Username or Email Address
Do you already have an account?
Forgot your password?
  • Log in or Sign up

    VWVortex


    Page 1 of 2 12 LastLast
    Results 1 to 35 of 46

    Thread: Cat-less vs Catted

    1. Member ShutItDown's Avatar
      Join Date
      Jun 14th, 2007
      Location
      Kansas City, Missouri
      Posts
      1,840
      Vehicles
      2006 Subaru Baja Turbo
      05-03-2009 09:42 PM #1
      Some interesting information on test pipe vs cat. Would be useful when looking for a ATP cat-less DP vs catted DP's.

      http://evoempire.org/Test-Pipe...rplus

      Sold: 1993 240sx SR20DET
      Sold: 2004 JCW Mini Cooper S
      Sold: 2007 Volkswagen GTI APR S2+
      Now: 2006 Subaru Baja Turbo
      WTB: MKII GTI

    2. Member Josein06GLI's Avatar
      Join Date
      Jun 28th, 2008
      Location
      San Diego, Ca
      Posts
      3,875
      Vehicles
      2012 Audi , 2006 VW Jetta GLI, 1989 MK2 GTI VR6
      05-04-2009 12:37 AM #2
      my boy has a apr downpipe and i have the atp catless. neither one of us have software and we both have dsg and i pull on him a little bit, its a straight pipe, also maybe its just me, i think the car warms up quicker in the mornings.
      2006 BMP VW JETTA GLI DSG some coils, some bolt ons and some wheels.
      1989 VW GTI 2.8l VR6 some coils, some bolt ons, and some wheels.
      2012 Audi all stock, its hers. she dont want me messing with it...yet.

    3. Member wazzap1101's Avatar
      Join Date
      May 1st, 2009
      Location
      Long Island
      Posts
      870
      Vehicles
      APR STG 3 2007 VW MKV GTi DSG
      05-04-2009 03:32 PM #3
      the bottom line is the catted is more restrictive than non-catted.

      WIth a cat, you're sacrificing performance to pass inspection and be more environmentally friendly. It all depends if your willing to make the tradeoff, and personal preference.

      BTW, nice info ShutItDown


    4. Member ShutItDown's Avatar
      Join Date
      Jun 14th, 2007
      Location
      Kansas City, Missouri
      Posts
      1,840
      Vehicles
      2006 Subaru Baja Turbo
      05-04-2009 09:42 PM #4
      Quote, originally posted by wazzap1101 »
      the bottom line is the catted is more restrictive than non-catted.

      WIth a cat, you're sacrificing performance to pass inspection and be more environmentally friendly. It all depends if your willing to make the tradeoff, and personal preference.

      BTW, nice info ShutItDown

      No problem. Everyone know a cat is more restrictive but all these high flow 100 cell cats that claim to be the same performance as test pipe set up and this is some good information against it.

      Sold: 1993 240sx SR20DET
      Sold: 2004 JCW Mini Cooper S
      Sold: 2007 Volkswagen GTI APR S2+
      Now: 2006 Subaru Baja Turbo
      WTB: MKII GTI

    5. 11-12-2009 07:42 PM #5
      i run an ebay DP with a magnaflow 200cell cat..i did it mainly to pass emissions but i did notice the power and the sounds mated to the stock exhaust is much nicer than i expected

    6. Banner Advertiser Chris@Revo USA's Avatar
      Join Date
      May 17th, 2007
      Location
      Summit Point, WV
      Posts
      9,880
      Vehicles
      X,80,X,X,98,00,X,06,12
      11-13-2009 09:21 AM #6
      I run a cat with my GT3582R

    7. Member SmithersSP's Avatar
      Join Date
      May 24th, 2006
      Location
      Charlotte, NC
      Posts
      4,902
      Vehicles
      REVO STGIII S3 K04 06' PG GLI, C2 97' GLX
      11-13-2009 10:21 AM #7
      Quote, originally posted by MK3Serge »
      i run an ebay DP with a magnaflow 200cell cat..i did it mainly to pass emissions but i did notice the power and the sounds mated to the stock exhaust is much nicer than i expected


      I have the same setup. It wasn't that I needed it to pass inspection, or that I'm a treehugger; more so that I got sick of the ass end of my GLI smelling of raw unspent fuel... While I doubt my car would pass a comprehensive emissions test the cat takes car of the fuel smell...
      Chapter 11 Dubs
      Revo STGIII Kegerator
      Quote Originally Posted by jhines_06gli View Post
      I fix Pete's car to keep cold, cheap beer flowing for the club at shows.

