diff --git a/context/subsystems.md b/context/subsystems.md
index c5b2e8a..dfb5ae9 100644
--- a/context/subsystems.md
+++ b/context/subsystems.md
@@ -120,6 +120,21 @@ manual), bluish cloud screenshot-confirmed (scratchpad/flush_cloud.png). Replica
 receive @4aeef8 sets the alarm from the state stream — the port's reservoir state replication is not
 wired, so remote clouds are deferred (solo/master path complete).
 
+## Valve boost A/B/C (2026-07-23, field "boosted loop still cooked" audit) [T2 measured]
+Blackhawk, sustained BT_AUTOFIRE, 150 s soaks, `[heat-t]` 5 s cadence.  Valve shares are
+zero-sum (`valveState/Σ`); detent cycle per press = **1 → 5 → 50 → 0 (CLOSED) → 1** (@4ae464,
+one past max turns the loop OFF).  SRM6s (+ GeneratorB + Avionics) are on **Condenser2**
+([heat-link] dump; the MFD loop readout matches the heatSinkIndex truth).  Results, SRM6_1:
+- **boost 2 (share 0.91)**: plateau ~531, then COOLS under nonstop fire — never jams/fails.
+- **balanced (0.167)**: ~1162 @ 70 s and climbing (the jam band; field jams logged 1043-1469).
+- **starved (0.018)**: ~1440 @ 70 s, slope → the 2000 FailureHeat line.
+The valve mechanic is REAL and powerful; MoveValve reruns the redistribute on every press
+(not a placebo), veteran role passes the guard.  The field double-failure with "loop 2
+boosted" is therefore a DETENT question — most likely one press past max (detent 0 = closed,
+share 0) — now diagnosable: valve presses log always-on (`[valve] ... -> detent N`, with a
+CLOSED warning).  Solo clock shim verified the same day (60 s egg self-ends;
+`[mission] solo game clock expired`).
+
 ## The four systemic checks (every subsystem)
 See [[reconstruction-gotchas]]: (1) shadowing (re-declared engine-base fields), (2) the `Wword` trap,
 (3) message-handler chaining, (4) entity validity. Plus resource-struct layout (must mirror the class
diff --git a/game/reconstructed/heatfamily_reslice.cpp b/game/reconstructed/heatfamily_reslice.cpp
index 6f978c5..c0bf004 100644
--- a/game/reconstructed/heatfamily_reslice.cpp
+++ b/game/reconstructed/heatfamily_reslice.cpp
@@ -175,9 +175,14 @@ void
 		case 0:  valveState = 1;  break;		// @4ae499
 		case 1:  valveState = 5;  break;		// @4ae4a5
 		case 5:  valveState = 50; break;		// @4ae4b1 (0x32)
-		case 50: valveState = 0;  break;		// @4ae4bd
+		case 50: valveState = 0;  break;		// @4ae4bd -- one past max = CLOSED
 		default: return;						// @4ae497 unknown -> no change / no recompute
 	}
+	// ALWAYS log a valve press (rare + forensic -- the 2026-07-23 "boosted loop
+	// still cooked" field case could not be reconstructed without the detents)
+	DEBUG_STREAM << "[valve] " << GetName() << " valve -> detent " << valveState
+		<< (valveState == 0 ? "  (CLOSED -- this loop is now UNCOOLED)" : "")
+		<< "\n" << std::flush;
 	BTRecomputeCondenserValves((Entity *)owner);	// FUN_0049f788(this[0xd0]=owner Mech)
 }