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Boost levels and Atmospheric Conditions thread

24K views 59 replies 19 participants last post by  Flash's Owner 
#1 ·
Hey all fellow Solstice GXP and SKY RL owners with the LNF engine!

I would like to start keeping track of some boost information and see if I can correlate DIC boost levels with atmospheric conditions.

To get to that, I need to acquire data from as many of us that are willing to participate. Here is what I would propose:

- We use a standard procedure, simple in nature, to note the maximum DIC boost level.

- Simply run the procedure, note the local date and time, and the nearest airport.

Post the information here in the following format:

Boost level sustained:
Peak boost noted if different than the sustained level:
Date and time:
Nearest airport: (you can also note the city and state, or find nearest ASOS/AWOS via AirNav)
Performance Modifications: (stock, exhaust/intake, stage kit or tune, etc.)

It is that simple. I can calculate the rest from there. I plan on trying to plot the boost pressure and density altitude to see if I can tell what is normal and what different modifications mean.




The procedure:
-Make sure your car is warm. DIC coolant temperature should be >185ºF
-Set your DIC to monitor boost. Be sure to wait until the display is active (displaying the PSI, not "BOOST" when the gage is initiating)
-Start the procedure in 3rd gear at 30-35 MPH (approximately 2000-2500 RPM)
-Go to Wide Open Throttle (WOT)
-Note the sustained and peak values you see on your DIC. Accelerate to as high a speed as you are comfortable.
-watch out for deer, pedestrians, other cars and curves. Maintain control of your car at all times, and obey traffic laws where applicable. :)
-Note the date and time.


Keep in mind that you may see a traction light, so you may want to do this in competitive mode to avoid this happening. If the traction control becomes active, you will lose your boost gage to the superceding traction control message.


For example, on the way in on the morning of 2/17/09:

Boost level sustained: 22
Peak boost level: same (22PSI, solid)
Date and Time: 2009.02.17 06:53 EST
Nearest Airport: Howell or Pontiac (KOZW or KPTK, Milford Proving Ground is 1/2 way between)
Performance Modifications: GM PUpgrade Kit, 6 shortening wastegate turns from stock, stock intake/exhaust

From that, we can determine the weather conditions and calculate the density altitude is -1456' for this run.


I am especially interested in stock vehicles. I think a typical LNF car is not going to be too far away from this:

-2000' (cold day below freezing) 14-15 PSI
-1000' (15-16)
0' (16-17)
+1000' (17~18)
+2000' 19 PSI (close to SAE J1349 standard)
+4000' 20 PSI
+6000' 20~21 PSI
 
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#30 ·
Boost level sustained: 23psi
Peak boost level: 23psi
Date and Time: 4/10/2009 3:00 PM EST
Nearest Airport: Newark Airport EWR
Performance Modifications: GMPP Turbo Performance Upgrade Kit

This is on the way home after having it installed, unfortunately I forgot to turn stability control or go into competition mode.

I was able to get 21psi sustained in 4th gear, and 23psi sustained in 5th gear
 
#31 ·
Flash's Owner,

Just want to thank you for doing this for us (me). It helped me feel better about the lower numbers I was seeing (knowing that it's not a problem and that the results are expected based on elevation and other factors).

I'm about to get the performance upgrade, so will post new info when I get it.

Thanks Again...
 
#32 ·
kennysabarese

Boost level sustained: 23psi
Peak boost level: 23psi
Date and Time: 4/10/2009 3:00 PM EST
Nearest Airport: Newark Airport EWR
Performance Modifications: GMPP Turbo Performance Upgrade Kit


METAR KEWR 101851Z 15007KT 110V180 10SM OVC085 14/01 A3001 RMK AO2 SLP160 T01440011
Elevation: 18'

Density Altitude -114.2 ft

Absolute Pressure (station pressure) 29.99 in Hg

Relative Density (ISA) 100.33%
Actual Density (kg/m^3) 1.2291
Relative Humidity Relative Humidity = 41%

23PSI (DIC) = 37.7 PSI abs / 2.601 bar
 
#33 ·
I’m maxing my little turbo out up here.

