991.2 Dyno Day Results (C2, CT GIAC, CT Cobb, C2S X51)
 

Was able to coordinate a dyno day with some 991.2s today. We were able to test 4 911.2s with different setups:

- 2017 C2 Base: Stock tune, Fabspeed X-Pipe
- 2018 Carrera T: GIAC Tune, Full-Kline exhaust w/headers and 200 cell cats
- 2018 Carrera T: Cobb Stage 1 93 tune, Akrapovich slip-on exhaust
- 2017 Carrera S ERE: X51 Powerkit, cat-bypass

Was a mustang dyno and no correction factor was applied to the graphs. All pulls were done in 4th gear.

First graph has my stock results, GIAC results, and Cobb Stage 1 results.
Couple things to note:
- GIAC and Stock car both experience torque limiting early, while Cobb car doesn't.
- Cobb car has a stronger tune compared to the GIAC in terms of torque and power across the band.

Stock C2 - 337whp, 322 lb/ft wtq
GIAC Carrera T - 393whp, 398 lb/ft wtq
Cobb Carrera T - 404whp, 450 lb/ft wtq

https://cimg1.ibsrv.net/gimg/rennlis...b4af587fd8.jpg




Below is graph with Cobb, GIAC, and X51 Powerkit data:

C2S X51 - 409whp, 398 lb/ft wtq
GIAC Carrera T - 393whp, 398 lb/ft wtq
Cobb Carrera T - 404whp, 450 lb/ft wtq

Note that the GIAC and X51 graphs looks very similar in terms of structure. Nearly mimic movement...

https://cimg1.ibsrv.net/gimg/rennlis...a56ebf1ff2.jpg



Interesting to see how the tunes perform. GIAC seems to mimic OEM performance, while Cobb is a bit more aggressive with the power delivery. Overall, solid day at the dyno shop. Catless sounds very nice! I think I know my next mod...

Special thanks to Rennolazine (CT GIAC), PCA1983 (C2S X51), and Kiril (CT Cobb) for making it to the shop!
Thanks to APM Performance for accommodating us for the dyno pulls.

Rennolazine made a video documenting the day:



https://cimg4.ibsrv.net/gimg/rennlis...90633ffca5.jpg

Here's my graph (Stock C2)
https://cimg1.ibsrv.net/gimg/rennlis...ffca787ae9.jpg


Here's the C2S X51 Graph:
https://cimg0.ibsrv.net/gimg/rennlis...3f2d5248e8.jpg

For reference here is the Hydra tune.
https://cimg0.ibsrv.net/gimg/rennlis...ac5aba44c8.png
https://cimg3.ibsrv.net/gimg/rennlis...3eb9a09ef2.png

Even though dynojet are more generous than mustang the baseline doesnt seem too far off. The gains are massive! Have you had any limp modes or transmission error codes on the dyno or on the street?

I just did the Cobb stage 1 tune to my 19 c4s and the thing RIPS. This was before the high flow cats too. The Cobb tune just brings a surge of boost wayyyy earlier feel wise. Spool happens so much quicker it's crazy...I'm not normally a tuner, but these things get up to turbo speed with under 2k worth of work which is pretty nuts on the value scale, not to mention the Carrera types are a good 300 lbs lighter than the turbo platform...

Zero issues... and I mean zero. Car runs as stock but pulls like a freight train!! Driveablity is so much better than any other tune I've ever had. Which is to say it feels stock.

How is that even possible since the 991.2 cars don't have any turbo lag? (being sarcastic)

I'm jealous. Just got done with a bolt on build of my 987 and spend a lot of money for a laughable increase in power by the numbers.

In sport plus the turbos are prespooled to ver 2psi with my tune.

Yesterday was fun. I thought the numbers should have been a bit higher, but from what I read, that is the effect of the Mustang dyno. Its hard to find an exact number but from what I read, some folks seem to think the Mustang dyno reads about 7% low. Is that a reasonable estimate???

Hi steve the shop estimates their numbers (uncorrected) are roughly 10% lower than an uncorrected dynojet and up to 20% lower than crank hp. I think its probably what youre saying (maybe 7%). If you compare Aatish’s numbers to the hydra dynojet numbers for the base the difference is about 5%. Even at a VERY conservative 15% drivetrain loss your car is at 470 crank hp and 455 crank tq. Its probably more than that

Correction factor to stock on C2 Base is .911, too funny.

rosenbergendoI results are similar to my Hydra tune

The GIAC tune is quite tame. That car had headers and high flow cat, so two big exhaust restrictions removed, yet didn't make near the torque of the COBB tuned car without headers or HFCs. I suppose that's why GIAC is a dealer installed option and the COBB is not.

Uncorrected Dyno numbers will be all over the place based on temp, humidity, dew point, baro press, etc. Corrected numbers are easier to compare later down the road.

Those are good numbers for a Mustang Dyno I think