[nineball]

so i had been contemplating getting the fabspeed supercup turbo back exhaust system w/ sport cat. on their website it states it will result in a gain of 10whp and 13ft-lbs. i also saw on their site they are offering a tuning option ($1,600 and you must send them your ECU) which claims to have an increase of 60whp/80ft-lbs for the 2.0 and 55whp/80ft-lbs for the 2.5. so the pair states a total increase of 70whp/93ft-lbs for the 2.0 and 65whp/93ft-lbs for the 2.5.

then i got this link in an email today.

it states the dyno shows 4whp/13ft-lbs increase for the exhaust and then 23whp/60ft-lbs with the tune, all on a 2.0. here is where i am confused. how can they go from advertised 70whp/93ft-lbs down to to 27whp/73ft-lbs on a dyno (assuming the tune added it's numbers to what the exhaust had done already, because if not the increase gets even smaller)? that's a pretty significant difference between advertised increases and real world application on a dyno (62% and 13% less respectively, 68% and 36% if the "tune"dyno numbers encompass both tune and exhaust). am i missing something?

 

[TEST DRyVer]

I'll explain this as I also had a hard time understanding this in the past as well. The short answer is yes, you don't know how to do math ???. I'm kidding of course... The numbers stated on the dyno sheet are Peak dyno numbers. Example: if peak horsepower on a base car is 300hp and peak gain after modifications are 320hp, then it's only showing a 20hp bump, correct? Yes, but if you look on the actual dynograph, you'll see an area where the difference between stock and modified car would 80hp. They then advertise the 80hp bump instead of the 20hp peak bump. I hope this clarified things. Truth is, when you're actually driving the car, you feel the big 80hp bump instead of the 20 peak horsepower bump.

 

[ZuffenHouseRules]

I think there is some misunderstanding here. The 718 on the dyno in the video is an S (note the red brake calipers). While the title captions don't explicitly call it out as an S, you'll notice that the 718 tune page of the Fabspeed site nowhere refers to "S", only to 2.0 and 2.5 results.
http://www.fabspeed.com/2017-porsche-718-boxster-cayman-fabspeed-ecu-tune/

But the real proof the car in the video is not a 2.0 with after-market painted calipers: their 341rwhp stock result is right in line with what other tuners (AWE and Cobb) have shared for their 718 S baseline runs. All the other Fabspeed quoted hp and torque gains can then reference either the Porsche factory ratings (engine/crank hp at the flywheel) or their own dyno baseline results at the rear wheels converted to crank hp (at least 15% higher due to drivetrain losses). So lots of room for ambiguity, and why all tuner claims for increased power have to be scrutinized starting with their baseline dyno readings. Claims of huge increases are likely based on subtracting grossly-understated factory ratings from after-tune rwhp dyno results converted to crank hp -- in other words, subtracting apples from oranges.

That 341rwhp stock dyno run on the video and graph is a car making around 400hp from the factory. Adjust tuner claims accordingly -- although the Fabspeed video and included dyno chart are quite clear....I think it's their website claim for "+55hp" which perhaps translates to "55hp above factory rating".

 

[Andros X Thomson]

It may be accurate, with the stock turbo on the 2.0, that the max gain is 80, but peak is ~20 because the k04 on the 2.0 is approaching max efficiency. It can likely hit 26 psi, but would drop to ~18 around redline if pushed to max efficiency range, if I remember correctly. So the car will be quicker overall, and as a DD, you will really feel it since most people don’t go to redline between shifts.