Honda K series engine

Honda K series engine

The Honda K-series engine is a line of four-cylinder four-stroke car engine introduced in 2001. The K-series engines are equipped with DOHC
 valvetrains and use roller rockers to reduce friction. The engines use a coil-on-plug, distributorless ignition system with a coil for each spark plug. This system forgoes the use of a conventional distributor-based ignition timing system in favor of a computer-controlled system that allows the ECU to control ignition timings based on various sensor inputs.




 




General Information

Haltech Elite Series Setting
Value
Number of Cylinders
4
Capacity
1998cc 2.0L or 2354cc 2.4L
Firing Order
1-3-4-2
Engine Type
Piston 4 - Stroke
Injection Mode
Sequential
Number of Inj
4
Inj Flow/Size
310cc
Inj Current Setting
High
Ignition Mode
Direct Fire
Ignition Edge
Falling
Ignition Dwell Mode
Constant Charge
Trigger Tooth Pattern
12+1
Home Tooth Pattern
4+1
ESP Trigger Pattern
Honda K20
TDC Angle

311


Trigger Sensor Type
Hall
Trigger Sensor Edge
Falling
Trigger Filter Level
0
Trigger Pullup
Strong
Trigger Ground Ref
-
Home Sensor Type
Hall
Home Sensor Type
Falling
Home Filter Level
0
Home Pull-up
Strong
Home Ground Ref
-
Home Min RPM
1000
Quick Start
Enabled
Notes

This applies for the following :  K20A/K24A DC5/EP3 K20Z1






Recommended Haltech ECU

Honda Civic EP3 Chassis
Platinum Pro Plug -In ECU a direct OEM replacement ECU P/N HT-055047

Elite 1000 + Honda Civic EP3 Plug n Play Adapter Harness Kit P/N HT-150841

Elite 1500 + Honda Civic EP3 Plug n Play Adapter Harness Kit P/N HT-150960

Note : The above items will also apply to the Acura RSX/Honda Integra DC5 02-04 Chassis

Acura RSX/Honda Integra DC5 05-06 Chassis
Platinum Pro Plug-In ECU a direct OEM replacement ECU P/N HT-055048

Elite 1000 + Honda Integra DC5 Plug n Play Adapter Harness Kit P/N HT-150842

Elite 1500 + Honda Integra DC5 Plug n Play Adapter Harness Kit P/N HT-150961

Other Chassis with K-Series engine
Elite 1000 + Basic Universal Wire-in Harness Kit P/N HT-150802
https://www.haltech.com/product/ht-150802-elite-1000/

Elite 1000 + Premium Universal Wire-in Harness Kit P/N HT-150804
https://www.haltech.com/product/ht-150804-elite-1000/

Other Chassis with K-Series engine and Drive By Wire required

Elite 1500 + Basic Universal Wire-in Harness Kit P/N HT-150902
Elite 1500 + Premium Universal Wire-in Harness Kit P/N HT-150904

Sensor Information

Trigger System

The K-series uses a crank sensors and 2x cam sensors. The crank trigger has 12x teeth plus 1x extra tooth used for crank sync.  The exhaust cam sensor is used for engine sync, and the inlet cam sensor is used for iVTEC inlet cam positioning.  All sensors are Hall Effect.

Crank Trigger


Cam Trigger




Trigger Configuration

This information is available in the K20 base maps that come with the ESP Software installation.



Crank Sensor (CKP)

The K20 has a Hall Effect crank sensor.



Wiring

Looking into sensor pins



K20 Crank Sensor Wiring (Blue Connector)

Pin
Description
Haltech Connection (Trigger 4-core)
1
Signal
Trigger + (Yellow)
2
Signal Ground
Signal Ground (Blue)
3
12V+ Swtiched
12V+ (Red)

K24 Crank Sensor Wiring (Grey Connector)
Pin
Description
Haltech Connection (Trigger 4-core)
1
12V+ Switched
12V+ (Red)
2
Signal
Trigger + (Yellow)
3
Signal Ground
Signal Ground (Blue)







Cam Sensor

Both the inlet and exhaust cam sensors are Hall Effect.  The Exhaust Cam Sensor is used for the Home input to the ECU.  The Inlet Cam Sensor is used for iVTEC control.



From rear of connector w/ release tab facing up.
1 | 2 | 3

Pin
Description
Haltech Connection (Home 4-core)
1
Signal -  In Cam (Green) Ex Cam (Blue/White)
Home + (Yellow)
2
0V Brown/Yellow
Signal Ground (Blue)
3
12V Yellow/Black
12V (red)












Ignition System

The K20 engine uses Direct Fire with an ignition coil per spark plug.  The coils have an internal igniter module and are wired directly to the ECU.
Settings are Constant Charge with a Falling edge.  Selecting incorrect settings will damage the coil and possibly the ECU.



