Here's my deal, i love loud, the louder the muscle car the happier i am. So when i bought my LS1 i got the SLP loudmouth catback b/c i fiugred it was the loudest i can get w/out payin through the nose. Now my next plan was to save up 1200 bux and buy QTP headers and y-pipe w/ high flow carsound cats. All i've been hearing is that you get a horrible rasp w/ this setup ...i deffinatly need cats for emmission purposes here in CT. So if i dont spend the money on the LT's and ypipe, how much horse am i sacrificing by keeping the stock manifold and y-pipe??? Are there simple bolt ons i can do to make up the power loss, i love the sound i get w/ the stock manifold/y-pipe but it just seems incomplete w/out them. What do you guys think?? Is there maybe a better cat back to make it sound less raspy w/ headers/catted ypipe?? Thanks

 

Wow your posting all over lol! You are in luck. I am in a similiar boat. Long tubes and off road y pipe is worth between 15-30 RWHP. Usually right around 25though. There is always other mods you can do for more speed. Eventually though it will hold you back when you engine needs to "exhale" better - like heads, or an agressive cam.

Anyways I have a loudmouth also and have heard all the talk of rasp and being too loud. Well I am undertaking the project this Friday. I am going with Flowtech Long Tube Headers, no cats y pipe and Loudmouth. I am going to find out first hand what its like. I'm not even sure what rasp sounds like at this point. I do know my friend has a Vette with headers, no cats, and no mufflers and yeah its pretty loud, but tolerable in my book. I like it loud. I just don't like the DRONING sound at highway speeds. I usually fix that by driving faster or slower though. <66 or >75. Changing gears will move that to a different range though.

Anyways I will let you - and everyone else know how it sounds when all is complete.

 

Yea, tis the season...my life revolves around my car and my job consists of sitting in front of a computer all day so i have time to sit and think about m y car and post tons of threads to get my thoughts out. Well, i'm not lookin to do an off road, i have to have cats for emissions...qtp makes the carsound cats w/ theirs so i was lookin into that, and like urself, i dont care how loud it is, just as long as it isnt this loud "rasp" that sounds horrible that everyone is ssaying. Thanks for the response.

 

Hey I am with you there too man. I sit in front of a computer all day doing tech support. I post and respond to forums all darn day - contemplate mods etc.....My thoughts are divided with my kids and gifrlfriend too though lol. Are they tough about emissions in your state? They are real relaxed about it in michigan - at least for now. But my setup would not pass emissions if I were tested.

 

If you go with QTPs Catted Y pipe you won't have any rasp even with the loudmouth. My Corsa LTs ORY was very raspy also but after adding the cats it disappeared. That setup will be loud even with the cats but it will be rasp free.

 

Really, ur the only one who has said that so far...can anyone else back you on that?? Not that i dont believe you but w/ these forums i go by majority and so far 30 or 40 people have said rasp is a deffinate thing. So anyone else think cats will eliminate or minimize rasp??? Thanks though dude, now ur gettin my hopes back up again

 

Rasp is caused by using an ORY pipe on the LS1. When you add cats back to the setup your rasp will be gone. Do you have any rasp with your stock manifolds and cats? I'm guessing not. Adding cats to LTs @ Loudmouth will eliminate the rasp but it will still be very loud due to the added flow volume from the headers. From my personal experience adding cats to my LTs ORY Corsa setup the rasp was gone and it really cleaned the sound up also. Before the cats it was a raw frantic type exhaust note. After the cats it became a deep rumble that sounds alot better IMO.

 

Cats ususally do a good job of cutting out the rasp.

 

Yea i really dont have any rasp right now w/ the stock manifolds/ypipe. Well that sounds good from what your saying, i guess i do have to save up the $$$ after all, any other opinions are still welcome though. Thanks for the info all.

 

If I end up not like the sound of mine, I will simply have the exhaust modified. Put in a real muffler instead of the resonator like the other guys do. I listened to a website that had long tubes and headers with no cats and it didn't sound that much different than what i have now - of course it IS hard to get an accurate measurement of exhaust by a sound clip over computer speakers.....

 

I put the QTP LT's Catted y and GMMG on mine, Nice and loud, no rasp, interior noise levels at cruise are quiet

 

Go true duals, and forget your rasp problems. Best mod I did on my car after I did my cam swap. I almost hate the raspy sound of a uncatted + catback F-Body now. To me, it actually sounds like ***.

But putting cats back on should help with the noise though...

 

I agree with the LT + Cats + LM = no rasp.
When I just had the LM on by itself, I had more rasp with just the stock exhaust.
I think it sounds great, but it does get loud and it drones a little. I am used to it now, because it drowns out the Bumble Bee sounds of the Rice cars in my area.

 

True

 

I live in CT, and I am having a set of QTP longtubes and cattedY pipe installed this weekend. I also have a loudmouth on my car. Send me an e-mail, I'll give you a call after I get them on. I go to alt of cruie shows, you could probably run into me at the Vernon cruise on Frday nights in 2 weeks, I should have them on by then ( going on on the 17th )