    8. Member bostonaudi1's Avatar
      Join Date
      May 13th, 2006
      Location
      Charleston, SC
      Posts
      1,040
      Vehicles
      2008 VW GTI, 1995 BWM M3
      11-13-2009 05:56 PM #8
      Quote, originally posted by wazzap1101 »
      the bottom line is the catted is more restrictive than non-catted.

      WIth a cat, you're sacrificing performance to pass inspection and be more environmentally friendly. It all depends if your willing to make the tradeoff, and personal preference.

      BTW, nice info ShutItDown

      BS

      Sure, but somehow Porsche, Corvette and many others can extract 400+ hp easily with cats in place. You're "sacrificing" almost NO performance with a high flow cat, and performing the completely selfish act of trashing the air for EVERYONE else when removing it.

      I ME MINE





      Modified by bostonaudi1 at 5:58 PM 11-13-2009

      2008 GTI Option 0 - Daily driver and track car (#62)
      PCA HPDE Instructor
      http://www.jkautomotive.net/

    9. 11-16-2009 11:25 AM #9
      Quote, originally posted by SmithersSP »

      It wasn't that I needed it to pass inspection, or that I'm a treehugger; more so that I got sick of the ass end of my GLI smelling of raw unspent fuel...

      same here. that ish stunk


    10. Member Josein06GLI's Avatar
      Join Date
      Jun 28th, 2008
      Location
      San Diego, Ca
      Posts
      3,875
      Vehicles
      2012 Audi , 2006 VW Jetta GLI, 1989 MK2 GTI VR6
      11-16-2009 05:23 PM #10
      i have an atp catless DP nd i love it cuz it was 300 bucks and mainly cheaper cuz it doesnt have a cat, a catted DP runs upwards of like 500-900 depending on what brand, catless for me, who cares what it smells like, get chipped and u wont even need a spacer for u catless dp guys
      2006 BMP VW JETTA GLI DSG some coils, some bolt ons and some wheels.
      1989 VW GTI 2.8l VR6 some coils, some bolt ons, and some wheels.
      2012 Audi all stock, its hers. she dont want me messing with it...yet.

    11. Member SmithersSP's Avatar
      Join Date
      May 24th, 2006
      Location
      Charlotte, NC
      Posts
      4,902
      Vehicles
      REVO STGIII S3 K04 06' PG GLI, C2 97' GLX
      11-16-2009 06:08 PM #11
      I couldn't help but notice you live in SD. If you don't mind me asking; how do you pass a smog check?
      Thanks!
      Chapter 11 Dubs
      Revo STGIII Kegerator
      Quote Originally Posted by jhines_06gli View Post
      I fix Pete's car to keep cold, cheap beer flowing for the club at shows.

    12. Member ShutItDown's Avatar
      Join Date
      Jun 14th, 2007
      Location
      Kansas City, Missouri
      Posts
      1,840
      Vehicles
      2006 Subaru Baja Turbo
      11-16-2009 08:53 PM #12
      How often do you have to check your car? I would assume he would just put the other one on before he has to check it.
      Sold: 1993 240sx SR20DET
      Sold: 2004 JCW Mini Cooper S
      Sold: 2007 Volkswagen GTI APR S2+
      Now: 2006 Subaru Baja Turbo
      WTB: MKII GTI

    13. Member Josein06GLI's Avatar
      Join Date
      Jun 28th, 2008
      Location
      San Diego, Ca
      Posts
      3,875
      Vehicles
      2012 Audi , 2006 VW Jetta GLI, 1989 MK2 GTI VR6
      11-17-2009 02:05 PM #13
      well in cali the car isnt due for smog until its 6 years old, my GLI is an 06 so its due for its first smog in 2012, at which point i WILL NOT own the car anymore and if i do theres places to get it done "under the rug" using a dummy car
      2006 BMP VW JETTA GLI DSG some coils, some bolt ons and some wheels.
      1989 VW GTI 2.8l VR6 some coils, some bolt ons, and some wheels.
      2012 Audi all stock, its hers. she dont want me messing with it...yet.

