1BADFNZ

Here's the situation:

Installed GMMG, Interior noise level higher than expected with MACS and Ypipe w/ cats, but acceptable.

QTP LT's and ORY on the way. I've been advised the the ORY will make interior noise nearly unbearable.

Switching to QTP y pipe w/ Carsound Cats to keep noise level inside bearable.

The LT's I ordered have no AIR provisions.

Will I mess up the cats in the Y pipe by not having AIR?? I live in SC and NO EMISSIONS.

Can I get away with the "race style" LT's and no AIR and not harm my ypipe and cats??

Thanks

dudas35

iTrader: (4)

The air system on a stock system is to help light off the cats when it is cold. I do not believe that any harm will come to the cats if you remove it.

cm02WS6

This is something I struggled with when purchasing my headers. The AIR should help the life of the cats by heating them up quicker. However, I think the difference would be small at best, especially considering the LS1 heats up quickly. I doubt it would make more than a 10% difference in the life of the cats. In the end, I got the AIR provisions just for peace of mind.

Ferocity02

iTrader: (60)

You shouldn't have any problems, but I was wondering why you are getting cats for the interior noise. Something like bullet mufflers may help too, and they cost 1/4 as much as Carsound cats.

1BADFNZ

Well I've got the GMMG installed and the interior noise level while cruising @ 1700-200 rpm is a little louder than I was expecting. I checked around and people here tell me that the ORY with LT's and GMMG will be ear bleading loud on the inside.

This car is my daily driver so I have to live with it and don't have the $$ to keep changing exhaust systems. People here tell me that the cats will help keep the interior noise level down. I'm also gonna put my rear seats back and see if that helps.

Currently the Car has MAC Mids with the MAC ypipe and cats and the noise level is acceptable, but like I said in another post they were saying that the LT's and ORY would be too loud

Where would the bullet mufflers go??? I went with the GMMG and QTP cause I wanted an all stainless exhaust and don't really want to chop up the y pipe or I pipe

Ferocity02

iTrader: (60)

Well...sound level is all opinion. I have MAC's also, with 3" duals dumped before the axle. I think the noise level inside is very acceptable, could even be a little louder... It's all opinion, but it sounds like you don't like noise since you GMMG set-up is significantly quieter then my set-up. If someone is sitting in the passenger seat, I can't hear them talking above 2000 RPM... I don't think bullets will offer the sound deadening you are looking for, but just threw it out there since they flow better and are cheaper than cats. They would go in under the driver and passenger floorboards. And yes, putting in the rear seats will help alot, when I took mine out I noticied a huge increase in interior noise.

1BADFNZ

That might fix my problem then I'll put the seats back in this weekend and see how it does. Now back to the ORY v/s Cats how much of a difference does that make??

Maybe I'm just getting older but I like it to be loud when I step on the gas but not for regular driving, Of course on my old LT1 Z i had the flowmaster 80 series muffler installed and it was loud as hell inside !!!! Guess i'm just a little gun shy LOL