TopGear 981 GT4 Catless Header Review
#61
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Generally for emissions inspections you are allowed a certain number of "Not Ready"s. Here in TX emission test counties it is one. This is to make sure you don't just clear your CEL in the parking lot before you get an inspection.
Softronic tells me they can handle the CEL, but there will still be monitors that don't go ready. In this case, I will not be able to pass inspection. I'm not worried about visual inspection because in my experience they are never able to even find the engine. Every time, pull in the car, pop the hood, they see nothing, say "F it" and move on.
#62
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I emailed Sierra Racing about availability last month. They got a few sets in late December, expecting more late February or March.
#63
Instructor
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ECU's have monitors for various systems connected for them. When you reset the CEL or disconnect the battery these monitors are set to "Not Ready". Once each monitor has gone through its test cycle successfully it changes to "Ready".
Generally for emissions inspections you are allowed a certain number of "Not Ready"s. Here in TX emission test counties it is one. This is to make sure you don't just clear your CEL in the parking lot before you get an inspection.
Softronic tells me they can handle the CEL, but there will still be monitors that don't go ready. In this case, I will not be able to pass inspection. I'm not worried about visual inspection because in my experience they are never able to even find the engine. Every time, pull in the car, pop the hood, they see nothing, say "F it" and move on.
Generally for emissions inspections you are allowed a certain number of "Not Ready"s. Here in TX emission test counties it is one. This is to make sure you don't just clear your CEL in the parking lot before you get an inspection.
Softronic tells me they can handle the CEL, but there will still be monitors that don't go ready. In this case, I will not be able to pass inspection. I'm not worried about visual inspection because in my experience they are never able to even find the engine. Every time, pull in the car, pop the hood, they see nothing, say "F it" and move on.
Bummer! I’m in Washington state which have eliminated emission testing altogether. There are mini-cats you can try which should work great with the Softronic tune. I think he just widens the parameters for the second O2 sensors which worked fine for me until I went auto crossing. I would always get a CEL during or on the drive home. For me it was more just an annoyance so he deleted the secondary O2’s completely. At any rate, I found some mini-cats for around $100 for the pair… just do some searching around. They looked about the same as the other higher priced ones.
Try Prosport Performance…
Last edited by NoSubstitute981; 02-03-2024 at 12:39 AM.
#65
Instructor
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Budgeezer (02-21-2024),
_GTS_Panda (02-21-2024)
#68
#69
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The car is finally done, and I will pick it up. The shop mentioned how well the product seems to be made. But what ended up taking so long was that Soul did not send gaskets for the headers and instructed the shop to reuse the gaskets from the OEM headers. They were shocked because they didn't think this was a best practice. After inspecting the gaskets, they were uncomfortable reusing the original ones and had Porsche send new ones. They said it was the equivalent of reusing a condom. Can it be done? Sure. Should it be done? No. The shop is Dobson Stuttgart in Seattle, and they are very reputable, so I took their word for it. I will let you know soon!
And yea. I did chicken out about the catless headers. After tons of research and talking with people, I don't think the hassle was worth the nominal gains over the high-flow sport cats.
And yea. I did chicken out about the catless headers. After tons of research and talking with people, I don't think the hassle was worth the nominal gains over the high-flow sport cats.
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Budgeezer (02-21-2024)
#70
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TG set on the way, but it will be a while before I can install them. I want to cut out the mini-cat first. Guess I need to order plugs and coil packs to do while I have easy access.
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Budgeezer (02-21-2024)
#71
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Finished the install yesterday, but waited for dry weather to try them out today. Initial feeling is that the engine revs more freely, with smooth, progressive power at part throttle street driving, and a pleasing sound. It definitely gets more rowdy at WOT and high rpm, more “race car”. My butt dyno isn’t calibrated well enough to measure the power gain, so that will have to wait until the next track day. It does seem to be stronger in the mid range, but it could be the sound…..
Installation was pretty straightforward, although I did have to make a parts run to pick up some bolts for the outlet flange. Supposedly the Soul headers come with the bolts…. I did find that using a E14 socket instead of E12 gave just enough slop to allow all of the flange bolts to be accessed without binding. The hardest part was getting the O2 sensor wiring out and rerouting it after the headers were in place. I do have a lift, so I didn’t have to do the job lying on my back.
Installation was pretty straightforward, although I did have to make a parts run to pick up some bolts for the outlet flange. Supposedly the Soul headers come with the bolts…. I did find that using a E14 socket instead of E12 gave just enough slop to allow all of the flange bolts to be accessed without binding. The hardest part was getting the O2 sensor wiring out and rerouting it after the headers were in place. I do have a lift, so I didn’t have to do the job lying on my back.
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Budgeezer (03-11-2024)
#72
Instructor
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Finished the install yesterday, but waited for dry weather to try them out today. Initial feeling is that the engine revs more freely, with smooth, progressive power at part throttle street driving, and a pleasing sound. It definitely gets more rowdy at WOT and high rpm, more “race car”. My butt dyno isn’t calibrated well enough to measure the power gain, so that will have to wait until the next track day. It does seem to be stronger in the mid range, but it could be the sound…..
Installation was pretty straightforward, although I did have to make a parts run to pick up some bolts for the outlet flange. Supposedly the Soul headers come with the bolts…. I did find that using a E14 socket instead of E12 gave just enough slop to allow all of the flange bolts to be accessed without binding. The hardest part was getting the O2 sensor wiring out and rerouting it after the headers were in place. I do have a lift, so I didn’t have to do the job lying on my back.
Installation was pretty straightforward, although I did have to make a parts run to pick up some bolts for the outlet flange. Supposedly the Soul headers come with the bolts…. I did find that using a E14 socket instead of E12 gave just enough slop to allow all of the flange bolts to be accessed without binding. The hardest part was getting the O2 sensor wiring out and rerouting it after the headers were in place. I do have a lift, so I didn’t have to do the job lying on my back.
Yep! Same experience here. I did mine on the ground however…
Soooo… did you get a ECU flash? Get mini cats? Your photo doesn’t look like a standard Cayman.
GT4?
At any rate, with the flash I noticed a fairly noticeable increase in low to midrange boost over stock. Also I just installed BMC filters and that seemed to make a slight difference as well. If nothing else, the sound is pretty cool. I’m running 9’s in front and 11’s in the rear with 255 and 285 (RE71 RS tires) respectively and nothing seems to shake this thing. Can’t wait to get it on the track!
Last edited by NoSubstitute981; 03-11-2024 at 08:00 PM.
#73
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My car is a GT4 with the Softronic tune. I cut out the “defoulers” (mini cats) prior to installation. 40 years ago I might have done it on the ground, but if I didn’t have the lift I would have paid somebody else..
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#74
Instructor
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I chose not to install them either… we don’t have emissions here anymore so no biggie.
You must be older than me. I’m only 53 so can still lift and creep, lol. Not much longer I’m afraid but can still get it done. Jealous of your lift… bucket list!
Glad you like the outcome. They really are nice headers.
To the reluctant… it really boils down to your comfort level. Personally, I wouldn’t purchase any kind of header replacement that includes a converter. Money wasted IMO!
Go all-in or don’t bother. The factory stuff isn’t bad at all. I don’t think there’s much to be had by installing, eh hem, high flow cat headers. My opinion of course but I wouldn’t waste my $. Better to buy better tires… If you really want the most out of your car then just get the tune. You won’t be disappointed.
#75