    14. Banner Advertiser Chris@Revo USA's Avatar
      Join Date
      May 17th, 2007
      Location
      Summit Point, WV
      Posts
      9,880
      Vehicles
      X,80,X,X,98,00,X,06,12
      11-17-2009 02:24 PM #14
      Quote, originally posted by Josein06GLI »
      well in cali the car isnt due for smog until its 6 years old, my GLI is an 06 so its due for its first smog in 2012, at which point i WILL NOT own the car anymore and if i do theres places to get it done "under the rug" using a dummy car

      Wow 6 years... and people complain about smog in california? Even here in Georgia they do it after 2 years.. NJ was 4 years on new car and some states are even 1 year. I think NC smogs cars before they are delivered to the dealers..


    15. 11-17-2009 03:21 PM #15
      Quote, originally posted by bostonaudi1 »

      BS

      Sure, but somehow Porsche, Corvette and many others can extract 400+ hp easily with cats in place. You're "sacrificing" almost NO performance with a high flow cat, and performing the completely selfish act of trashing the air for EVERYONE else when removing it.

      I ME MINE

      Modified by bostonaudi1 at 5:58 PM 11-13-2009

      You said: "Porsche, Corvette and many others can extract 400+ hp easily with cats in place". I say Yea, but do you realize what kinda power those cars would have if they had the cats removed? It would blow your mind, You'd be shocked @ how much more power they'd have. That is why I choose to run the ATP.

      Sold the VAG COM

    16. Senior Member MFZERO's Avatar
      Join Date
      Mar 13th, 2002
      Location
      Haverhill, Ma.
      Posts
      33,210
      Vehicles
      2011 Kink Gap Xl, 2000 Haro Blammo,'08 Gti
      11-17-2009 03:25 PM #16
      it's an age old battle.
      p.s. the first link doesn't work

    17. Member Krieger's Avatar
      Join Date
      May 5th, 2009
      Location
      Orlando, FL
      Posts
      4,182
      Vehicles
      Turbocharged 2004 Civic SI with K20/K24 engine swap, 2006 Audi A3
      11-17-2009 03:29 PM #17
      that honeycomb in a cat will not rob u of much power.

      even in turbo charged cars ur really only gonna gain a VERY minimal amount of ponies over a catted pipe... and the difference is even less on a N/A engine as they need back pressure to keep the exhaust flowing right and maintain the exhaust pulse and velocity as it travels down the system.


      i run catless, but as soon as i get around to it, imma hack up my pipe and weld in a nice metallic cat, i will then dyno my car again and prove to u that just like all the other cars ive ever worked on, this one wont lose much, if any at all, horsepower or torque just because a thin catalytic material happens to be in the system...

      2006 Audi A3 | 2.0T | 6MT | APR Stage 2+ | Fully loaded ECU | FK grill | EJ CAI | BSH TBP |EJ DV Reloc. | Eurojet TBE | EuroJet Catch Tank | Cross drilled and Slotted Rotors | EBC "Redstuff" Kevlar | Raceland Coilovers | Forge Side to Side Short Shifter | Forge Front to Back Short Shifter | Devil's Own DVC-30 Methanol injection | BSH RSB | BSH Motor mount Kit | 42 DD Shifter Bushings | HPFP Stage 1 upgrade |

    18. 11-17-2009 04:29 PM #18
      In high school (1991) my buddy had (& still has) a 1988 Monte Carlo SS. He put a 400whp - 383 Stroker in it w/Dart heads & a 750cfm carb. Art Carr Transmission with 4.10 grears in the rear

      The car had a custom dual exhaust installed consisting of two, 2.5" pipes leading into "2 chamber" (loud as hell) Flowmaster mufflers & that was it. It was a friggin beast.

      One day we got pulled over & the cop actually went down on his hands & knees & looked at his exhaust. Thus busting him for no cats. So he went back to the exhaust shop & had them weld in to high flow race cats & afterwards I drove the car. The diffeerence was night & day.