4700’ ASL

3rd Gear Pull
Initial 23 PSI Spike tapering off to 18 PSI at 6,500 RPMS.

4th Gear Pull

Initial 23 PSI Spike tapering off to 20 PSI at 6500 RPMs

Freeway Roll with Competitive Setting.
 
#35 ·
bradyb, I need your location or the nearest airport and date and time, in order to calculate your density altitude.



elff:
Boost level sustained: 21psi
Peak boost level: 21psi
Date and Time: 4/9/2009 3:00 PM EST
Nearest Airport: Philadelphia PA
Performance Modifications: GMPP Turbo Performance Upgrade Kit, Dejon CAI, Dejon Intercooler Pipes

METAR KPHL 091854Z 24014KT 10SM FEW075 17/M06 A2984 RMK AO2 SLP106 T01671061
Elevation 36'

Density Altitude 423.2 ft

Absolute Pressure (station pressure) 29.801 in Hg

Relative Density (ISA) 98.77%
Actual Density (kg/m^3) 1.2099
Relative Humidity Relative Humidity = 20%


21PSI (DIC) = 35.6 PSI abs / 2.457 bar
 
#34 ·
Boost level sustained: 21psi
Peak boost level: 21psi
Date and Time: 4/9/2009 3:00 PM EST
Nearest Airport: Philadelphia PA
Performance Modifications: GMPP Turbo Performance Upgrade Kit, Dejon CAI, Dejon Intercooler Pipes

I wasn't trying all that hard.
Previously, before the Dejon equipment, I had hit 23psi.
 
#36 ·
I already saved you the time, 4700' ASL. SLC 14:00 4/11/09
 
#38 ·
Boost level sustained: 19-20psi
Peak boost noted if different than the sustained level: 20psi
Date and time: 4/18/2009 : 9:30am EDT
Nearest airport: Phillips Army Airfield KAPG
Performance Modifications: GMPP Stage II kit, K&N Air Filter
This is a 5-speed manual

Almost can say 20psi was sustained, it was more than a "flash"

FYI, my dashhawk 0-60 time was 5.43, down a little from my pre-GMPP best time of 5.49 I did not try too many runs.

However, now I am losing a little bit of traction in the 1-2 gear shift, and prior to the GMPP upgrade, that did not happen, for me anyway. Think I still have some learning to do to get that time down some more. I know dashhawk times are not that reliable, but the on the same car for the same strip of road for the same driver, they are a fun comparison.
 
#39 ·
Boost level sustained: 20psi
Peak boost level: 21
Date and Time: 4/17/2009 3:00 PM gmt-7
Nearest Airport: lake havasu city airport AZ
Performance Modifications: see sig

i had lost preasure the day before went to 12. i checked the hose at the TB it was about ready to fall off, tightened clamp. now i get 21 peak in 1-4. have not went that far in 5. since i checked the hose it now gets 21 peak was 20 so it may have been the leak
 
#40 ·
i had lost preasure the day before went to 12. i checked the hose at the TB it was about ready to fall off, tightened clamp. now i get 21 peak in 1-4. have not went that far in 5. since i checked the hose it now gets 21 peak was 20 so it may have been the leak
I've read about that so much, it resulted in me throwing a little more money at Dejon. I really think their elbow is the permanent solution. It replaces that rubber hose and all the clamps are T-Bolts :thumbs:
 
#41 ·
BRADYB:

I’m maxing my little turbo out up here.

4700’ ASL

3rd Gear Pull
Initial 23 PSI Spike tapering off to 18 PSI at 6,500 RPMS.

4th Gear Pull

Initial 23 PSI Spike tapering off to 20 PSI at 6500 RPMs

Freeway Roll with Competitive Setting.

