61:
164:
146:, which processes the signal to determine if, in fact, knock is occurring. If it is, then the control unit activates a solenoid valve that directs boost pressure to the turbocharger's pneumatically controlled wastegate, that opens to bypass exhaust gases from the turbocharger directly to the exhaust pipe, lowering turbo
154:
may be connected. This LED will then light up if knock is detected. Because the knock sensor becomes less accurate at high revolutions, the APC tapers maximum boost pressure after approximately 4,500 RPM.
190:
in the instrument panel. Although knock sensors are common even on non-turbocharged and turbocharged engines today, Saab has continued to use the APC name prominently as a differentiating feature.
53:
in 1982, and the APC was fitted to all subsequent 900 Turbos through 1993 (and 1994 convertibles), as well as 9000 Turbos through 1989. The APC was sold to
Maserati to equip the carbureted
150:
pressure until the knock subsides. Knock events that are managed by the APC can be discerned when the in-dash boost needle "twitches" slightly. The APC unit has a 'knock' output where an
120:, and uses these inputs to control a solenoid valve that trims the rate of rise of pressure as well as the maximum pressure by directing boost pressure to the turbocharger's pneumatic
289:
102:
The APC controls boost pressure and the overall performance, specifically the rate of rise and maximum boost level - and it detects and manages harmful knock events.
282:
857:
142:) bolted to the engine block responds to unique frequencies caused by engine knock. The sensor generates a small voltage that is sent to the
197:
under normal driving conditions, the short white dash is atmospheric pressure (engine off), the orange scale is where there is safe turbo
216:/APC system, available in 9000 models only. The DI/APC system managed knock not only by decreasing boost via a solenoid but by retarding
275:
796:
474:
198:
771:
355:
88:
946:
298:
907:
821:
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718:
626:
212:
Saab integrated the APC's boost control functionality with ignition control in 1990 with the introduction of the
902:
743:
452:
229:
57:, with different settings for the Biturbo, and was known as the Maserati Automatic Boost Controller (MABC).
677:
143:
87:(initially, 8.5:1 as opposed to 7.2:1, and, on 16-valve variants introduced in 1985, 9.0:1). This improved
499:
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34:) was the first engine knock and boost control system. The APC was invented by
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186:) models with this unit include the APC name displayed on a non-numeric boost
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40:
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as well; DI/APC also managed the engine's basic ignition timing.
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To control the turbocharger, the APC monitors the engine's
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193:The white area on the left side of the scale shows
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8:
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201:, the red scale is boost above 0.5 - 0.7
356:Crankcase ventilation system (PCV valve)
95:without causing engine damage caused by
245:
205:where the wastegate may be opened or a
7:
25:
458:Overhead valve (pushrod) layout
38:at the Swedish car maker SAAB.
1:
28:Automatic Performance Control
209:due to overboost may occur.
255:"Turbocharger with a brain"
253:Jack, Keebler (July 1982).
46:SAAB introduced it on the
968:
299:Internal combustion engine
916:
767:Diesel particulate filter
719:Idle air control actuator
660:Engine control unit (ECU)
305:
83:The APC allowed a higher
832:Viscous fan (fan clutch)
744:Throttle position sensor
453:Overhead camshaft layout
230:Saab Information Display
371:Core plug (freeze plug)
144:electronic control unit
91:and allowed the use of
175:
80:
166:
63:
41:U.S. patent 4,372,119
612:Compression ignition
762:Catalytic converter
180:Full Pressure Turbo
130:To detect knock, a
70:pressure transducer
18:Full Pressure Turbo
888:Knocking / pinging
480:Combustion chamber
176:
81:
947:Engine technology
934:
933:
903:Stratified charge
670:Electrical system
652:Engine management
485:Compression ratio
425:Starter ring gear
324:rotating assembly
93:low-octane petrol
85:compression ratio
16:(Redirected from
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777:Exhaust manifold
642:Spark plug wires
528:Boost controller
515:Forced induction
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285:
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261:. July 1982: 85.
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55:Maserati Biturbo
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21:
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908:Top dead centre
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465:Tappet / lifter
448:Flathead layout
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323:
314:
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259:Popular Science
252:
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218:ignition timing
195:manifold vacuum
161:
159:APC boost gauge
116:via a pressure
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39:
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5:
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797:Cooling system
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754:Exhaust system
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579:Fuel injection
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346:Connecting rod
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188:pressure gauge
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111:inlet manifold
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76:solenoid valve
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51:Saab H engines
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810:Water cooling
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787:Oxygen sensor
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702:Intake system
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693:Starter motor
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632:Ignition coil
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564:Petrol engine
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559:Diesel engine
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523:Blowoff valve
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440:Cylinder head
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331:Balance shaft
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138:(basically a
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132:piezoelectric
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48:turbo charged
44:
42:
37:
36:Per Gillbrand
33:
29:
19:
817:Electric fan
617:Coil-on-plug
543:Turbocharger
538:Supercharger
410:Main bearing
400:Firing order
390:Displacement
336:Block heater
320:Engine block
308:Part of the
307:
258:
248:
211:
192:
183:
179:
177:
129:
104:
101:
89:fuel economy
82:
73:control unit
67:knock sensor
45:
31:
27:
26:
841:Lubrication
805:Air cooling
622:Distributor
574:Fuel filter
552:Fuel system
533:Intercooler
500:Timing belt
490:Head gasket
420:Piston ring
169:boost gauge
941:Categories
893:Power band
853:Oil filter
827:Thermostat
772:EGT sensor
734:MAF sensor
729:MAP sensor
714:Air filter
678:Alternator
637:Spark plug
569:Carburetor
495:Rocker arm
435:Valvetrain
366:Crankshaft
310:Automobile
241:References
167:turbo/APC
140:microphone
118:transducer
627:Glow plug
589:Fuel tank
584:Fuel pump
351:Crankcase
122:wastegate
926:Category
871:Dry sump
867:Wet sump
858:Oil pump
822:Radiator
739:Throttle
599:Ignition
470:Camshaft
395:Flywheel
376:Cylinder
361:Crankpin
224:See also
207:fuel cut
173:Saab 900
125:actuator
114:pressure
898:Redline
782:Muffler
683:Battery
607:Magneto
235:Trionic
921:Portal
709:Airbox
688:Dynamo
415:Piston
405:Stroke
384:layout
312:series
136:sensor
134:knock
881:Other
505:Valve
475:Chest
199:boost
178:Saab
171:in a
148:boost
97:knock
952:Saab
863:Sump
380:bank
341:Bore
109:and
848:Oil
437:and
322:and
203:bar
184:FPT
152:LED
107:RPM
32:APC
943::
869:,
382:,
257:.
214:DI
127:.
99:.
873:)
865:(
386:)
378:(
291:e
284:t
277:v
182:(
30:(
20:)
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