Secondary Cat Removal, Really Worth It?
#46
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Tom,
Yeah, I never saw the point of polished exhaust pipes. Not only will every single inspector see them instantly, who the F cares to pay extra for a polished pipe that sits underneath the car and gets mud, rain, salt etc all over it?
No, I don't have a tune yet. Maybe someday I will but (and I can't believe I'm saying this) the truck has plenty of power as is. Plus I keep finding other ways to spend $1000....
Yeah, I never saw the point of polished exhaust pipes. Not only will every single inspector see them instantly, who the F cares to pay extra for a polished pipe that sits underneath the car and gets mud, rain, salt etc all over it?
No, I don't have a tune yet. Maybe someday I will but (and I can't believe I'm saying this) the truck has plenty of power as is. Plus I keep finding other ways to spend $1000....
#47
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Depends on whether they're just transportation or more than that. My nicer cars (RUF 997 and Cayenne) are pretty much spotless inside, outside, and on the top and bottom. They could enter a show at any time and probably do OK. On the 997, the mufflers and exhaust are visible through the rear bumper vents, not so much on the Cayenne but polishing them makes them look better and makes them easier to keep clean. To each their own, but I like my stuff to look as good as it can and take the best care of it I'm able to, both mechanically and cosmetically.
Last edited by Petza914; 05-19-2017 at 07:55 AM.
#48
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Yeah, you'll never find me wasting my time using Q tips cleaning my car and entering a concours with it.
More power to those that enjoy that stuff but to me it's a gigantic waste of time.
I just don't see the point of a polished pipe that sits underneath the truck, that gets seen by no one and will simply get filthy everytime you drive...
More power to those that enjoy that stuff but to me it's a gigantic waste of time.
I just don't see the point of a polished pipe that sits underneath the truck, that gets seen by no one and will simply get filthy everytime you drive...
#49
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I certainly agree about the bling factor. I am not a fan of advertising that I have removed federally-mandated emissions equipment.
Docwyte, does your 2006 TTS have an ecu tune?
From what Scott at Softronic told me, the secondary cat delete does allow the turbos to spool faster and generates more hp and tq. He said that it will be quite noticeable with the tune. All the other bolt-ons are expensive bling: the intake, the primary cat delete, etc... Unless you are willing to spend big bucks on headwork, upgraded turbos and willing to let longevity go, a responsible tune and the secondary cat delete is really the limit. The other modifications are going to run into five-digit territory.
Cheers,
TomF
Docwyte, does your 2006 TTS have an ecu tune?
From what Scott at Softronic told me, the secondary cat delete does allow the turbos to spool faster and generates more hp and tq. He said that it will be quite noticeable with the tune. All the other bolt-ons are expensive bling: the intake, the primary cat delete, etc... Unless you are willing to spend big bucks on headwork, upgraded turbos and willing to let longevity go, a responsible tune and the secondary cat delete is really the limit. The other modifications are going to run into five-digit territory.
Cheers,
TomF
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#50
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If you're only deleting 2ndary cats, no need for resonator. There is no rasp....just a little more volume. I personally would like it louder but it's perfect for everyone else in the family. I have HHR's. They're just pipes...no need to pay extra.
2ndary delete, ecu tune and new DV's and be done with it
2ndary delete, ecu tune and new DV's and be done with it
#51
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Around 1989 I bought a 1983 Rx-7 cheap because it was slow and the owner didn't know why. 34k miles, black metallic, burgundy interior, flawless. Topped out at about 70mph. I had heard that rotaries clog cats, so I loosened but didn't remove the two nuts that attached the header to the cat so that the flange was free to spread open with backpressure. I finished doing this at about midnight in my parent's quiet neighborhood and went for a test drive. The car was transformed, it went like a rocket (a deafening rocket), and loudly backfired and ejected a column of flame on every shift. Success! I came home to a livid father standing in the driveway who had heard the noise during the entire drive on my 2mi test-circuit. The next day, I used a giant 18"chisel to bash out the guts of the cat and reassembled. Looked 100% stock. Inspections from that point onward generally involved private service stations and bribes. I tell this story only to show that I am not an emissions prude.
Later got an 89 944, when I started tracking the car, thought about removing the cats, but then learned that the factory Porsche teams raced cats-on, so I never bothered. Participated in many Driver's Ed events as well as AutoX, generally won my class (P7) for the two years that I raced. Got rid of that car at about 175k, still running great, still passing emissions.
Currently have a 93 968, still has the cats on. It's old enough that in AZ it gets smogged by the state on a dyno at highway speeds with a hose on the tailpipe. 24yo, 157k on the clock, still passes just fine.
I'm not going to say that it's foolish to remove perfectly good working cats for a negligible or non-existent improvement, but....
c
Later got an 89 944, when I started tracking the car, thought about removing the cats, but then learned that the factory Porsche teams raced cats-on, so I never bothered. Participated in many Driver's Ed events as well as AutoX, generally won my class (P7) for the two years that I raced. Got rid of that car at about 175k, still running great, still passing emissions.