I already saved you the time, 4700' ASL. SLC 14:00 4/11/09


METAR KSLC 111953Z 00000KT 10SM FEW045 SCT070 SCT100 OVC140 12/01 A2977 RMK AO2 SLP059 T01220011
Altitude 4227'

Density Altitude 4894.9 ft

Absolute Pressure (station pressure) 25.668 in Hg

Relative Density (ISA) 86.44%
Actual Density (kg/m^3) 1.0589
Relative Humidity Relative Humidity = 47%

23PSI (DIC) = 35.6 PSI abs / 2.455 bar
20PSI (DIC) = 32.6 PSI abs / 2.248 bar
18PSI (DIC) = 30.6 PSI abs / 2.11 bar
======================================================

mimeauja:

These are my new numbers with the performance tune! awesome!

Boost level sustained: 17
Peak boost level: 18
Date and Time: 4/16/2009 5:45 PM EST
Nearest Airport: Westover Air Force Base (Chicopee, MA)
Performance Modifications: GMPP Performance Upgrade

METAR KCEF 162155Z 00000KT 10SM CLR 17/M09 A3022 RMK AO2A SLP237 T01671086
Elevation 241'

Density Altitude 233.4 ft

Absolute Pressure (station pressure) 29.958 in Hg

Relative Density (ISA) 99.32%
Actual Density (kg/m^3) 1.2167
Relative Humidity Relative Humidity = 16%

17PSI (DIC) = 31.7 PSI abs / 2.187 bar
18PSI (DIC) = 32.7 PSI abs / 2.256 bar

give it some time to learn a bit, then try again. I bet you will pick up another PSI or two.

==========================================================

sunnygator:

Boost level sustained: 19-20psi
Peak boost noted if different than the sustained level: 20psi
Date and time: 4/18/2009 : 9:30am EDT
Nearest airport: Phillips Army Airfield KAPG
Performance Modifications: GMPP Stage II kit, K&N Air Filter
This is a 5-speed manual

Maryland Science Center closest weather:
METAR KDMH 181254Z AUTO 18/M05 A3012 RMK AO2 SLP199 T01781050 PWINO TSNO
METAR KDMH 181354Z AUTO 19/M04 A3012 RMK AO2 SLP200 T01941039 PWINO TSNO
Elevation: Approx 40' (ranges 20 to 50')

Density Altitude 291 ft

Absolute Pressure (station pressure) 30.077 in Hg

Relative Density (ISA) 99.15%
Actual Density (kg/m^3) 1.2146
Relative Humidity Relative Humidity = 21%

19PSI (DIC) = 33.8 PSI abs / 2.329 bar
20PSI (DIC) = 34.8 PSI abs / 2.397 bar

================================================================

MAC

Boost level sustained: 20psi
Peak boost level: 21
Date and Time: 4/17/2009 3:00 PM gmt-7
Nearest Airport: lake havasu city airport AZ
Performance Modifications: see sig
2008 GXP
Auto
Air
Mud Gaurds
GMPP Tune
Solo Mach Shorty
Solo CAT
Norms T skirts



METAR KEED 172156Z AUTO 05008G21KT 020V090 10SM CLR 26/M03 A3002 RMK AO2 SLP146 T02561028
Elevation 983' (at KEED, needles, closest ASOS)


Density Altitude 2428.8 ft

Absolute Pressure (station pressure) 28.969 in Hg

Relative Density (ISA) 93.08%
Actual Density (kg/m^3) 1.1403
Relative Humidity Relative Humidity = 15%

20PSI (DIC) = 34.2 PSI abs / 2.36 bar
21PSI (DIC) = 35.2 PSI abs / 2.429 bar

================================================================
Another recent run for FLASH:

Boost level sustained: 23
Peak boost level: 24
Date and Time: 2009.04.17 3:00 PM KPTK
Nearest Airport: Howell or Pontiac (KOZW or KPTK, Milford Proving Ground is 1/2 way between), using KPTK
Performance Modifications: GM PUpgrade Kit, 6 shortening wastegate turns from stock, stock intake/exhaust, top down :D


KPTK 171953Z 28010KT 10SM CLR 21/M03 A3029 RMK AO2 SLP261 T02061028
Altitude: 1000'

Density Altitude 1577.3 ft

Absolute Pressure (station pressure) 29.214 in Hg

Relative Density (ISA) 95.46%
Actual Density (kg/m^3) 1.1694
Relative Humidity Relative Humidity = 20%

23PSI (DIC) = 37.3 PSI abs / 2.575 bar
24PSI (DIC) = 38.3 PSI abs / 2.644 bar
 
#42 ·
Very Interesting Flash Man, thanks for the numbers.
You're running the GM Tune with the waste gate screws turned?

