Perhaps it was another forum, but I thought Jeff made it clear that he had owned a 991 Turbo with a EP already and wanted something louder this time around.

 

Thank you for giving our Sport Cats a try, I'm sorry it was not exactly what you were looking for.

Just had a chat with our in-house tuner, Steve. The 991 Turbo platform does not have a MAF sensor, it uses a speed density sensor. As volumetric efficiency increases so does power and is not limited short of knocking or temperature related pinging. We tested this repeatedly on our Dynojet. When saying "Any 991 Turbo" this includes the 991.1 Turbo where there is no doubt that exhaust systems alone do increase peak power. In the graph below you'll see you gain +12.87 peak wheel horsepower and +39.5 peak wheel ft/lbs of torque with 200cell HJS sport cats installed and our X-Pipe.

We are growing more and more dedicated to producing honest power results and just yesterday installed a new module on the dyno to ensure it is an industry leading platform to showcase our gains from hardware and/ or tuning.

The entire Fabspeed team is always available to discuss any tuning or hardware questions if you were to have any please let us know.

 

Yeah I have to agree with this because I had Cobb measure my car with bolton's only which included FVD exhaust, headers, IPD Y-Pipe, IPD Plenum and ByDesign IC's. In that config it measured 502 whp which compared to 493whp with the FVD piggyback, headers and exhaust back in September. Without the piggyback in September the max hp with boltons only in sport plus was 474 hp and in normal mode it was 466. So I think the ECU will allow for airflow to make more horsepower as long as the safety parameters are not exceeded. The data I have seems to suggest that is the case. In the top graph the blue is Cobb Stage 3 before custom tuning and the red is boltons only. In the bottom The red is with the FVD piggyback, FVD headers and FVD exhaust. Blue is normal mode without the piggyback and green is sport plus without the piggyback. Point being that with the ICs and Y-Pipe there was an additional 26whp added. I don't know what my car is without the exhaust but I believe it would be less because it has 200 cell cats along with that exhaust.

 

Both are correct. There are limits that get hit and corrected for, but it takes a few hardware mods to get there. So bolt-ons help by increasing efficiency but their max potential can only be realized if the car is calibrated. Above that you can dial in or even custom tune further to take full advantage of the hardware changes. This is true on any tune factory or aftermarket depending on what it's calibrated for.

 

The other thing we see is that some cars just make more power than others. I think the later models do better even before the .2. I have a launch car and it consistently is slower and shows less power than even other 14's and certainly the 15s and 16s that have been showing up on the board and are still .1s. Porsche is improving the manufacturing process as well as what they put in the ECU. They don't give you ECU bumps later on. I had the AWD module switched out and that didn't do anything for my ECU. I am sure the newer .1s are faster and more powerful than my 9/13 build crate (by comparison).

 

I have the EP. Listen to this compared with others on a decent pair of speakers not a smartphone.
The character of this exhaust is perfect in my "opinion"

Exhaust is so personal. Listen to different clips on all exhaust manufacturers on decent speakers or if possible in person. Dont take my opinion or anyone else's affect your decision. Listen to what sounds best to you.

 

I doubt you can get much louder than EP without going catless. If you want super loud Fabspeed catless is about as loud as their is -- other than the Bazooka shooter exhaust with no muffler.

 

The following exhausts are louder (in order) than EP and have cats:

Kline Loud
Fabspeed
GMG
BBi
Sharkwerks/stock cats
Sharkwerks/ Fabspeed cats

Drone increases with each on down to the Sharwerks/Fabspeed cats, which solicited neighbor complaints from *startup* and was louder than my C6 Z06 with headers, cats, and bullets and rattled my teeth at 1800 rpm.

There is a real art to creating a great sound in an exhaust while notch filtering the 350-500 hz in-car resonance. EP stayed on the conservative side right next to Kline. Kline made a louder prototype for me that still has less drone than stock. GMG is good except on long 60mph uphills, and BBi has more drone than stock but has a really fun viscous sound.

The Sharkwerks has more drone than stock, but uses the stock cats to dampen the drone a bit. I thought I could move to a stage 2 tune if I added the Fabspeed cats, but the volume and drone increase was *incredible*. If the stock exhaust wasn't as poor as it is at drone mitigation, I would have tried the Fabspeed cats and the stock muffler. I swap all my exhausts myself and it's just time. But I htink it would have been much too drone-ey.

If others are interested in doing some calibrated noise testing in their cars and would throw $50 at it, I'd also be willing to buy the SoundMeter and Frequency Analysis pack by Faber Acoustical for the iPhone if people want to measure drone, total sound levels, etc for multiple exhausts. I know there's some error, but I believe we can get moderately scientific about it and remove some of the subjectivity.