diff --git a/firmware/controllers/trigger/decoders/trigger_structure.cpp b/firmware/controllers/trigger/decoders/trigger_structure.cpp
index 425384ae63..1f43828b82 100644
--- a/firmware/controllers/trigger/decoders/trigger_structure.cpp
+++ b/firmware/controllers/trigger/decoders/trigger_structure.cpp
@@ -159,7 +159,10 @@ angle_t TriggerWaveform::getAngle(int index) const {
 	int crankCycle = index / privateTriggerDefinitionSize;
 	int remainder = index % privateTriggerDefinitionSize;
 
-	return getCycleDuration() * crankCycle + getSwitchAngle(remainder);
+	auto cycleStartAngle = getCycleDuration() * crankCycle;
+	auto positionWithinCycle = getSwitchAngle(remainder);
+
+	return cycleStartAngle + positionWithinCycle;
 }
 
 void TriggerWaveform::addEventClamped(angle_t angle, trigger_wheel_e const channelIndex, trigger_value_e const stateParam, float filterLeft, float filterRight) {
@@ -418,7 +421,10 @@ void findTriggerPosition(TriggerWaveform *triggerShape,
 
 	int triggerEventIndex = details->triggerIndexByAngle[(int)angle];
 	angle_t triggerEventAngle = details->eventAngles[triggerEventIndex];
-	if (angle < triggerEventAngle) {
+	angle_t offsetFromTriggerEvent = angle - triggerEventAngle;
+
+	// Guarantee that we aren't going to try and schedule an event prior to the tooth
+	if (offsetFromTriggerEvent < 0) {
 		warning(CUSTOM_OBD_ANGLE_CONSTRAINT_VIOLATION, "angle constraint violation in findTriggerPosition(): %.2f/%.2f", angle, triggerEventAngle);
 		return;
 	}
@@ -428,7 +434,7 @@ void findTriggerPosition(TriggerWaveform *triggerShape,
 		chibios_rt::CriticalSectionLocker csl;
 
 		position->triggerEventIndex = triggerEventIndex;
-		position->angleOffsetFromTriggerEvent = angle - triggerEventAngle;
+		position->angleOffsetFromTriggerEvent = offsetFromTriggerEvent;
 	}
 }
 
diff --git a/firmware/controllers/trigger/trigger_decoder.cpp b/firmware/controllers/trigger/trigger_decoder.cpp
index 1866d9b9cd..db81ecf7c0 100644
--- a/firmware/controllers/trigger/trigger_decoder.cpp
+++ b/firmware/controllers/trigger/trigger_decoder.cpp
@@ -170,6 +170,12 @@ void prepareEventAngles(TriggerWaveform *shape,
 
 	memset(details->eventAngles, 0, sizeof(details->eventAngles));
 