Just as an FYI, yesterday it was 73 degrees on the way home. At 6500 RPMS I was getting 17 PSI in 3rd and 18 PSI in 4th. I want a bigger turbo that can handle my alttitude. I don't want to worry about running Methanol but it sure would be slick to run 22-23 PSI all the way to 7,000 RPMS.
 
#43 ·
Flash's Owner, thanks for doing this and all the other GM PUpgrade work you have done in the past.

My stats:
Boost level sustained: 140 kPa (20.3 psi) 3rd and 4th gear. Note 100 kPa sustained previously in stock condition.
Peak boost level: 140 kPa (20.3 psi)
Date and Time: 4/21/2009 13:00 EST
Nearest Airport: Hamilton International Airport, Ontario, Canada
Performance Modifications: GM Performacne Upgrade Kit, Solo Free-Flow CAT, Solo Mach Shorty, Wastegate adjusted 2 turns, T-Bolt clamps on TB hose at TB and Duct end.
 
#44 ·
Topdowneh:

My stats:
Boost level sustained: 140 kPa (20.3 psi) 3rd and 4th gear. Note 100 kPa sustained previously in stock condition.
Peak boost level: 140 kPa (20.3 psi)
Date and Time: 4/21/2009 13:00 EST
Nearest Airport: Hamilton International Airport, Ontario, Canada
Performance Modifications: GM Performacne Upgrade Kit, Solo Free-Flow CAT, Solo Mach Shorty, Wastegate adjusted 2 turns, T-Bolt clamps on TB hose at TB and Duct end.


METAR CYHM 211700Z 20018KT 15SM -SHRA FEW024 BKN031 OVC042 09/04 A2962 RMK CU2SC5SC2 SLP033
Elevation 780'

Density Altitude 700.6 ft

Absolute Pressure (station pressure) 28.793 in Hg

Relative Density (ISA) 97.97%
Actual Density (kg/m^3) 1.2001
Relative Humidity Relative Humidity = 71%

20.3PSI (DIC) = 34.4 PSI abs / 2.375 bar
 
#45 ·
Hey Flash Man, get Rob the Elder's numbers. He's up at 8,000 ASL and he's saying he can pull 23 PSI through third.
 
#47 ·
I was playing around with my Driver Information Center, and discovered that you can change your boost gage display to kPa. The increment is in 5 kPa, so a change of 5 kPa on your gage is 0.725 PSI.

This is interesting to me because several days ago I was running in a higher density altitude day (warm and high humidity, nearly 2800' DA), but getting similar pressures as when I was running my car around 1400' DA. My calculated boost pressure was lower but my car still felt just as strong.

It turns out that you can use both the metric and the english measurements to get at a slightly improved discretion for your boost pressure.

I worked it out to approximately 1/3 PSI discretion. They way I do it is run a run or two in metric, then run a run or two in english. I have been able to distinguish between 23.6 and 24.3 PSI on two days, even though my gage only read 24 PSI.


