To cat or not to cat....That is the ? - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

Deep Six · 11-12-2013, 09:32 AM

Going to add a front pipe and possibly an overpipe to the Ultimate Racing 3" catback. Header will have to wait until I decide what FI path to follow. The reason I am posting here is due to decibel restrictions at many tracks. I plan to include AMP and Barber to the mix and don't want to travel all the way there for a black flag. The question is catted? resonated? both? I plan to have the car tuned (93 & E85) this month once the rest of the exhaust is installed as well.

Clip from the UR 3"

[ame="http://www.youtube.com/watch?v=Eo5Kfb5aYGc"]Ultimate Racing 3" Catback - YouTube[/ame]

7thgear · 11-12-2013, 09:54 AM

are you using the term cat/catted as a cat-back or are you refering to the actual catalytic converter?

Deep Six · 11-12-2013, 06:42 PM

As in catalytic converter specifically to reduce the sound volume. I don't have emission checks where I live so my choice is louder and slightly more powerful or quieter to pass the sound police at certain tracks.

autobrz · 11-12-2013, 06:54 PM

can you just put 2 resonators in there to quiet things down? You can even put in 3 if you don't need cats. They don't affect flow, I think. I heard dynomax mufflers are really quiet and free flowing, too

Superhatch · 11-12-2013, 07:02 PM

There was an article a while back where some magazine took a Civic Si and replaced the factory exhaust with a cat-back version, then changed out the cats from OEM to test pipe. The max difference between them was about 1.5hp.

Maybe once you are FI you might see 5hp, maybe but I wouldn't consider it a part that needed to be removed as a huge block to power. Especially since a high-flow version will get you nearly what you would get with a test pipe.

sw20kosh · 11-13-2013, 12:15 AM

Quote:

Originally Posted by Superhatch

There was an article a while back where some magazine took a Civic Si and replaced the factory exhaust with a cat-back version, then changed out the cats from OEM to test pipe. The max difference between them was about 1.5hp.

Maybe once you are FI you might see 5hp, maybe but I wouldn't consider it a part that needed to be removed as a huge block to power. Especially since a high-flow version will get you nearly what you would get with a test pipe.

He is concerned with sound.

IMO get cats because they have the added benefit of cutting down on smell.

Superhatch · 11-13-2013, 10:03 AM

Quote:

Originally Posted by sw20kosh

He is concerned with sound.

"louder and slightly more powerful"

I wanted to try and quantify "slightly more powerful" for him.

11-12-2013, 09:32 AM	#1
Deep Six Senior Member Join Date: May 2013 Drives: 2013 FRS / 2013 427 Vert Location: Orlando Posts: 611 Thanks: 212 Thanked 328 Times in 197 Posts Mentioned: 5 Post(s) Tagged: 0 Thread(s)	To cat or not to cat....That is the ? Going to add a front pipe and possibly an overpipe to the Ultimate Racing 3" catback. Header will have to wait until I decide what FI path to follow. The reason I am posting here is due to decibel restrictions at many tracks. I plan to include AMP and Barber to the mix and don't want to travel all the way there for a black flag. The question is catted? resonated? both? I plan to have the car tuned (93 & E85) this month once the rest of the exhaust is installed as well. Clip from the UR 3" [ame="http://www.youtube.com/watch?v=Eo5Kfb5aYGc"]Ultimate Racing 3" Catback - YouTube[/ame] __________________ [SIGPIC][/SIGPIC] 2013 FR-S Asphalt BC Coils/Rev Works UEL header/HKS Front Pipe/Racing Brake BBK/Shorai LW Battery/ACT 6 Puck Clutch/FBM Radiator & Oil Pan/JR Oil Cooler/Jackson Racing High Boost C30/Rev Works Built Motor 2016 Audi TTS APR Tuned

11-12-2013, 09:54 AM	#2
7thgear i'm sorry, what? Join Date: Jan 2012 Drives: Canada Location: I rock a beat harder than you can beat it with rocks Posts: 4,399 Thanks: 357 Thanked 2,508 Times in 1,268 Posts Mentioned: 40 Post(s) Tagged: 3 Thread(s)	are you using the term cat/catted as a cat-back or are you refering to the actual catalytic converter? __________________ don't you think if I was wrong, I'd know it?

11-12-2013, 06:42 PM	#3
Deep Six Senior Member Join Date: May 2013 Drives: 2013 FRS / 2013 427 Vert Location: Orlando Posts: 611 Thanks: 212 Thanked 328 Times in 197 Posts Mentioned: 5 Post(s) Tagged: 0 Thread(s)	As in catalytic converter specifically to reduce the sound volume. I don't have emission checks where I live so my choice is louder and slightly more powerful or quieter to pass the sound police at certain tracks. __________________ [SIGPIC][/SIGPIC] 2013 FR-S Asphalt BC Coils/Rev Works UEL header/HKS Front Pipe/Racing Brake BBK/Shorai LW Battery/ACT 6 Puck Clutch/FBM Radiator & Oil Pan/JR Oil Cooler/Jackson Racing High Boost C30/Rev Works Built Motor 2016 Audi TTS APR Tuned

11-12-2013, 07:02 PM	#5
Superhatch AIM4APX Join Date: Jun 2012 Drives: 2013 WRB BRZ Limited Location: Milwaukee Posts: 1,206 Thanks: 642 Thanked 749 Times in 324 Posts Mentioned: 8 Post(s) Tagged: 0 Thread(s)	There was an article a while back where some magazine took a Civic Si and replaced the factory exhaust with a cat-back version, then changed out the cats from OEM to test pipe. The max difference between them was about 1.5hp. Maybe once you are FI you might see 5hp, maybe but I wouldn't consider it a part that needed to be removed as a huge block to power. Especially since a high-flow version will get you nearly what you would get with a test pipe. __________________ "It's very difficult to present technology as an overtly positive sales device to people who want an emotional car" -Chris Harris

11-12-2013, 06:54 PM	#4
autobrz Senior Member Join Date: May 2013 Drives: Mazda 3 Location: round rock, tx Posts: 413 Thanks: 487 Thanked 108 Times in 74 Posts Mentioned: 4 Post(s) Tagged: 0 Thread(s)	can you just put 2 resonators in there to quiet things down? You can even put in 3 if you don't need cats. They don't affect flow, I think. I heard dynomax mufflers are really quiet and free flowing, too

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