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A few words about the testing conditions and the intended takeaways here. I ran my car to determine the power over stock that the COBB Stg.1 tune offers. I did this to add to the community and provide some independent data. I did not do this to start an argument about max power (especially considering todays dyno conditions), dyno variance and other nonsensical topics. Lets try and keep this thread on topic and free of conjecture.
First, a big thanks to both Sam at ByDesign Auto and COBB for making this a seamless and pain free process!!
All runs were done on a Dyno Dynamics at Forged Performance in Marietta, GA. These guys are one of COBB’s authorized protuners and big in the GTR scene. Testing conditions were in Atlanta (1000ft above sea level) around +90 degrees and raining, so obviously humidity was very high, around 90%. All pulls were done in Sport (+) with 4th gear, which is slightly higher than the ideal 1:1, but the same gear all the tuners test in. The closest gear technically would be 5th, but a dyno pull with the wheel speeds of such a long gear isn’t really practical. The power pulls were done and then the car was let to cool down for about 15 mins.
Regarding 991.2 gear ratios, the base Carrera has a FDR of 3.44 in both 7MT & PDK. The remaining chassis variants have a 3.59 FDR in both 7MT & PDK.
My car is a 2017 991.2 GTS with PDK. I have a BMC filter on the car and AWE 200cell sport cats, otherwise the car is bone stock.
Now, down to my perceptions of the tune. Overall, I am very pleased with it. I have about 200 miles on it so far. The car runs solid as stock and retains the same powerband characteristics as the OEM tune. The power is very linear and pulls hard to the redline. One of my complaints with the OEM tune is the artificial feeling power plateau that would hit as the car reached around 6k rpms. That feeling is completely gone, the car just pulls hard to redline now. You can see this plateau shown on the OEM chart below in pink, it just stops climbing after 6.2k rpm. Its designed like that to limit the numbers the car makes. (What do you want to bet the 992 will have a linear chart with no plateau when Porsche modify's this tuning to give the car another 20-30rwhp?)
The powerband feels almost NA, there is no “surge-y” feeling like you encounter with large single turbo vehicles and there is ZERO lag. The turbos spool much quicker and the low rpm torque comes on like a train. I’ve found that PDK kicks up a gear early in Sport because the pedal position isn’t aggressive enough for it to hold it. I just don’t need to push the accelerator as hard as now to carry the same speed as with the stock tune. I’m assuming the COBB PDK software will help with this.
..DYNO DAY..
I had the car run 3 times with the Stg. 1 (93 oct) software loaded. The car needs time to allow the ECU to adjust to the Stg. 1 map, the only way I could practically do this would be dyno it with the COBB map loaded first and then drop to Map 0. The power pulls were within 5rwhp of each other. The highest being 470rwhp. If the weather was cooler and it wasn't as humid I think the numbers would have been a little better, but its a solid number either way.
Also playing into that number is the fact that my IAT's were 120-140F's on the power pulls, which means the car would have made considerably more power with a proper vent setup cooling the IC's and cooler ambient temps. From my logs on the hwy, I am seeing temperatures that are a good 20-30 degrees cooler on my IAT's in 4th gear.
The OEM runs, which I did 2 of, settled out at 383rwhp, but the IC’s were definitely heat soaked at that point considering they were the last runs. The first run the car was adjusting back down to the OEM tune and the numbers are off, so for simplicities sake I have excluded them. I have all the data logs for those interested. I believe that I’d probably be sitting right around the 400rwhp with a cold car, which is pretty much exactly as expected.
Overall, the car feels much more powerful. The car absolutely rips in 2nd and 3rd gear pulls starting from 3.5k. I think the Stg. 2 map should easily put the car over 500rwhp, which is a solid 100-120 rwhp over stock… not too bad! Next mod will be headers, with which I think I will probably see another 15-20rwhp consistently as well. Cat bypass pipes would also probably really help the turbos breath and prevent heat soak, but I DD the car and at the moment Im not really considering it at this moment.
To those of you who are considering tuning your car, I think COBB is hands down way to go. The support I’ve already received and the quality of their product speaks for itself.