Currently have a 93 968, still has the cats on. It's old enough that in AZ it gets smogged by the state on a dyno at highway speeds with a hose on the tailpipe. 24yo, 157k on the clock, still passes just fine.
I'm not going to say that it's foolish to remove perfectly good working cats for a negligible or non-existent improvement, but....
c
#52
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Recently picked up some lightly used HHR resonated 2nd cat bypass pipes and had them installed on a 2014 CTTS. Got them for $300 and another $100 for install, so total was about half new ($750 new + $100 install). Install was easy, without complications, and build quality of pipes is good. BTW, original owner said he was selling these and doing complete upgrade of exhaust to get the sound he desired.
Sound is different than stock and most noticeable (to me anyway) at idle. More bass and throaty. No drone when driving around. No rattles, shakes, etc. Haven't dyno'ed to see if power/torque increase. No inspections in my state to worry about. Overall, I'd say the sound change is not that dramatic.
Would I do it again and do I think it was worth it? Probably wouldn't do if I had to pay full retail. Happy with result at price I paid. YMMV.
FWIW, my other car is a 2015 Boxster GTS with PSE and what 'sold' me on the car was the PSE. Appeals to the teenage boy in me to hear the pops and gurgles. Not as big a deal on the CTTS as it's my daily driver.
Sound is different than stock and most noticeable (to me anyway) at idle. More bass and throaty. No drone when driving around. No rattles, shakes, etc. Haven't dyno'ed to see if power/torque increase. No inspections in my state to worry about. Overall, I'd say the sound change is not that dramatic.
Would I do it again and do I think it was worth it? Probably wouldn't do if I had to pay full retail. Happy with result at price I paid. YMMV.
FWIW, my other car is a 2015 Boxster GTS with PSE and what 'sold' me on the car was the PSE. Appeals to the teenage boy in me to hear the pops and gurgles. Not as big a deal on the CTTS as it's my daily driver.
#53
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bringing this post to live, as your truck is close to what i have , mine is 2016 CTT with the PSE, would love to here a sound clip if you have the chance, thank you
#55
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Should I go with HHR or Fabspeed? Is the Fabspeed really worth $200 more? I just bought an 09’ Cayenne GTS with 50k miles. Car has a hesitation at low RPMs, like a bump bump bump type of hesitation. So I changed out all the spark plugs, coils, air filters and cleaned the MAF sensors. Still have same hesitation. Of course no codes on the dash. Could it be the fuel filter? Or maybe can’t breathe good enough due to old cats and installing bypass pipes would fix this? Any suggestions?
#56
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I’m trying to decide between the Fabspeed and HHR secondary cat bypass pipes. Does anyone know if these actually sound different? Was also thinking about the HHR resonated version. Anyone have any advice?
#57
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Yes, save your money and get the HHR pipes. They're pipes guys, nothing special here. Unless you have some sort of fetish to have polished pipes where nobody can see them, in which case spend the extra money for the Fabspeeds.
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#58
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Should I go with HHR or Fabspeed? Is the Fabspeed really worth $200 more? I just bought an 09’ Cayenne GTS with 50k miles. Car has a hesitation at low RPMs, like a bump bump bump type of hesitation. So I changed out all the spark plugs, coils, air filters and cleaned the MAF sensors. Still have same hesitation. Of course no codes on the dash. Could it be the fuel filter? Or maybe can’t breathe good enough due to old cats and installing bypass pipes would fix this? Any suggestions?
#59
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It didn't come from the factory doing bump-bump-bump, if it's doing that - something is wrong and bypass pipes are very unlikely to do a thing to make it better. A restrictive cat would cause problems at higher flow velocities - not at low RPM. I'd suggest getting a Porsche specific scan tool and see what's actually going on rather than throwing money at it more or less at random.
Secondary cats aren't monitored by any sensors which is why replacing them is easy to do without any programming - No way those are causing your issue.
I don't think there's a significant difference between the HHR and Fabspeed bypass pipes either - if the HHR are less expensive, I'd go with those. I also don't think you need the Resonated versions unless you're eliminating the primary cats and don't want the exhaust too loud. The secondary cat delete adds just a little bit of sound, but not too much. A nice subtle mod IMO. I run the Fabspeed secondary cat bypass pipes but purchased them in the Marketplace. A also run the HHR cold air intake. Both companies make quality products.
#60
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It didn't come from the factory doing bump-bump-bump, if it's doing that - something is wrong and bypass pipes are very unlikely to do a thing to make it better. A restrictive cat would cause problems at higher flow velocities - not at low RPM. I'd suggest getting a Porsche specific scan tool and see what's actually going on rather than throwing money at it more or less at random.