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I had posted the throttle blade stuff on ************ ( and on one thread here).
Is that with the COBB stage 1 tune? I have seen the throttle blade closing with the stock tune while the throttle position is 100%. I also assumed it was for torque limiting management.
Is that with the COBB stage 1 tune? I have seen the throttle blade closing with the stock tune while the throttle position is 100%. I also assumed it was for torque limiting management.
Yep, stage 1, throttle blade bounces for a couple of seconds after each gear shift ( PDK) before steadying.
Waste gate bounces in sync with the throttle blade, but at a much smaller magnitude.
The throttle moves like that as the system is trying to maintain a targeted torque value, not a boost value. So the throttle plate modulates to meet that target. It is totally normal.
The throttle moves like that as the system is trying to maintain a targeted torque value, not a boost value. So the throttle plate modulates to meet that target. It is totally normal.
-Mitch
So when the tune is modified at Cobb, is a new torque curve target set established or is the throttle held open to match the pedal?
Ok, so had the soul sport cats and ams filter added Tuesday and ran the dyno again. Takeaways - no added power (some will even argue a slight loss of just looking at peak values, but that small of difference could be attributable it simply being a different day with different ambients, etc). In any event, no real power changes.
I will I’ll tell you, however, it sounds AMAZING Wight the sport cats and I’d buy them for that alone. The exhaust note is sport is deeper, stronger and by my very unscientific ear meter test, maybe 25% louder than stock. You pick up a good bit more turbo whistle too which I personally like. In my opinion, this is how the car should have sounded out of the factory. It really is that good.
Driving impressions: again, this is how it should have been from the factory. Perfect add of power and sound. Amazing throttle response in any gear at any time.
Ps, in response to questions re Sprt Resposme button, While we ran all runs in sport plus, we tried adding the sport response button in two of the runs and it didn’t add anything. As to why, seems that’s been covered, but good to see the tests prove it out.
Thanks for sharing. I'm about to pull the trigger on the tune. I just did a catless agency power exhaust and love it. As ricer as it sounds I wish there was more bov noise
Thank you for posting all the dynos folks, its very informative. I would bet the off the shelf tunes optimize the turbo response very well, and its not surprising that theres little difference with increase air/exhaust flow. I bet a stage 2 will push it a little harder and you will realize some bennefits. Maybe Marshall can weigh in...
With respect to a stock car, i think porsche clearly left a lot on the table with the turbo/throttle mapping, especially in normal/sport mode (boost climbs like molassess). I would expect a stock car, or one with a stage 2 tune to have at least marginal gains and butt dyno changes in driving dynamics. At least it sounds good Thats still a huge win in my book!
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Ok, so had the soul sport cats and ams filter added Tuesday and ran the dyno again. Takeaways - no added power (some will even argue a slight loss of just looking at peak values, but that small of difference could be attributable it simply being a different day with different ambients, etc). In any event, no real power changes.
Any datalogs showing ignition timing and temperatures? Ambient, engine intake, oil, etc. I find it bizarre the sport cats didn't improve power.
Any datalogs showing ignition timing and temperatures? Ambient, engine intake, oil, etc. I find it bizarre the sport cats didn't improve power.
I don't find it strange at all. Now don't get upset. I will just state some facts from experience.
Fact 1. I have always gained Power going catless. (Always - but I don't want the loudness or stink on my Porsche.)
Fact 2. I have always gained power when ever fitting an Akrapovic anything. (Always at least their claimed power)
Fact 3. I have lost power fitting cheap 200 cell metallic cats. (They fouled in under 3 months on an M3. I took them off and could see it. I won't get caught out again.)
I am not pointing fingers. I am just stating three facts. So for me, I will go Akra. There is a good reason why they are so expensive. It's because they deliver every time without fail. (And they would want to for the cost.)
I always remember a sign at a tattoo parlour. it said, "Good work is not cheap, and cheap work is not good."
It would be great to see someone dyno before and after with an Akra cat.
I don't find it strange at all. Now don't get upset. I will just state some facts from experience.
Not at all and you make good points But I always like to get a more full picture. It's so easy for dyno results to get skewed. Different ambient temps, different tire pressures, different oil temps, and with the 991.2 Carrera, getting the engine intake temps consistent and under control has proved to be difficult on the dyno due to the IC and duct layout. It doesn't help that modern ECUs are so complex have so many layers of control.
Not at all and you make good points But I always like to get a more full picture. It's so easy for dyno results to get skewed. Different ambient temps, different tire pressures, different oil temps, and with the 991.2 Carrera, getting the engine intake temps consistent and under control has proved to be difficult on the dyno due to the IC and duct layout. It doesn't help that modern ECUs are so complex have so many layers of control.
This has been my contention all along; dynoing this car is not like dynoing an NA car. Any time a car is spitting out numbers with a 5% variance in output from run to run makes it almost like a crap shoot. Nevertheless this thread continues to provide some useful information based on real world testing, especially when you're providing another person's experience as to why the sport button doesn't affect dyno output! 😂
I think we can agree that the exhaust decisions should be based on sound preference and whether or not you want the smell of petrol in your car, which I love!
Thank you for posting all the dynos folks, its very informative. I would bet the off the shelf tunes optimize the turbo response very well, and its not surprising that theres little difference with increase air/exhaust flow. I bet a stage 2 will push it a little harder and you will realize some bennefits. Maybe Marshall can weigh in...
With respect to a stock car, i think porsche clearly left a lot on the table with the turbo/throttle mapping, especially in normal/sport mode (boost climbs like molassess). I would expect a stock car, or one with a stage 2 tune to have at least marginal gains and butt dyno changes in driving dynamics. At least it sounds good Thats still a huge win in my book!
.
Agreed. I think the flow advantage will start to become evident as the boost pressures start increasing the exhaust volume.
When I swapped my stock cats out for sports, my butt dyno has me convinced there was a difference in the performance of the car. Was it as the manufacturer of these parts claimed, likely not, but I still think with all of the real time testing variances we are seeing, there is power picked there.
Agreed. I think the flow advantage will start to become evident as the boost pressures start increasing the exhaust volume.
When I swapped my stock cats out for sports, my butt dyno has me convinced there was a difference in the performance of the car. Was it as the manufacturer of these parts claimed, likely not, but I still think with all of the real time testing variances we are seeing, there is power picked there.
Agreed. Also when you increase sound, it gets the heart pumping and that can trick the butt dyno. But I think the exhaust mods will come into their own, when stage 2 and Stage 3 are released.
I have finished with my initial go around with the first batch of bolt-on power mods. The bypass pipe provided an enormous boost to low end torque at 3K RPM. Now for the track oriented goodies and 2 race track shakedowns.
The Cobb Accessport and OTS map still continue to provide the single greatest bang for the buck. Near triple digit gains at the tires for power and torque are rather ridiculous IMHO.
08-27-2018, 04:59 PM
