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WinRice WinRice is offline
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Join Date: Jun 2005
Location: Colorado
Posts: 700
Originally Posted by aerochip View Post
This is very enlightening. My understanding of turbocharging and waste gates at altitude was incorrect. What I now understand is that the waste gate opens at 1 Atmosphere + what the waste gate spring is set at. At 7,000', 1 Atmosphere = .797 bar per the chart. Add the altitude adjusted atmosphere of .8 to the .8 bar spring and you have 1.6bar. The waste gate sees this as max boost; which is indicated as .6 bar on the gauge.
You have to be careful because it depends on how the gage is calibrated.

0 at sea level it reads 0.6 bar
0 at 7000 ft it reads 0.8 bar

Assuming your numbers above.

My Zeitronix system calibrates to 0 everytime I turn the key on. Which is fine if I stay at one altitude. Not accurate if I travel down to Denver or up to the mountains without a restart.
1986 911 Turbo
3.3L, K27HFS, Tial 46mm, TurboKraft Intercooler, 964 Cams, Monty Muffler, MS3Pro Evo, M&W Ignition, Zietronix WBO2 Data Logger, Wevo shifter, coupler and motor mounts.
Old 05-30-2014, 05:29 PM
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