991.2 C2S Boost Pressure
04-17-2017, 09:35 AM
#31
Burning Brakes
When I took delivery of my Targa 4S @ PEC they provided my with a Targa 4S with 100 miles on the odometer to drive on the track. It made full boost.
04-17-2017, 09:36 AM
#32
Rennlist Member
Thread Starter
Had my Targa 4S out yesterday and was able to do some testing for you. I am closer to your location/conditions as I am in southern CT near NYC ~200 ft above sea level temps were between 75-89*
Manual transmission so I don't have sport response but I was in Sport Plus.
2nd gear and 3rd gear easily saw 16psi with several quick spikes to 17psi.
Would see 16psi from 5000-7000rpm.
I need to do more testing but I don't recall seeing above 15psi in Sport mode.
I believe the spikes to 17psi were due to my Fabspeed headers and sport cats.
(EDIT: nope guess 17psi is normal:
https://rennlist.com/forums/991/9858...l#post14116512)
Not sure if this helps but I set my boost gauge to be at the top of the LCD cluster. I believe this is the default location for fuel range and is curved (not a straight line like default boost or oil pressure is lower in the gauge).
So the next question is what mode are you testing your car in?
If you haven't been using Sport Plus then maybe this will solve your issue.
Manual transmission so I don't have sport response but I was in Sport Plus.
2nd gear and 3rd gear easily saw 16psi with several quick spikes to 17psi.
Would see 16psi from 5000-7000rpm.
I need to do more testing but I don't recall seeing above 15psi in Sport mode.
I believe the spikes to 17psi were due to my Fabspeed headers and sport cats.
(EDIT: nope guess 17psi is normal:
https://rennlist.com/forums/991/9858...l#post14116512)
Not sure if this helps but I set my boost gauge to be at the top of the LCD cluster. I believe this is the default location for fuel range and is curved (not a straight line like default boost or oil pressure is lower in the gauge).
So the next question is what mode are you testing your car in?
If you haven't been using Sport Plus then maybe this will solve your issue.
I am not aware of a sport plus mode for my car, I have normal, and sport.... I will do more fiddling around when I get into the car today and see if I am missing something.
** Just read the manual, the dial selector on the steering wheel is for cars with Sport Chrono which my car does not have.
04-17-2017, 09:38 AM
#33
Rennlist Member
Thread Starter
OP, How many miles do you have on the car?I just bought a new C2S and my dealer told me Porsche limits boost until the car reaches 1200 miles. Not sure by how much, but it's a thought. My car has only 500 miles so far so I'm going a little easy yet. Not pushing the boost at all yet.
Alec
Alec
04-17-2017, 09:47 AM
#34
max 17.4psi
see here, relative to throttle response - real data and real telemetry
https://rennlist.com/forums/991/9858...carrera-s.html
see here, relative to throttle response - real data and real telemetry
https://rennlist.com/forums/991/9858...carrera-s.html
04-17-2017, 03:02 PM
#35
Rennlist Member
Your logic and explanation make perfect sense, but I'm in the Denver area with my 991.2 Carrera and have never seen more than the nominal 13 psi boost. Not even when charging hard on Squaw Pass road on the way to Mt. Evans and hitting triple digit speeds. That road peaks at a bit over 11,000 feet.
04-17-2017, 06:17 PM
#36
thanks- Good luck-
alec
04-17-2017, 07:51 PM
#37
Burning Brakes
I own a 991.2. I've had full boost the entire time. I'm only just at ~1200 miles as of this weekend. I drove it home from PEC in ATL to CT in December...
Do you even own one?
Do you even own one?
Last edited by Jenner; 04-18-2017 at 08:31 AM.
04-17-2017, 11:55 PM
#38
04-18-2017, 08:30 AM
#39
Burning Brakes
06-25-2017, 02:29 PM
#40
Rennlist Member
Just reviving this thread. I have a manual 991.2 c2s that's a manual and I'm having the same concerns as the op. I can't get boost levels above 12/13 max before the blow off valve releases even at full throttle it just releases and stays at 12/13. I can just hear it releasing behind me. Is this normal?
06-25-2017, 08:35 PM
#41
Instructor
My 991.2 C2S has about 750 miles, and I have done a few 2nd gear pulls pedal to the floor keeping the speeds street legal (and under 5500rpm), and I haven't seen 16psi as the OP. I've seen 10-13psi max before I backed off.
I'm doing a track day in about a month or so, so I'll probably break 1,000 mi by then, I'll report back when I see the described limits.
Interesting that I noticed that the first time, but thought I just wasn't pushing enough (nor would I want to
, this thing is too fast the for the street).
I'm doing a track day in about a month or so, so I'll probably break 1,000 mi by then, I'll report back when I see the described limits.
Interesting that I noticed that the first time, but thought I just wasn't pushing enough (nor would I want to
, this thing is too fast the for the street).
06-26-2017, 10:44 PM
#42
Rennlist Member
Can you hear the valve releasing air and pressure once you hit 13? I can. It's maxed out to rebuild boost I have to let off and let the vacuum build pressure back up
06-27-2017, 12:18 AM
#44
Rennlist Member
06-27-2017, 01:37 AM
#45
Rennlist Member
My TT shows a peak of 19 psi on a 7400 ft density altitude day.
https://airdensityonline.com/tracks/
Porsche reports 1.0 bar + 0.15 bar overboost. 1.15 bar = 16.7 psi.
Since 14.7 psi is the baseline and at the 7400 ft density altitude we only have 80% of the air (80% of 14.7 = 11.8), I am down by 14.7 - 11.8 = 2.9 psi. The car boost reading is rounded to the nearest 1 psi so it's either fully adjusting for altitude or quite nearly so.
https://airdensityonline.com/tracks/
Porsche reports 1.0 bar + 0.15 bar overboost. 1.15 bar = 16.7 psi.
Since 14.7 psi is the baseline and at the 7400 ft density altitude we only have 80% of the air (80% of 14.7 = 11.8), I am down by 14.7 - 11.8 = 2.9 psi. The car boost reading is rounded to the nearest 1 psi so it's either fully adjusting for altitude or quite nearly so.