From d6931923f9d8414e486280909fded46073e39969 Mon Sep 17 00:00:00 2001
From: Torsten Dreyer <torsten@t3r.de>
Date: Wed, 22 Feb 2017 16:50:10 +0100
Subject: [PATCH] Fix excessive power for the 172

see:
https://github.com/c172p-team/c172p-detailed/commit/6bab47bfd0ad6a0587c1a916b863ba7181ba8543
---
 Aircraft/c172p/Nasal/c172p.nas  | 2 +-
 Aircraft/c172p/Nasal/engine.nas | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Aircraft/c172p/Nasal/c172p.nas b/Aircraft/c172p/Nasal/c172p.nas
index 43619eae5..ffcdce6c1 100644
--- a/Aircraft/c172p/Nasal/c172p.nas
+++ b/Aircraft/c172p/Nasal/c172p.nas
@@ -72,7 +72,7 @@ var autostart = func (msg=1) {
     # removing any ice from the carburetor
     setprop("/engines/active-engine/carb_ice", 0.0);
     setprop("/engines/active-engine/carb_icing_rate", 0.0);
-    setprop("/engines/active-engine/volumetric-efficiency-factor", 1.0);
+    setprop("/engines/active-engine/volumetric-efficiency-factor", 0.85);
 
     # Checking for minimal fuel level
     var fuel_level_left  = getprop("/consumables/fuel/tank[0]/level-norm");
diff --git a/Aircraft/c172p/Nasal/engine.nas b/Aircraft/c172p/Nasal/engine.nas
index 8921f837b..1cd59af71 100644
--- a/Aircraft/c172p/Nasal/engine.nas
+++ b/Aircraft/c172p/Nasal/engine.nas
@@ -180,7 +180,7 @@ var carb_icing_function = maketimer(1.0, func {
         carb_ice = std.max(0.0, std.min(carb_ice, 1.0));
 
         # this property is used to lower the RPM of the engine as ice accumulates (more ice in the carburator == less power)
-        var vol_eff_factor = 1.0 - 2.218 * carb_ice;
+        var vol_eff_factor = std.max(0.0, 0.85 - 1.72 * carb_ice);
 
         setprop("/engines/active-engine/carb_ice", carb_ice);
         setprop("/engines/active-engine/carb_icing_rate", carb_icing_rate);
@@ -191,7 +191,7 @@ var carb_icing_function = maketimer(1.0, func {
     else {
         setprop("/engines/active-engine/carb_ice", 0.0);
         setprop("/engines/active-engine/carb_icing_rate", 0.0);
-        setprop("/engines/active-engine/volumetric-efficiency-factor", 1.0);
+        setprop("/engines/active-engine/volumetric-efficiency-factor", 0.85);
         setprop("/engines/active-engine/oil_temp_factor", 0.0);
     };
 });