      Before the cats were put on, the car hauled ass during the mid range & top end it was incredible. After the cats were installed it lost ALL of that. Now down low it was a torque monster, but the midrange & top end were non exsistant compared to before.


      Modified by rippie74 at 4:31 PM 11-17-2009

      Sold the VAG COM

    19. Member SmithersSP's Avatar
      Join Date
      May 24th, 2006
      Location
      Charlotte, NC
      Posts
      4,902
      Vehicles
      REVO STGIII S3 K04 06' PG GLI, C2 97' GLX
      11-17-2009 05:02 PM #19
      I'm neutral in this debate so I'm just asking for curiosity sakes; what type of cats were they? Were they standard oem-ish cats or low cell count metallic spun cats?
      Thanks!
      Chapter 11 Dubs
      Revo STGIII Kegerator
      Quote Originally Posted by jhines_06gli View Post
      I fix Pete's car to keep cold, cheap beer flowing for the club at shows.

    20. Member Josein06GLI's Avatar
      Join Date
      Jun 28th, 2008
      Location
      San Diego, Ca
      Posts
      3,875
      Vehicles
      2012 Audi , 2006 VW Jetta GLI, 1989 MK2 GTI VR6
      11-17-2009 11:33 PM #20

      i run catless, but as soon as i get around to it, imma hack up my pipe and weld in a nice metallic cat, i will then dyno my car again and prove to u that just like all the other cars ive ever worked on, this one wont lose much, if any at all, horsepower or torque just because a thin catalytic material happens to be in the system...

      i know u said u were running catless dp, why would u want the risk possibility of losing any if any horsepower or torque ????

      2006 BMP VW JETTA GLI DSG some coils, some bolt ons and some wheels.
      1989 VW GTI 2.8l VR6 some coils, some bolt ons, and some wheels.
      2012 Audi all stock, its hers. she dont want me messing with it...yet.

    21. Member Krieger's Avatar
      Join Date
      May 5th, 2009
      Location
      Orlando, FL
      Posts
      4,182
      Vehicles
      Turbocharged 2004 Civic SI with K20/K24 engine swap, 2006 Audi A3
      11-18-2009 10:17 AM #21
      because if this car is like any other turbo charged car ive ever played with or worked on, the losses will be negligible.

      and if u can feel the loss of like 4 or 5 HP, ur a freak. lmao

      this car runs SUPER rich, so if i catch a wiff of my car's a$$ fumes, it brings a tear to my eye cuz it actually stings when u breath and ****. lol

      2006 Audi A3 | 2.0T | 6MT | APR Stage 2+ | Fully loaded ECU | FK grill | EJ CAI | BSH TBP |EJ DV Reloc. | Eurojet TBE | EuroJet Catch Tank | Cross drilled and Slotted Rotors | EBC "Redstuff" Kevlar | Raceland Coilovers | Forge Side to Side Short Shifter | Forge Front to Back Short Shifter | Devil's Own DVC-30 Methanol injection | BSH RSB | BSH Motor mount Kit | 42 DD Shifter Bushings | HPFP Stage 1 upgrade |

    22. 11-18-2009 11:16 AM #22
      You guys with the ebay DP's and cats. What did you do, buy the ebay DP, then have an exhaust guy weld in the cat? Is the cat in the DP or somewhere downstream in your exhaust?


      Could I use one of, or both of the stock cats with the ebay DP and expect good results, or do I need to get a better flowing cat?

      Thanks

      06' MKV GTI 6MT - APR Stage 1 - Upgraded OEM DV

      Dub on......

    23. Member Krieger's Avatar
      Join Date
      May 5th, 2009
      Location
      Orlando, FL
      Posts
      4,182
      Vehicles
      Turbocharged 2004 Civic SI with K20/K24 engine swap, 2006 Audi A3
      11-18-2009 11:22 AM #23
      stock cats are small, thick, and super restrictive.

      i have an ebay pipe cuz it works, but im gonna get a 200 cell metallic cat. might be from magnaflow, but i like random technology too.

