You might find my review of the Vektor headers useful: https://rennlist.com/forums/991/1234...er-review.html

I have found the combination of the Vektor headers plus the PSE to be a great solution.

Something not emphasized enough I think is that different people will tolerate different degrees of drone.

I did try the Vektor headers plus Vektor cats, and for me there was drone with valves open while cruising. I also tried Vektor headers with Akrapovic exhaust, resulting in the same thing: specifically drone at 2-3k rpm when valves open, exactly at everyday cruising speeds. For me, this was a no go. The drone only occurred with headers PLUS cats or Akra, but not with the headers alone.

To me, drone while cruising at highway speeds with valves open took away from my enjoyment of the car. You might say well just don’t use with valves open, but for me at least, I didn’t want to reduce enjoyment of or feel restricted in my ability to use open PSE whenever I wanted. So I did not end up going with cats or Akrapovic.

I’ve kept only Vektor headers. Which tells you how much I love them vs. only cats or exhaust. While the cats improve sound by opening things up, there is an environmental cost and the egg smell. Most importantly though, they don’t have the same type of flow improvements as Vektor headers: the rotary collector and equal length tubes render the turbo lag essentially nonexistent. This makes the car feel NA, but with massive torque.

That to me is the magic of the Vektor headers—they give you the best of both worlds, NA and boosted. And their customer service is phenomenal.

With the Litchfield tune and Vektor headers, there is so much instant torque, my T feels like driving an EV, except with a rumble and a glorious soundtrack.

Hope this helps.

 

If the 200 cell cats are smaller than the 600 oem cell cats = less flow. Bigger tube right ?

 

Cat counts are in CPI; Cells Per Inch. So same size with fewer CPI = improved flow.

 

Not quite, bigger isn't always better there is an optimal size for everything and you can go too big or hit diminished returns where it makes no sense to go bigger. At a point there's no reason on cat size to go bigger with extra exhaust expansion and contraction to get back down to the optimal tubing diameter. Uncorking the raw flow restriction of the density of the cat cores is important to get the performance you want. For example, here's a dyno graph of a stock set of cats and our 200cell Sport Cats. The performance gains are tangible, it won't light your pants on fire like software but you'll feel the difference. We also have a pretty slick set of Sport Headers for this platform as well, and those have also seen noticeable performance improvements you can feel. We typically have both the Sport Cats and Sport Headers in stock for anyone interested, and feel free to give me a ring anytime at 4848836197 to have an exhaust chat

Regards,
John Gaydos

991.2 PSE Sport Cats




991.2 Sport Headers

 

The 991.1 with PSE is a bit more intricate than the 991.2 with PSE, as it has three mufflers you're playing around with rather than the single muffler of the 991.2 PSE generation. From a performance perspective you are correct, when it comes to performance out of the exhaust system the best ROI for the 991.1 generation does come from a header swap (dyno below) and this is complimented very well by a software upgrade. From a sound perspective, on a PSE 991.1 the headers will make a notable sound level enhancement as it's uncorking the factory cats and the valves open flowpath is less restrictive than the 991.1 S Non PSE or Base Non PSE systems (video explanation below explaining the difference of the factory systems). That said, don't expect it to be as much a sound level difference as doing sport cats on a 991.2 PSE car, it's not quite as transformational. If your goal is primarily more sound level and an aggressive character change, you might be better off served by our 991.1 Valved Exhaust System. That will get your blood pumping when the valves open

Regards,
John Gaydos

991.1 Carrera Exhaust Differences Explained


991.1 Sport Headers



991.1 Valved Exhaust System