OP, I am looking to do the Cobb time as well on my GTS
op, I want do Cobb and I want to combine with cat bypass pipes. Messaged Aaron from
Cobb and he told me that the current stage 1 time is only for stock cars with BMC or other filter upgrades. Did you have yours custom timed to account for the sport cats or just stick with the ots stage 1? Can it really matter?
OP, I am looking to do the Cobb time as well on my GTS
op, I want do Cobb and I want to combine with cat bypass pipes. Messaged Aaron from
Cobb and he told me that the current stage 1 time is only for stock cars with BMC or other filter upgrades. Did you have yours custom timed to account for the sport cats or just stick with the ots stage 1? Can it really matter?
You will always get a lawyers response from COBB. They take no responsibility for anything YOU do, nor should they. So they always advise against anything other than the order they want it released.
So whilst it is on YOU what you do, look at it with common sense. A stage 1 tune will typically Richen your A/F ratio. A cat bypass will lean out your A/F ratio. Plenty of people do Cat bypass on stock tune, and they are fine. Possibly a touch lean, but CPU would adjust.
Now Stage 1 will richen the mixture. So you tell me if it would be ok or not?
Of Course COBB won't give you the green light until they release stage 2. Which a month or so ago they said would be very soon (Around 2 weeks LOL)
They are very slow. Still waiting over a month for them to send me an empty box to ship my ECU. I have a useless COBB AP cluttering up my desk for a month. Maybe one day they will send it?
OP, I am looking to do the Cobb time as well on my GTS
op, I want do Cobb and I want to combine with cat bypass pipes. Messaged Aaron from
Cobb and he told me that the current stage 1 time is only for stock cars with BMC or other filter upgrades. Did you have yours custom timed to account for the sport cats or just stick with the ots stage 1? Can it really matter?
I have the stage 1 tune and sport cats. Seems to be working fine. The stage 2 tune will generate more power with this combo than the stage 1, but the stage 1 would work
I do suggest you ony run the 91 oct version rather than the 93 oct version to give yourself a little margin.
I have the stage 1 tune and sport cats. Seems to be working fine. The stage 2 tune will generate more power with this combo than the stage 1, but the stage 1 would work
I do suggest you ony run the 91 oct version rather than the 93 oct version to give yourself a little margin.
He would be better to just add a gallon of race fuel per full tank and he would be fine. But be your own judge. (Caveat emptor) COBB even suggest adding a 1-2 gallons if you are tracking. Its on their website.
Thx. I’ll just keep the cat bypass pipes in the box til the stage 2 comes out. Can’t wait to see how this feels. Ive had tons of 911s, mostly TT and TTS (last was a 2011 TTS) with mild tunes but thought this GTS with exhaust and tune would land me near the same power output while giving me a lighter, more agile track car. Kind of gt3 DD concept. I spend a decent amount of time at the track and tire of getting pulled down the straights by GT3RS and TTS.
You will always get a lawyers response from COBB. They take no responsibility for anything YOU do, nor should they. So they always advise against anything other than the order they want it released.
So whilst it is on YOU what you do, look at it with common sense. A stage 1 tune will typically Richen your A/F ratio. A cat bypass will lean out your A/F ratio. Plenty of people do Cat bypass on stock tune, and they are fine. Possibly a touch lean, but CPU would adjust.
Now Stage 1 will richen the mixture. So you tell me if it would be ok or not?
Of Course COBB won't give you the green light until they release stage 2. Which a month or so ago they said would be very soon (Around 2 weeks LOL)
They are very slow. Still waiting over a month for them to send me an empty box to ship my ECU. I have a useless COBB AP cluttering up my desk for a month. Maybe one day they will send it?
Can you email your info and I will get this taken care of. I am unsure how you got an AP and we didn't bench the ECU?
Hi Mitch, I made the mistake of ordering the AMS Intercoolers and asking some questions. I "ASKED" could we get it unlocked here. When we got the lawyers response that you would not even warrant the AP for any reason at all, we found that unacceptable and agreed to your lengthy, drawn out antiquated process.