      2006 Audi A3 | 2.0T | 6MT | APR Stage 2+ | Fully loaded ECU | FK grill | EJ CAI | BSH TBP |EJ DV Reloc. | Eurojet TBE | EuroJet Catch Tank | Cross drilled and Slotted Rotors | EBC "Redstuff" Kevlar | Raceland Coilovers | Forge Side to Side Short Shifter | Forge Front to Back Short Shifter | Devil's Own DVC-30 Methanol injection | BSH RSB | BSH Motor mount Kit | 42 DD Shifter Bushings | HPFP Stage 1 upgrade |

    24. Member SmithersSP's Avatar
      Join Date
      May 24th, 2006
      Location
      Charlotte, NC
      Posts
      4,902
      Vehicles
      REVO STGIII S3 K04 06' PG GLI, C2 97' GLX
      11-18-2009 11:26 AM #24
      I bought my catless DP and magnaflow 200 cell cat off ebay. I have a shop weld in the cat. To be honest I didn't notice any difference in the power of the car. I didn't do a pre/post dyno though so who knows for sure...
      Chapter 11 Dubs
      Revo STGIII Kegerator
      Quote Originally Posted by jhines_06gli View Post
      I fix Pete's car to keep cold, cheap beer flowing for the club at shows.

    25. Member Krieger's Avatar
      Join Date
      May 5th, 2009
      Location
      Orlando, FL
      Posts
      4,182
      Vehicles
      Turbocharged 2004 Civic SI with K20/K24 engine swap, 2006 Audi A3
      11-18-2009 11:42 AM #25
      yeah, you wont. your turbo is still gonna be spooling like a beast simply because you got rid of that first cat that was like a brick wall, plus gave it PLENTY of room to flow afterwards. it's not like the honeycomb of a cat is such a huge restriction... ****, most flow more than alot of mufflers.... so if u dont notice a drop in power from a muffler, why would u from a cat?

      100 cell metallic

      200 cell

      neither will block much flow at all... they are far back enough in the exhaust that your turbo will see almost no build up in back pressure... Now, if u went with a much bigger turbo that could move alot more exhaust, faster, u might lose more, but with a K03 or K04, ur not gonna choke up the system.

      2006 Audi A3 | 2.0T | 6MT | APR Stage 2+ | Fully loaded ECU | FK grill | EJ CAI | BSH TBP |EJ DV Reloc. | Eurojet TBE | EuroJet Catch Tank | Cross drilled and Slotted Rotors | EBC "Redstuff" Kevlar | Raceland Coilovers | Forge Side to Side Short Shifter | Forge Front to Back Short Shifter | Devil's Own DVC-30 Methanol injection | BSH RSB | BSH Motor mount Kit | 42 DD Shifter Bushings | HPFP Stage 1 upgrade |

    26. Member Josein06GLI's Avatar
      Join Date
      Jun 28th, 2008
      Location
      San Diego, Ca
      Posts
      3,875
      Vehicles
      2012 Audi , 2006 VW Jetta GLI, 1989 MK2 GTI VR6
      11-19-2009 01:57 AM #26
      well which brings me to the next topic of catted and non catted dp's. first and formost especially with the economy as fuc*ed as it , non catted dp's are wayyyyy cheaper and a quick way to get to stage 2 power when chipped. when i did mine i didnt have 1000 for an APR 200 cell catted dp so i went with an atp catless, i love it, no issues and its been on the car for a while i got 71k miles on my 06 and put it on around 20k or so, no rust either, plus it was used and i go for like 300 shipped. 700 bucks saved, wheres the problem? lol
      2006 BMP VW JETTA GLI DSG some coils, some bolt ons and some wheels.
      1989 VW GTI 2.8l VR6 some coils, some bolt ons, and some wheels.
      2012 Audi all stock, its hers. she dont want me messing with it...yet.

    27. Member Krieger's Avatar
      Join Date
      May 5th, 2009
      Location
      Orlando, FL
      Posts
      4,182
      Vehicles
      Turbocharged 2004 Civic SI with K20/K24 engine swap, 2006 Audi A3
      11-19-2009 02:12 AM #27
      u paid 300 for a used catless ATP pipe??? dude, u overpaid... i got mine for 160 shipped to my door, new, and its an exact replica of the ATP. welds are fantastic and fit perfectly. hell, new ATPs are 360.

      but anyways, u can buy a cat for a decent price http://www.clubrsx.com/cr/VIB-...oogle

      this thing flows REALLY well and i used it on my last car plus helped my bro install alot of these. good construction and last for a long time with no rattles or ****.