Here is a lookup table for those interested:

DIC of 70 kPa and 10 PSI is [ 10.1 PSI ]
DIC of 75 kPa and 10 PSI is [ 10.4 PSI ]
DIC of 70 kPa and 11 PSI is [ 10.6 PSI ]
DIC of 75 kPa and 11 PSI is [ 10.9 PSI ]
DIC of 80 kPa and 11 PSI is [ 11.3 PSI ]
DIC of 80 kPa and 12 PSI is [ 11.8 PSI ]
DIC of 85 kPa and 12 PSI is [ 12.2 PSI ]
DIC of 85 kPa and 13 PSI is [ 12.7 PSI ]
DIC of 90 kPa and 13 PSI is [ 13 PSI ]
DIC of 95 kPa and 13 PSI is [ 13.4 PSI ]
DIC of 90 kPa and 14 PSI is [ 13.5 PSI ]
DIC of 95 kPa and 14 PSI is [ 13.9 PSI ]
DIC of 100 kPa and 14 PSI is [ 14.3 PSI ]
DIC of 100 kPa and 15 PSI is [ 14.8 PSI ]
DIC of 105 kPa and 15 PSI is [ 15.1 PSI ]
DIC of 110 kPa and 15 PSI is [ 15.5 PSI ]
DIC of 105 kPa and 16 PSI is [ 15.6 PSI ]
DIC of 110 kPa and 16 PSI is [ 16 PSI ]
DIC of 115 kPa and 16 PSI is [ 16.3 PSI ]
DIC of 115 kPa and 17 PSI is [ 16.8 PSI ]
DIC of 120 kPa and 17 PSI is [ 17.2 PSI ]
DIC of 120 kPa and 18 PSI is [ 17.7 PSI ]
DIC of 125 kPa and 18 PSI is [ 18.1 PSI ]
DIC of 130 kPa and 18 PSI is [ 18.4 PSI ]
DIC of 125 kPa and 19 PSI is [ 18.6 PSI ]
DIC of 130 kPa and 19 PSI is [ 18.9 PSI ]
DIC of 135 kPa and 19 PSI is [ 19.3 PSI ]
DIC of 135 kPa and 20 PSI is [ 19.8 PSI ]
DIC of 140 kPa and 20 PSI is [ 20.2 PSI ]
DIC of 140 kPa and 21 PSI is [ 20.7 PSI ]
DIC of 145 kPa and 21 PSI is [ 21 PSI ]
DIC of 150 kPa and 21 PSI is [ 21.4 PSI ]
DIC of 150 kPa and 22 PSI is [ 21.9 PSI ]
DIC of 155 kPa and 22 PSI is [ 22.2 PSI ]
DIC of 155 kPa and 23 PSI is [ 22.7 PSI ]
DIC of 160 kPa and 23 PSI is [ 23.1 PSI ]
DIC of 160 kPa and 24 PSI is [ 23.6 PSI ]
DIC of 165 kPa and 24 PSI is [ 24 PSI ]
DIC of 170 kPa and 24 PSI is [ 24.3 PSI ]
DIC of 170 kPa and 25 PSI is [ 24.8 PSI ]
DIC of 175 kPa and 25 PSI is [ 25.2 PSI ]
DIC of 175 kPa and 26 PSI is [ 25.7 PSI ]
DIC of 180 kPa and 26 PSI is [ 26.1 PSI ]
DIC of 185 kPa and 26 PSI is [ 26.4 PSI ]
DIC of 180 kPa and 27 PSI is [ 26.6 PSI ]
DIC of 185 kPa and 27 PSI is [ 26.9 PSI ]
DIC of 190 kPa and 27 PSI is [ 27.3 PSI ]
DIC of 190 kPa and 28 PSI is [ 27.8 PSI ]
DIC of 195 kPa and 28 PSI is [ 28.1 PSI ]
DIC of 195 kPa and 29 PSI is [ 28.6 PSI ]
DIC of 200 kPa and 29 PSI is [ 29 PSI ]
DIC of 200 kPa and 30 PSI is [ 29.5 PSI ]


Enjoy.
 
#49 ·
12:45 PM eastern time
Airport: EWR
20PSI boost in 4th sustained
21PSI boost in 5th sustained
Mods: GMPP Turbo Upgrade Kit

This is lower than I usually get. Maybe the weather has changed and affected it from last time?
 
