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Fabspeed Mini-cat used to fool the post cat O2 sensor
Fitment/Quality Top notch quality headers with meticulous welds and perfect bolt-on fitment to the stock PSE! The post O2 mini-cat was a tight fit on the driver side, angling pretty close to the oil filter housing. The subframe blocked the post O2 mini-cat from fitting on the passenger side so we swapped the position of the pre and post cat O2 sensors on the header, no big deal at all. These race headers are substantially lighter than the stock headers which are needlessly burdened with catalytic converters and shielding.
Sound:
Absolutely AMAZING. The stock GT4 already had a very deep growl with the PSE but I felt it was too silent inside the car. After I put these headers on, I can confidently say that the sound level inside and outside the car has increased by 50% percent! Better yet, the race headers do not change the baritone sound signature of the stock PSE instead it accentuates it even more like a veil being removed to uncover the pure grit of the 9A1 motor. The aggressive sound with these race headers reminds me that I bought a GT car not some base model 911 cruiser. Furthermore, this is the perfect mod for me because personally I’m not a fan of high pitch sounding exhausts as most of the aftermarket catbacks for the GT4 are.
Driving impressions:
You definitely feel a kick in the mid-range and top end. So far with 50 miles I have not had a CEL (your mileage may vary). There is absolutely no drone in the cabin and it is dead silent during cruising but the moment you step on the accelerator pedal, it unleashes this sudden bark out of nowhere and continues with a stentorian wail until redline.
Overall I am EXTREMELY satisfied with this purchase and it substantially enlivens the sporty nature of this car. I am a person who firmly believes in supporting American businesses first (so I bought a German car) and if you don’t, you should be ashamed of yourselves! Fabspeed, I take my hat off to you - you guys have certainly earned yourselves a very loyal customer!
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1/2017 update:
Loaded up the Cobb Stage 2 OTS map last week, very nice bump in power
Today I got the IPD Plenum/82mm GT3 TB installed. See it as my big '**** you' to Porsche for putting a 74mm TB on the GT4 when the 991.1S came with the 82mm TB stock.
Impressions: The Cobb Stage 2 OTS tune integrated flawlessly to the IPD Plenum/82mm TB, no codes, no stumble, The stock exhaust sounds 20% louder and there is a very nice bump in power in the mid-range and a smaller bump up too. There is an increased in air induction sound and the throttle response is more lively. The car pulls smoothly to no end without any dips in the midrange anymore (the Fabspeed headers themselves smoothed out 95% of it). Highly recommended modification to complete your bolt ons Don't just settle for that 74mm TB that Porsche purposely gimped the car with
Thanks for the writeup as this is an option I'm seriously considering. And good to hear that you haven't triggered a CEL (yet); do you know if any other GT4 owner has had a CEL problem with the same headers and mini-cats? Perhaps Fabspeed could jump in here and fill us in ...
Thanks for the writeup as this is an option I'm seriously considering. And good to hear that you haven't triggered a CEL (yet); do you know if any other GT4 owner has had a CEL problem with the same headers and mini-cats? Perhaps Fabspeed could jump in here and fill us in ...
Fabspeed has just released their mini-cats so not enough data yet
Originally Posted by usctrojanGT3
Did you get the 45 degree or the 90 degree fitting? The single spacer or two spacers?
I believe the 45 degree fitting, single spacer with the mini-cat at the end
Originally Posted by monochrom3
Nice! How are the pops & burbles when you come off throttle as compared to stock?
The pops and burbles are more prominent but they sound natural with more dimension, never synthetic
Fabspeed Mini-cat used to fool the post cat O2 sensor
Fitment/Quality Top notch quality headers with meticulous welds and perfect bolt-on fitment to the stock PSE! The post O2 mini-cat was a tight fit on the driver side, angling pretty close to the oil filter housing. The subframe blocked the post O2 mini-cat from fitting on the passenger side so we swapped the position of the pre and post cat O2 sensors on the header, no big deal at all. These race headers are substantially lighter than the stock headers which are needlessly burdened with catalytic converters and shielding.
Sound:
Absolutely AMAZING. The stock GT4 already had a very deep growl with the PSE but I felt it was too silent inside the car. After I put these headers on, I can confidently say that the sound level inside and outside the car has increased by 50% percent! Better yet, the race headers do not change the baritone sound signature of the stock PSE instead it accentuates it even more like a veil being removed to uncover the pure grit of the 9A1 motor. The aggressive sound with these race headers reminds me that I bought a GT car not some base model 911 cruiser. Furthermore, this is the perfect mod for me because personally I’m not a fan of high pitch sounding exhausts as most of the aftermarket catbacks for the GT4 are.
Driving impressions:
You definitely feel a kick in the mid-range and top end. So far with 50 miles I have not had a CEL (your mileage may vary). There is absolutely no drone in the cabin and it is dead silent during cruising but the moment you step on the accelerator pedal, it unleashes this sudden bark out of nowhere and continues with a stentorian wail until redline.
Overall I am EXTREMELY satisfied with this purchase and it substantially enlivens the sporty nature of this car. I am a person who firmly believes in supporting American businesses first (so I bought a German car) and if you don’t, you should be ashamed of yourselves! Fabspeed, I take my hat off to you - you guys have certainly earned yourselves a very loyal customer!
My superb and "anonymous" friend, thank you VERY much for this superb and detailed review! It is an absolute pleasure working with you, and I am beyond thrilled to find the results of this configuration met the goals you had as expected
This information is precious to those in the community looking to make an educated decision on taking their driving experience to the next level. I wish we all had more of you good sir
I am very much looking forward to our continued relationship and striving to perfect your rides
Originally Posted by 4Nines
Sounds amazing! Thanks for sharing.
Originally Posted by usctrojanGT3
Did you get the 45 degree or the 90 degree fitting? The single spacer or two spacers?
Originally Posted by monochrom3
Nice! How are the pops & burbles when you come off throttle as compared to stock?
Originally Posted by 4carl
What was the cost for the system with the install? looks good.. thanks carl
PM's sent over to you guys to answer any questions you have on our products, and look forward to working with you as well!
05-19-2016, 05:06 PM
Fabspeed Race Header Review, O2 Mini-cats, no CEL, have your cake and eat it too!
The stock exhaust sounds 20% louder and there is a very nice bump in power in the mid-range and a smaller bump up too. There is an increased in air induction sound and the throttle response is more lively. The car pulls smoothly to no end without any dips in the midrange anymore (the Fabspeed headers themselves smoothed out 95% of it). Highly recommended modification to complete your bolt ons 