      2006 Audi A3 | 2.0T | 6MT | APR Stage 2+ | Fully loaded ECU | FK grill | EJ CAI | BSH TBP |EJ DV Reloc. | Eurojet TBE | EuroJet Catch Tank | Cross drilled and Slotted Rotors | EBC "Redstuff" Kevlar | Raceland Coilovers | Forge Side to Side Short Shifter | Forge Front to Back Short Shifter | Devil's Own DVC-30 Methanol injection | BSH RSB | BSH Motor mount Kit | 42 DD Shifter Bushings | HPFP Stage 1 upgrade |

    28. Member applen's Avatar
      Join Date
      Sep 26th, 2005
      Location
      Boulder, CO
      Posts
      705
      Vehicles
      had: '92 urS4, 07 GTI, '92 16V B3 Wagon, '74 914 now: '86 QSW
      11-19-2009 03:13 AM #28
      Quote, originally posted by Josein06GLI »
      700 bucks saved, wheres the problem? lol

      well there is that whole global warming thing we got goin on here... thanks for your generous contribution


    29. 11-19-2009 09:38 AM #29
      Quote, originally posted by applen »

      well there is that whole global warming thing we got goin on here... thanks for your generous contribution

      Global Warming? uncatted 2.0T VW's hardly contribute to that isht. Things like HUGE Factories & Chemical Plants etc... etc... take their tool on the enviornment.

      Sold the VAG COM

    30. Member Krieger's Avatar
      Join Date
      May 5th, 2009
      Location
      Orlando, FL
      Posts
      4,182
      Vehicles
      Turbocharged 2004 Civic SI with K20/K24 engine swap, 2006 Audi A3
      11-19-2009 10:50 AM #30
      Quote, originally posted by rippie74 »

      Global Warming? uncatted 2.0T VW's hardly contribute to that isht. Things like HUGE Factories & Chemical Plants etc... etc... take their tool on the enviornment.

      this. the 2.0T is a very clean engine, except for running rich.

      BUT, its still better if we all had cats... but hey, what are u gonna do about it.

      2006 Audi A3 | 2.0T | 6MT | APR Stage 2+ | Fully loaded ECU | FK grill | EJ CAI | BSH TBP |EJ DV Reloc. | Eurojet TBE | EuroJet Catch Tank | Cross drilled and Slotted Rotors | EBC "Redstuff" Kevlar | Raceland Coilovers | Forge Side to Side Short Shifter | Forge Front to Back Short Shifter | Devil's Own DVC-30 Methanol injection | BSH RSB | BSH Motor mount Kit | 42 DD Shifter Bushings | HPFP Stage 1 upgrade |

    31. Member SmithersSP's Avatar
      Join Date
      May 24th, 2006
      Location
      Charlotte, NC
      Posts
      4,902
      Vehicles
      REVO STGIII S3 K04 06' PG GLI, C2 97' GLX
      11-19-2009 10:56 AM #31
      Actually Rippie I believe that automobiles are the source of the majority of air pollution today. Couple this with the fact that my FSI run 12:1 at WOT and that leaves the potential for a large quantity of co2 and NOx emissions.

      P.S. As an engineer I believe that we'll all screwed unless we change our primary energy source period. In the long term one catless dub won't level a rainforrest. That being said a catless car is worse for the environment than a catted one.


      Modified by SmithersSP at 7:58 AM 11-19-2009
      Chapter 11 Dubs
      Revo STGIII Kegerator
      Quote Originally Posted by jhines_06gli View Post
      I fix Pete's car to keep cold, cheap beer flowing for the club at shows.

