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This was not my experience - I used Cargraphic headers (that’s not meant to be a plug - just who I decided on). I was looking to compare the best setup (Cobb OTS 1 or 2 with headers vs. base/stock). My data shows at NO point do I dip below the base power curve and that the torque “dip” after about 2500 is substantially smoothed out. Interestingly enough, when I did the tune BY itself it had little to no impact on HP. Conversely, the headers (by themselves) has little to no impact on torque. Together, with a stage 1 tune I saw about a 7% peak increase and around 15% max for BOTH. I did this on a 9A1 2.7
**Ive said before - this was not a scientific experiment. I controlled what I could (timed it for similar barometric pressure, humidity, temp, same season/dyno/time of day, and same tank of gas). My point was NOT to validate any particular vendor or focus on actual power readings but rather the DELTA between the two)
I've seen this plenty of times before... I'm no engine builder but from what I understand from a laymen's perspective is the aggressive collection of exhaust gases serves most of its benefit at high rpm, and can actually be less efficient at low rpm. A weak attempt at a scientific analogy is there's less of a "suction" effect at low rpm like you'd get from factory headers, as the more aggressive headers are designed to help the engine "breath" when "pushed" at higher rpm. Net result is that the car makes significantly more power where it matters, so the car is faster. From experience with various tuner cars in the past, it's a barely noticeable difference when driving around town but really wakes the car up in the upper rev range.
A similar effect happens when you change to a more aggressive cam profile. It's like the powerband gets tilted on its axis. Probably the same science at work but maybe an expert can explain it better.
I've never experience upgrading headers on a 981 though so take with a grain of salt.
Well guys, there are no assumptions here, just before and after and after again dyno plots. A 2014 3.4 L Cayman S in stock form, then headers added alone, and then a protune added by Cobb themselves to maximize the performance of the car with the Cargraphics headers. Porsche penalizes the Cayman S by 25 horsepower as compared to the 911 with the same motor. This set up gets that back and an additional 17 horsepower more, along with massive gains in the torque ALL across the rev range. Final crank numbers are estimated at 367 hp and 314 tq. Not bad for a header and tune. As you can see, the headers alone make all of their power from 1800 to 5800 without any software manipulations. Porsche's ECU limits torque and no gains are seen up top until adjusted by a tune. At 3700 rpm as seen in Cobb's dyno database this set up has a peak increase in torque of 50 ft/lbs. There is about a 30ft/lbs gain in tq at each end of the dyno plot and a solid 40+ ft/lbs gain throughout the middle from about 3600-6200 rpm That is pretty amazing for a normally aspirated motor. You can also see the validity for the conditions of the second plot as it starts and finishes in the exact place for the beginning and then the ending of each run. Of course plot three is just plain better everywhere!
A 2014 3.4 L Cayman S in stock form, then headers added alone, and then a protune added by Cobb themselves to maximize the performance of the car with the Cargraphics headers. Final crank numbers are estimated at 367 hp and 314 tq. Not bad for a header and tune.
Which headers did you go with? No air filter upgrades?
I've got K&N filters right now with a COBB AP and Fabspeed race headers on the way. Curious to see if the numbers I get with one of the off the shelf flashes comes close.
Hi lovetoturn,
I looked up the original numbers for a 2014 CM S; 325 HP, 273 TQ. So it looks like the upgrades only got you back to original numbers. Are the chart numbers wheel HP, maybe? The numbers I'm quoting above are from Porsche in an article when the 2014 was released, so maybe those are engine HP and TQ.
The question above aside, that's an impressive chart!
Joe Henley
Hi lovetoturn,
I looked up the original numbers for a 2014 CM S; 325 HP, 273 TQ. So it looks like the upgrades only got you back to original numbers. Are the chart numbers wheel HP, maybe? The numbers I'm quoting above are from Porsche in an article when the 2014 was released, so maybe those are engine HP and TQ.
The question above aside, that's an impressive chart!
Joe Henley
Hey Joe,
He is at 367 hp and 316 tq when comparing to stock numbers 325/273. These are crank hp numbers. The dyno chart shows wheel hp.
Mike is correct. The dyno is wheel horsepower and this has to be be converted back to crank horsepower. Notice how the stock car's dyno numbers are significantly lower than the stated crank numbers from Porsche. This car is only headers and tune. No PSE, stock filters, and no plenum. Plenum and TB don't seem to do much for these cars as compared to the GT4s.
L2T,
Ah, I missed the "Final crank numbers are estimated at 367 hp and 314 tq." sentence in your original post. Thanks for you and Mike pointing that out.
How do you convert between crank and wheel HP/TQ? Is it a fixed percentage?
Joe Henley
A few ways to do that, but the easiest one is to take a ration of the OEM crank rated hp and TQ numbers and compare them to the new numbers after any modifications are complete. In this case you take Porsche's OEM stock rating of 325 hp and divide by the dyno rating of 265 hp which yields a ratio of 1.2264. You then just multiply that by the dyno number of the modified car or in this case 299 hp which yields your 367 hp. Others would argue to just add the difference between the two numbers of 299-265=34 and call it a total on them modified car of 325+34 or 359 hp. They say that the driveline losses are the same, but I would argue that the driveline losses go up with increased power so I think the first number of 367 is in reality more accurate. At any rate both numbers are very close to each other and who exactly knows what you got from the factory and how well your motor is broken in. For the torque rating 273/234 x 269 = 314 ft/lbs.
"Do headers really loose that much power around 2500 rpm? According to this dyno chart it's about 30 ft/lb and 25 hp."
Is what happens at 2500 rpm really important? Who drives at 2500 rpm for more than a fraction of a second when speed is the goal? If speed isn't the goal, who cares what happens at 2500 rpm?
Well guys, there are no assumptions here, just before and after and after again dyno plots. A 2014 3.4 L Cayman S in stock form, then headers added alone, and then a protune added by Cobb themselves to maximize the performance of the car with the Cargraphics headers. Porsche penalizes the Cayman S by 25 horsepower as compared to the 911 with the same motor. This set up gets that back and an additional 17 horsepower more, along with massive gains in the torque ALL across the rev range. Final crank numbers are estimated at 367 hp and 314 tq. Not bad for a header and tune. As you can see, the headers alone make all of their power from 1800 to 5800 without any software manipulations. Porsche's ECU limits torque and no gains are seen up top until adjusted by a tune. At 3700 rpm as seen in Cobb's dyno database this set up has a peak increase in torque of 50 ft/lbs. There is about a 30ft/lbs gain in tq at each end of the dyno plot and a solid 40+ ft/lbs gain throughout the middle from about 3600-6200 rpm That is pretty amazing for a normally aspirated motor. You can also see the validity for the conditions of the second plot as it starts and finishes in the exact place for the beginning and then the ending of each run. Of course plot three is just plain better everywhere!
Lovetoturn, any reason you didn't go with the Stage 2 93 map before the Protune? I asked Cobb which to use on my 981 BS with Cargraphic Sport and PSE (no other mods), and they said to use Stage 2. I have 93 octane here in Tejas.
06-10-2018, 08:15 PM
