pros and cons on removing cats

06 T-RED S/C GT

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yea they're not the loudest. I can of like them though.

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If I would've stayed catless/off-road? My next choice would also be Borla Touring. I also asked earlier if the type of wool you use in the trunk, under the spare tire is Owens Corning Fiberglass for insulating walls???
 

Johnstone

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yes.. underspare and over.. basically where the wheel well
If I would've stayed catless/off-road? My next choice would also be Borla Touring. I also asked earlier if the type of wool you use in the trunk, under the spare tire is Owens Corning Fiberglass for insulating walls???

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06 T-RED S/C GT

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yes.. underspare and over.. basically where the wheel well

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Yes, I understand where you placed it under the spare in the trunk. However, my question was is the material made by Owens/Corning Fiberglass that is used for insulating home interior walls?
 

Johnstone

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yes the one to insulate homes.
Yes, I understand where you placed it under the spare in the trunk. However, my question was is the material made by Owens/Corning Fiberglass that is used for insulating home interior walls?

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Are you running an off-road H or off-road X pipe? Also, do high-flow cats really make a noticeable difference with rasp, exhaust loudness and reducing exhaust fume smell?

I was running longtubes offroad H and corsa sports and it was stupid loud. Way too much noise for 300hp, I felt like a honda civic driver. Very raspy and metallic sounding.

The cats take the edge of the volume, give it more of a deep tone and fixed most rasp. Now it only smells on cold start which is normal.

Simple tiny round magnaflow high flow cats.
Also had a custom X made which smoothes everything out even more
 

06 T-RED S/C GT

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IIRC Corsa's are known for producing a raspier exhaust sound, at least the Corsa Extremes are anyhow. However the Corsa Sports, I'm not really sure about. Usually, inline resonators are recommended for reducing interior resonance drone and trumpeting while cats are good for fixing rasp and providing more of a deep tone just as you brought up. I recently made the switch from the Mac ProChamber paired with the OEM cats and Borla S type/Borla ATAK axle backs to the Pypes after cat X pipe, as the ProChamber paired with the OEM cats made the interior resonance drone from both the Borla S type and Borla ATAK mufflers so unbearable that I finally made the decision to pull the plug on the ProChamber in favor of the Pypes after cat X pipe. Although the resonance drone is still there, at least now I can live with it, as I only notice drone when the engine is under a load and also when under 2000 RPM. Other than that, it doesn't really bother me any longer thanks to the after cat X pipe which has made a significant improvement :waytogo:
 
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The corsa's are raspy because they dont have any packing material, just reflecting baffles that cancel out noise and drone. I added some small resonators to make them less tinny with the longtubes.
 

06 T-RED S/C GT

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Between the small resonators, you added along with you're Magnaflow high-flow cats and custom X pipe should most definitely fix all your raspy and tinny issues from the longtubes and Corsa sports. I also totally agree with the Corsas having more of a raspier sound because they don't have any packing material just as you mentioned which is just another reason that Corsa intended for their muffler systems to be designed for the stock exhaust.
 

Eagleee

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I run catless and my headaches like shite if I drive windows down for few hours. For me, I hate the smell but I LOVE the sound!
 

Johnstone

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finally got it back.. I ended up putting cats back. sounds good for now.

also got a dyno tune.. pushed 435 Hp on the dyno. not to shabby. 11.5lbs of boost

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06 T-RED S/C GT

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finally got it back.. I ended up putting cats back. sounds good for now.

also got a dyno tune.. pushed 435 Hp on the dyno. not to shabby. 11.5lbs of boost

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I'm glad it sounds good with the cats back on. Also, 435 HP on the dyno at 11.5 lbs of boost isn't too shabby at all, especially with the stock cats on. Congrats :waytogo:
 

07 Boss

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finally got it back.. I ended up putting cats back. sounds good for now.

also got a dyno tune.. pushed 435 Hp on the dyno. not to shabby. 11.5lbs of boost

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Actually seems kinda low to me. I made 50 more rwhp with 11.3 psi. I do have some mild nsr cams and headers, oh and an electric H2O pump also, but do you think that's worth 50 hp?
 

Johnstone

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Actually seems kinda low to me. I made 50 more rwhp with 11.3 psi. I do have some mild nsr cams and headers, oh and an electric H2O pump also, but do you think that's worth 50 hp?
probably.. I have a gt500 gas pump but not cams. just a blower. edelbrock

car runs well.. only problem I'm having now is my exhaust comes apart. my clamps cant hold the cat backs. the pro shop did an amazing job on everything but that he sort of neglected.

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06 T-RED S/C GT

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Actually seems kinda low to me. I made 50 more rwhp with 11.3 psi. I do have some mild nsr cams and headers, oh and an electric H2O pump also, but do you think that's worth 50 hp?
The electric water pump combined with the nsr cams and headers? Yea, I would say they're worth 50HP

probably.. I have a gt500 gas pump but not cams. just a blower. edelbrock

car runs well.. only problem I'm having now is my exhaust comes apart. my clamps cant hold the cat backs. the pro shop did an amazing job on everything but that he sort of neglected.

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A GT500 fuel pump isn't going to give you more HP, but deliver more fuel over the stock pump. IMO I think 435 HP with just the Edelbrock blower alone at 11.5 psi of boost is pretty good. As for your exhaust clamps, which type are they? If their U clamps? I'd recommend switching to band clamps which have much better quality and don't damage your pipes. If you suspect the pro shop for neglecting to install your clamps correctly? then it's more than obvious your going to take your car back to the shop and have them make things right lol.
 
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boostedtrauma

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I'm also supercharged. I've been catless with JBA long tubes, offroad H, and Borla Touring for years. I'm not in an emissions state, so it isn't an issue for me, but it would be if I was and was ever stopped. It has a smell, nothing major, but its noticeable. It is MUCH louder without cats than it was with them. My 07 without cats and Borla Touring sounds very, very similar to my 06 with cats and Borla Stingers.

Removing them will prevent future failure. It's a good idea IMO if you're running conservative (rich) while boosted or using an N2MB that'll be throwing a lot of unspent fuel in the cats.
 

07Bossman

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In this modern era, and referencing just the S197 3V here, unless you are running supercharged, removing cats is a questionable-at-best move.
With all the newer engines out there, the N/A capabilities of the 3V are a joke. It's all bark no bite. So why go through all the headache of stinky exhausts, rumbly cams, and being tied to a tuner for a car that barely responds to bolt ons?
 

07 Boss

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In this modern era, and referencing just the S197 3V here, unless you are running supercharged, removing cats is a questionable-at-best move.
With all the newer engines out there, the N/A capabilities of the 3V are a joke. It's all bark no bite. So why go through all the headache of stinky exhausts, rumbly cams, and being tied to a tuner for a car that barely responds to bolt ons?

Some of us might want a loud raw obnoxious exhaust. Stinky to you, but some of us actually like the smell of petrol and burning rubber. The rumbly cams I agree with, I would rather have a smooth idle. Having a tuner is debatable. I've made a lot of driving improvements to the car while N/A, from throttle response to tranny shift points. And your user name is way to close to mine
 

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