    32. Member Josein06GLI's Avatar
      Join Date
      Jun 28th, 2008
      Location
      San Diego, Ca
      Posts
      3,875
      Vehicles
      2012 Audi , 2006 VW Jetta GLI, 1989 MK2 GTI VR6
      11-19-2009 01:19 PM #32
      thanks rippie for the defense and i just looked at paypal and i paid 180 for the dp and it spend like 60 bucks on tools to install myself so almost 3 bills. ok not wanting to fight or argue via internet this is a forum and everyone does have an opinion i stated mine. love it or hate i dont care
      2006 BMP VW JETTA GLI DSG some coils, some bolt ons and some wheels.
      1989 VW GTI 2.8l VR6 some coils, some bolt ons, and some wheels.
      2012 Audi all stock, its hers. she dont want me messing with it...yet.

    33. Member bostonaudi1's Avatar
      Join Date
      May 13th, 2006
      Location
      Charleston, SC
      Posts
      1,040
      Vehicles
      2008 VW GTI, 1995 BWM M3
      11-19-2009 08:22 PM #33
      Quote, originally posted by Krieger »
      stock cats are small, thick, and super restrictive.

      i have an ebay pipe cuz it works, but im gonna get a 200 cell metallic cat. might be from magnaflow, but i like random technology too.

      The pre-cat on the Mk5 is definitely a restriction, I run an AWE downpipe w/metal cat and my engine revs ridiculously fast and makes a ton of power with the stock K03. Taking that first one out is key. I feel no need to run totally cat free.

      The cheapo $100 ceramic cats that usually come w/aftermarket systems are sometimes more restrictive than factory cats, which aren't always that bad.

      A cat is a modern miracle invention, for a slight restriction, it cleans the heck out of the exhaust. Anyone remember seeing pictures of LA basin from the 60's during a smog inversion?





      Modified by bostonaudi1 at 8:30 PM 11-19-2009

      2008 GTI Option 0 - Daily driver and track car (#62)
      PCA HPDE Instructor
      http://www.jkautomotive.net/

    34. 11-19-2009 10:15 PM #34
      i have a catless 42DD 3" setup on my mk5 gti. I went this route cause im a cheap ass and it was much cheaper to go catless.

      The stock cats main downfall is because its RIGHT after the turbo. a QUALITY highflow aftermarket cat vs catless gains are marginal at best when talking about running a ko3 or ko4 turbo.

      please spare us the 1990 cat analogies guys.............that is beyond outdated moot point.

      I have a customer with a BMW Z-3 that did some insane custom turbo, meth injection, built motor, HUGE custom wheels out back(he's an engineer and did the majority of the stuff himself). I asked him his thoughts on why with all that power over 500 wheel. he was still using a stock cat welded into his custom exhaust..........he said you know I did a test pipe setup on the dyno and saw MAYBE 10 crank hp......he felt that was not worth the trouble in the scheme of things seeing as how he could not hook at all anyways!

      FWIW im going to add a cat to my setup because my garage smells HORRIBLE for at least 1 hour when i get home and it drives me crazy. I do back into the garage which adds to the issue.


      Modified by RABIDRABBIT1983 at 4:49 AM 11-20-2009


      Modified by RABIDRABBIT1983 at 5:59 AM 11-20-2009


    35. Member bostonaudi1's Avatar
      Join Date
      May 13th, 2006
      Location
      Charleston, SC
      Posts
      1,040
      Vehicles
      2008 VW GTI, 1995 BWM M3
      11-23-2009 05:42 PM #35
      Quote, originally posted by RABIDRABBIT1983 »

      I have a customer with a BMW Z-3 that did some insane custom turbo, meth injection, built motor, HUGE custom wheels out back(he's an engineer and did the majority of the stuff himself). I asked him his thoughts on why with all that power over 500 wheel. he was still using a stock cat welded into his custom exhaust..........he said you know I did a test pipe setup on the dyno and saw MAYBE 10 crank hp......he felt that was not worth the trouble in the scheme of things seeing as how he could not hook at all anyways!

      FWIW im going to add a cat to my setup because my garage smells HORRIBLE for at least 1 hour when i get home and it drives me crazy. I do back into the garage which adds to the issue.

      That factory BMW cat is most likely metal core. It is well known fact that the factory exhaust on the E36 M3's make all the power you'll ever need, most aftermarkets for that car do nothing other than add noise...

      2008 GTI Option 0 - Daily driver and track car (#62)
      PCA HPDE Instructor
      http://www.jkautomotive.net/

    Page 1 of 2 12 LastLast

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •