good. I'm interested in the sound difference myself.

**Mike0202** · 02-22-2011, 10:30 AM

I will be running Pacesetter Long tubes, Texas speed Y, Magnaflow high flow cats to an Slp Loudmouth in the spring time. Ill let you know how much the cats tame it down.

Someone else said magnaflow but on a stock internal car it really doesnt sound mean at all.

**Deezl SS** · 02-22-2011, 10:43 AM

I run ebay headers, high flow cats in a 3" y and put a magnaflow muffler in place of the LM1 resonator and don't have the rasp.

**02SS35th** · 02-24-2011, 10:55 PM

Yeah, when I first purchased my car, it had a Magnaflow setup into a quad tip CME setup. With just the hooker longtubes, cat delete, and that exhaust, it still got a minor rasp at 2200 RPM. Wasn't near as noticeable since it was quieter. I will admit the system did sound great, but looking at the custom build of the pipes, it looked very restrictive. Worst comes to worst, if I'm still getting a rasp after adding the high flow cats, I'll look into ditching the LM for a bullet muffler or something else if need be. I think the cats will solve the problem I'm looking for, but still keep the same loud and mean tone. I'm unsure of what my Y pipe is, but I know for a fact it isn't stock.

**Smittro** · 02-25-2011, 03:36 AM

I agree with the high flow cat/s..

Definetly will help to defuse the exhaust before it gets to the muffler/s..

**pewterzron** · 02-25-2011, 06:01 AM

Originally Posted by 02SS35th

Yeah, when I first purchased my car, it had a Magnaflow setup into a quad tip CME setup. With just the hooker longtubes, cat delete, and that exhaust, it still got a minor rasp at 2200 RPM. Wasn't near as noticeable since it was quieter. I will admit the system did sound great, but looking at the custom build of the pipes, it looked very restrictive. Worst comes to worst, if I'm still getting a rasp after adding the high flow cats, I'll look into ditching the LM for a bullet muffler or something else if need be. I think the cats will solve the problem I'm looking for, but still keep the same loud and mean tone. I'm unsure of what my Y pipe is, but I know for a fact it isn't stock.

The only way to get rid of the rasp it to get the POWERFLO. Its the two mufflers that slp sells to put at the end of the exhaust just before the tips.

I have had 5 camaros and 3 different exhausts. Magnaflow suxs if you want power. I got dyno sheets to prove it. I would never go back to magnaflow. The loudmouth is by far the best flowing but if you hate the RASP its not for you.

I just did my cam and heads and it made the car soooo much louder. I bought the powerflo from slp and now its a very deep, no rasp good tone.

If you have loudmouth one or two, headers and no cats you will NOT get rid of the rasp without the powerflo form slp.

**Mike0202** · 02-25-2011, 03:16 PM

Originally Posted by pewterzron

The only way to get rid of the rasp it to get the POWERFLO. Its the two mufflers that slp sells to put at the end of the exhaust just before the tips.

I have had 5 camaros and 3 different exhausts. Magnaflow suxs if you want power. I got dyno sheets to prove it. I would never go back to magnaflow. The loudmouth is by far the best flowing but if you hate the RASP its not for you.

I just did my cam and heads and it made the car soooo much louder. I bought the powerflo from slp and now its a very deep, no rasp good tone.

If you have loudmouth one or two, headers and no cats you will NOT get rid of the rasp without the powerflo form slp.

Could you even drive a heads/cammed loudmouth car around? haha I like how they sound with LT's and simple bolt ons but I cant imagine one with engine work.

**02SS35th** · 02-25-2011, 09:45 PM

Now my only concern is fitting the new high flow cats on with the current ORY. Easily doable? I know I've seen plenty of catted Y's you can buy, but why spend so much when I've already got a 3" one?

I do love the sound of the WOT on the LM1 with headers and no cats. It's nice to know people know you're pissed when you get cut off and you blow by them. I'm really just hoping once I add these cats (if it's even doable with my current ORY) my low 2200 RPM rasp will go away. I've looked for setups the same as mine with and without cats, and of course you can't tell with idle revving at all. If anyone can confirm cats are the solution to this problem, that'd be great. If not, I'll look into a LMII possibly. The Powerflo's seem too quiet for my taste, though that deep tone is what many people like.

**Danger731** · 02-26-2011, 03:02 AM

After this next smog I'm thinking of going LT's. It is gunna be loud!

**importhater81** · 02-26-2011, 03:19 AM

A true dual exhaust set-up gets rid of the rasp.

**Firebirdjones** · 02-26-2011, 07:41 PM

Originally Posted by importhater81

A true dual exhaust set-up gets rid of the rasp.

Just about all the 3 inch single catbacks have some form of rasp, the intensity is just based off how much you choke the motor down with cats, or muffler styles. You are trying to force nearly 400 hp down a single pipe.

If you really like the deep tone without the rasp there is only a couple ways to do it without sacraficing power.

If you want to keep the single systems, you need to increase the pipe diameter. Or go with a real dual exhaust setup of some form. Otherwise you are just bandaiding the issue.

**02SS35th** · 02-28-2011, 12:16 AM

Originally Posted by Mike0202

I will be running Pacesetter Long tubes, Texas speed Y, Magnaflow high flow cats to an Slp Loudmouth in the spring time. Ill let you know how much the cats tame it down.

Someone else said magnaflow but on a stock internal car it really doesnt sound mean at all.

My car sounded very tame with the Magnaflow catback on. Not to mention, the way the pipes were customized into a quad tip CME setup, the pipes were making some wicked 45 degree angles to look good. Just looking at it made me wonder how, if it even did, restrict the flow.

Getting the high flow cats installed in the morning so hopefully I'll be running Hooker Super Comp LT's, Catted ORY, and a non raspy LM1!

**02SS35th** · 02-28-2011, 07:14 AM

Cats are on. Rasp is non existent, much quieter on the interior resonance, but still has the loudmouth growl. Quieter at idle and low throttle, roars at WOT. I'd say these $38 high flow cats were a perfect addition! Loudmouth I sounds amazing with Hooker Longtubes, and a catted ORY. If I can get some sound clips, I'll post. Very satisfied, and it was exactly what I was looking for.

**Mike0202** · 02-28-2011, 09:10 AM

Originally Posted by 02SS35th

Cats are on. Rasp is non existent, much quieter on the interior resonance, but still has the loudmouth growl. Quieter at idle and low throttle, roars at WOT. I'd say these $38 high flow cats were a perfect addition! Loudmouth I sounds amazing with Hooker Longtubes, and a catted ORY. If I can get some sound clips, I'll post. Very satisfied, and it was exactly what I was looking for.

Dammit I have to wait until all this damn snow melts to hook my car up with that set up. Is it still just as loud at wot?

**02SS35th** · 02-28-2011, 03:45 PM

I'd say it's a little quieter, but not by much at all. That loud drone is completely gone and it sounds very refined throughout all RPM ranges. If you still want the loudest of loud, keep the cats off, but if you want to take it down 1 notch or so, have a quieter inside, and want to not deal with that rasp without changing out a Loudmouth I, the cats are a great investment.

I"m just trying to figure out how I passed inspection twice with longtubes, and no cats. Either Texas is relaxed on emissions, or they really like my car.

**35th-ANV-SS** · 02-28-2011, 03:48 PM

I don't have cats on mine and I passed. i just have the rear o2's tuned out so they read a constant voltage showing by the means of the PCM that they are still there, and working properly.

All they do in IN is plug into the PCM...no visual.