I waited weeks for the empty box, however the Intercoolers and the AP showed up. When we queried this, we were told there was a communication problem and the box would be shipped ASAP. That was weeks ago. Still waiting.
I will email you now. I am not willing to go outside your process as its a cop out that you won't warrant it. So I will do EXACTLY as you say because I want warranty. That is why I have not shipped the ECU all by myself. I don't want to give you an excuse to not warrant your product. So thanks for the monthly delay. But once again, I will wait for you to send me an EMPTY box, so that I can follow your procedure and have you warrant your product that I paid for months ago.
Let's be very very clear. I DO NOT WANT ANY SPECIAL FAVOURS. I just request what I paid for. An empty box to ship you the ECU. Nothing more. Requesting any other information has already caused massive delays.
Mitch: Send this guy an empty box to send the AP back and refund his money. I have no idea how he can speak like this to people. If he spoke to me like this in person and not behind a keyboard he would learn a fast lesson.
Insult number 1: lengthy, drawn out antiquated process.
Insult number 2: I don't want to give you an excuse to not warrant your product
Insult number 3: So thanks for the monthly delay.
If you dont see a problem coming with this customer than you have to re read his post... Let him get a GIAC tune or someone else's tune and let them deal with his BS.
Mitch: Send this guy an empty box to send the AP back and refund his money. I have no idea how he can speak like this to people. If he spoke to me like this in person and not behind a keyboard he would learn a fast lesson.
Insult number 1: lengthy, drawn out antiquated process.
Insult number 2: I don't want to give you an excuse to not warrant your product
Insult number 3: So thanks for the monthly delay.
If you dont see a problem coming with this customer than you have to re read his post... Let him get a GIAC tune or someone else's tune and let them deal with his BS.
Don't put your issues on me. LOL You are the one calling companies Snake Oil salesman, not me.
I'm not calling COBB a snake oil salesman. I waited a long time for their tune to come out and its the best tune around. I couldnt be happier with the Cobb tune.
The IPD plenum, thats another story.
I'm not calling COBB a snake oil salesman. I waited a long time for their tune to come out and its the best tune around. I couldnt be happier with the Cobb tune.
The IPD plenum, thats another story.
I'm am certain their tune is the best around, I'm just impatient! Just because you are a pain in the ***, it doesn't mean, I can't be one also. : ) Takes one to know one.
Guys (I’m assuming guys based on writing style), please get a room and make up. P. Or take this transpacific hissy fit offline by pm. Or just get a beer and chill.
You are both right and you are both wrong. There, fixed.
Hi Mitch, I made the mistake of ordering the AMS Intercoolers and asking some questions. I "ASKED" could we get it unlocked here. When we got the lawyers response that you would not even warrant the AP for any reason at all, we found that unacceptable and agreed to your lengthy, drawn out antiquated process.
I waited weeks for the empty box, however the Intercoolers and the AP showed up. When we queried this, we were told there was a communication problem and the box would be shipped ASAP. That was weeks ago. Still waiting.
I will email you now. I am not willing to go outside your process as its a cop out that you won't warrant it. So I will do EXACTLY as you say because I want warranty. That is why I have not shipped the ECU all by myself. I don't want to give you an excuse to not warrant your product. So thanks for the monthly delay. But once again, I will wait for you to send me an EMPTY box, so that I can follow your procedure and have you warrant your product that I paid for months ago.
Let's be very very clear. I DO NOT WANT ANY SPECIAL FAVOURS. I just request what I paid for. An empty box to ship you the ECU. Nothing more. Requesting any other information has already caused massive delays.
Dude.. you still don't have this??
I shipped mine in by myself and insured it for 5K. I have the COBB box sitting here in my house if you want it since I didn't use it. Its literally a waterproof sleeve, some packing sheets and 2 boxes (one to go inside the other)
You could literally do this at any UPS, DHL or FedEx store. All you need from COBB is their authorization/case number so they know who's car and where its going. I would let them know whats going on also prior to shipping. Theres no way I could wait as patiently as you have!
08-04-2018, 02:10 AM
P. Or take this transpacific hissy fit offline by pm. Or just get a beer and chill.