#50 ·
kennysabarese

12:45 PM eastern time
Airport: EWR
20PSI boost in 4th sustained
21PSI boost in 5th sustained
Mods: GMPP Turbo Upgrade Kit

This is lower than I usually get. Maybe the weather has changed and affected it from last time?


METAR KEWR 021651Z 30007KT 10SM BKN047 BKN100 17/08 A2992 RMK AO2 SLP132 T01670078
Elevation 18'

Density Altitude 396.6 ft

Absolute Pressure (station pressure) 29.901 in Hg

Relative Density (ISA) 98.84%
Actual Density (kg/m^3) 1.2108
Relative Humidity Relative Humidity = 55%

20PSI (DIC) = 34.7 PSI abs / 2.392 bar
21PSI (DIC) = 35.7 PSI abs / 2.46 bar



According to this data, so far from what I can tell, the stock car seems to peak out around 2.0 bar, GMPP with little adjustment is around 2.3 bar.

Each 2-3 turns on the wastegate seems to add about 0.1 bar to the max boost.
 
#51 ·
Superchips Boost

08 GXP 5-speed manual

Boost level sustained: 19 psi
Date and time: 5/21/2009 8:30 P.M. EST
Nearest airport: Buttonville/Toronto
Performance Modifications: Superchips 91 Octane Tune. No other mods


Outside temp around 26 degrees C.

The DIC shows outside temps?
 
#53 ·
08 GXP 5-speed manual

Boost level sustained: 19 psi
Date and time: 5/21/2009 8:30 P.M. EST
Nearest airport: Buttonville/Toronto
Performance Modifications: Superchips 91 Octane Tune. No other mods


Outside temp around 26 degrees C.

The DIC shows outside temps?
Apparently so.

Elevation 884'
METAR CYKZ 220000Z 22009G16KT 15SM FEW270 26/08 A3004 RMK CI1 SLP169

Density Altitude 2360.4 ft

Absolute Pressure (station pressure) 29.093 in Hg

Relative Density (ISA) 93.27%
Actual Density (kg/m^3) 1.1426
Relative Humidity Relative Humidity = 32%

19PSI (DIC) = 33.3 PSI abs / 2.295 bar
 
#52 · (Edited)
According to this data, so far from what I can tell, the stock car seems to peak out around 2.0 bar, GMPP with little adjustment is around 2.3 bar.
My first time i got 23PSI (DIC) = 37.7 PSI abs / 2.601 bar

I ran again tonight after driving for 4 hours straight. Weather channel said humidity was 90% so maybe that's why i wasn't getting my normal 23 psi?

5/23/09 9:00pm eastern
EWR
07 Sky Redline Manual
Mods: GMPP Tune, Stock intake with baffles cut off
Sustained 19psi - Peak 20psi
 
#55 ·
Sorry, I guess only the Saturns show outside temps. We never got the DIC upgrade, apparently.
 
#57 ·
2009 GXP Coupe Manual
Time:1430 CDT
Altitude: 500 [I ran across the Dam, ~30' higher than the water which is at 469.7 Today]
Temp: 86
Boost DIC Peak: 25
Boost DashHawk sustained: 22.65
Mods: Minus 4 Turns
Airport: HBZ Elevation 632'

METAR KCCA 101935Z AUTO 26006KT 6SM HZ FEW075 31/24 A2983 RMK AO2
Altitude used for density altitude calc = 632'

(for clarification, just minus 4 turns on the WG? No PUpGrade kit?)

Density Altitude 3092.6 ft

Absolute Pressure (station pressure) 29.155 in Hg

Relative Density (ISA) 91.26%
Actual Density (kg/m^3) 1.1179
Relative Humidity Relative Humidity = 66%

25PSI (DIC) = 39.3 PSI abs / 2.711 bar
22.65PSI (DIC) = 37 PSI abs / 2.549 bar

Your car is acting like a Performance Upgrade Kit was installed. I cannot recall if you told me you had it installed before delivery, but if not your car is the highest damn boost I have ever seen on a stock calibration.

This is roughly what my car runs, approximately 2.6 bar, 6 shortening turns on the WG.
 
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