+	// this may be <length for some triggers like symmetrical crank Miata NB
+	int triggerShapeLength = shape->privateTriggerDefinitionSize;
+
+	assertAngleRange(shape->triggerShapeSynchPointIndex, "triggerShapeSynchPointIndex", CUSTOM_TRIGGER_SYNC_ANGLE2);
+	efiAssertVoid(CUSTOM_TRIGGER_CYCLE, engine->engineCycleEventCount != 0, "zero engineCycleEventCount");
+
 	for (int eventIndex = 0; eventIndex < length; eventIndex++) {
 		if (eventIndex == 0) {
 			// explicit check for zero to avoid issues where logical zero is not exactly zero due to float nature
@@ -177,15 +183,25 @@ void prepareEventAngles(TriggerWaveform *shape,
 			// this value would be used in case of front-only
 			details->eventAngles[1] = 0;
 		} else {
-			assertAngleRange(shape->triggerShapeSynchPointIndex, "triggerShapeSynchPointIndex", CUSTOM_TRIGGER_SYNC_ANGLE2);
-			unsigned int triggerDefinitionCoordinate = (shape->triggerShapeSynchPointIndex + eventIndex) % length;
-			efiAssertVoid(CUSTOM_TRIGGER_CYCLE, engine->engineCycleEventCount != 0, "zero engineCycleEventCount");
-			int triggerDefinitionIndex = triggerDefinitionCoordinate >= shape->privateTriggerDefinitionSize ? triggerDefinitionCoordinate - shape->privateTriggerDefinitionSize : triggerDefinitionCoordinate;
-			float angle = shape->getAngle(triggerDefinitionCoordinate) - firstAngle;
+			// Rotate the trigger around so that the sync point is at position 0
+			auto wrappedIndex = (shape->triggerShapeSynchPointIndex + eventIndex) % length;
+
+			// Compute this tooth's position within the trigger definition
+			// (wrap, as the trigger def may be smaller than total trigger length)
+			auto triggerDefinitionIndex = wrappedIndex % triggerShapeLength;
+
+			// Compute the relative angle of this tooth to the sync point's tooth
+			float angle = shape->getAngle(wrappedIndex) - firstAngle;
+
 			efiAssertVoid(CUSTOM_TRIGGER_CYCLE, !cisnan(angle), "trgSyncNaN");
+			// Wrap the angle back in to [0, 720)
 			fixAngle(angle, "trgSync", CUSTOM_TRIGGER_SYNC_ANGLE_RANGE);
+
 			if (engineConfiguration->useOnlyRisingEdgeForTrigger) {
-			    assertIsInBounds(triggerDefinitionIndex, shape->isRiseEvent, "isRise");
+				efiAssertVoid(OBD_PCM_Processor_Fault, triggerDefinitionIndex < triggerShapeLength, "trigger shape fail");
+				assertIsInBounds(triggerDefinitionIndex, shape->isRiseEvent, "isRise");
+
+				// In case this is a rising event, replace the following fall event with the rising as well
 				if (shape->isRiseEvent[triggerDefinitionIndex]) {
 					riseOnlyIndex += 2;
 					details->eventAngles[riseOnlyIndex] = angle;
diff --git a/unit_tests/tests/trigger/test_symmetrical_crank.cpp b/unit_tests/tests/trigger/test_symmetrical_crank.cpp
index 48081524a2..b77d5f4110 100644
--- a/unit_tests/tests/trigger/test_symmetrical_crank.cpp
+++ b/unit_tests/tests/trigger/test_symmetrical_crank.cpp
@@ -21,20 +21,25 @@ TEST(engine, testAngleLogicInSymmetricalCrankIssue2980) {
 
 	TriggerWaveform * form = &ENGINE(triggerCentral.triggerShape);
 
-	ASSERT_EQ(form->findAngleIndex(triggerForm, 10), 1);
-	ASSERT_EQ(form->findAngleIndex(triggerForm, 180), 5);
+	#define EXPECT_FINDANGLE(angle, idx) EXPECT_EQ(form->findAngleIndex(triggerForm, angle) & 0xFFFF'FFFE, idx);
 
-	ASSERT_EQ(form->findAngleIndex(triggerForm, 310), 5);
-	ASSERT_EQ(form->findAngleIndex(triggerForm, 540), 5);
+	// Check one angle just after every trigger tooth, for two full revolutions (720 degrees, one engine cycle, 4 loops of the trigger)
 
-	ASSERT_EQ(form->findAngleIndex(triggerForm, 640), 5);
-	ASSERT_EQ(form->findAngleIndex(triggerForm, 650), 7);
-	ASSERT_EQ(form->findAngleIndex(triggerForm, 660), 15);
-	ASSERT_EQ(form->findAngleIndex(triggerForm, 670), 15);
-	ASSERT_EQ(form->findAngleIndex(triggerForm, 680), 15);
+	// First quarter
+	EXPECT_FINDANGLE(0 * 180 + 5, 0);		// 5
+	EXPECT_FINDANGLE(0 * 180 + 115, 2);		// 115
 
-	ASSERT_EQ(form->findAngleIndex(triggerForm, 700), 15);
-	ASSERT_EQ(form->findAngleIndex(triggerForm, 710), 15);
+	// Second quarter
+	EXPECT_FINDANGLE(1 * 180 + 5, 4);		// 180+5 = 185
+	EXPECT_FINDANGLE(1 * 180 + 115, 6);		// 180+115 = 295
+
+	// Third quarter
+	EXPECT_FINDANGLE(2 * 180 + 5, 8);		// 360+5 = 365
+	EXPECT_FINDANGLE(2 * 180 + 115, 10);	// 360+115 = 475
+
+	// Fourth quarter
+	EXPECT_FINDANGLE(3 * 180 + 5, 12);		// 540+5 = 545
+	EXPECT_FINDANGLE(3 * 180 + 115, 14);	// 540+115 = 655
 }
 
 TEST(engine, testSymmetricalCrank) {