Pin
Description
Haltech Connection
1
ECU Signal
Ignition Output
2
Ground to Cylinder Head
---
3
12V+ Switched
---


Dwell











Injector Data

Flow

The injector flow rate is measured with the injectors held wide open at 100% duty.  For fuel systems with a fixed regulator pressure (often returnless systems) that is not referenced to manifold pressure the flow needs to be mapped over Manifold Pressure for accurate tuning.  The K20 has a non-returning fuel system with a pressure regulator not connected to inlet manifold pressure.  As such teh injector flow rate should be mapped over Injector Pressure Differential to maintain correct injector flow with changing manifold pressure.

If a fuel pressure sensor is not connected then the Base Fuel Pressure setting will impact the fuel control.





Dead Time

When an injector is commanded to open for a certain amount of time, the dead time is the amount of time the injector is not actually open during this period.  It covers the time to energise the solenoid and begin to open and the time to close as well.  There are also transient periods during which the injector is opening and closing where fuel flow is not at full capacity so this lost peak flow period is also taken into account.  













Variable Cam Control (iVTEC and VTEC)

The K20 engine uses both a continuously variable intake cam timing system (iVTEC) and a switched on/off variable lift system (VTEC).

Cam Control (iVTEC)

The Cam Control function is used for the iVTEC system.  This requires the inlet cam sensor to be configured and an output to drive the oil solenoid.



Cam Control Switched (VTEC)

The Cam Control Switched function is used for the VTEC system. It requires only a output that has a high side drive capability. For the Elite ECU range a Stepper Output should be used for this purpose.





System Description


Why does Honda impletment this system? They implement it to improve optimum engine effeciency which results in more horsepower and better fuel economy. Since the camshaft spins half as fast as the crankshaft, optimum valve over-lap and timing is different at every RPM.

Muscle cars have that lope at idle because of the camshaft design. By designing a camshaft specifically for high RPM horsepower, you must use sacrifice how smooth the engine runs at low RPM. This sacrifice is what causes the engine lope at idle.


VTEC-E

VTEC-E is quite different from the standard VTEC, because Honda did not design it for optimal horsepower at high RPMs, instead they designed for optimal fuel efficiency at low RPMs. VTEC-E does this by effectively forcing the engine to run as a 12 valve engine instead of its normal 16 valves. It does this by not allowing the second intake valve to open fully

The VTEC-E design decreases fuel consumption quite a lot but lacks the high horsepower numbers that the standard VTEC produces. This type of VTEC is standard on many of the fuel-efficient Honda models.


VTC

Before we jump into i-VTEC, we quickly want to cover VTC to give you a better understanding of how all this works. Variable Timing Control (VTC), is a mechanism that allows the camshaft gear to be continuously variable. The variable camshaft gear allows the valve overlap to be adjusted at any RPM. By adjusting the valve overlap agt different RPM ranges, effeciency and power levels are greatly improved.

Honda uses this system on the intake camshaft but not on the exhaust camshaft, as the gains from having VTC on the exhaust camshaft are minute. VTC is always active and adjusting valve overlap for optimal engine efficiency and power at any given RPM.


iVTEC

Intelligent Variable Timing (and lift) Electronically Controlled (iVTEC), is a system that combines VTEC and VTC into one unit. As you can imagine, combined the best of both world results in an incredibly efficient and powerful engine. The VTEC part of the system has two different camshaft profiles, one for low rpms, and one for high rpm. The VTEC part of the system allows valve overlap to be adjusted at any moment, resulting in much greater efficiency and slightly better performance.

K20A2: The K20A2 VTEC system engages at 5,800 RPM, whilst the VTC system is always active. These two systems combined (iVTEC) produce about ten horsepower more than just VTEC alone. The K20A2 is available in the Acura RSX Type S, and TSX.

K20A3: The K20A3 iVTEC system is far different than the A2’s system. It is VTEC-E with VTC, and really shouldn’t even be classified as iVTEC. At low RPM only one intake valve opens, which decreases fuel consumption, then at 2,200 rpm, it engages the second intake valve, allowing it to operate like a normal 16 valve engine.


Much like the A2’s iVTEC system, the VTC is always active on the A3. K20A3 comes in the RSX base, Civic SI, Accord, CRV, and Element.


How Does it Increase Horsepower?

How the VTEC system increase horsepower may be slightly confusing, so let me break it down for you. Horsepower is just a measure of Torque X RPM. To increase torque, you must let more air and fuel into the engine.

If the valves must open further and for longer, the amount of air being sucked into the cylinder can be increased. Since the camshaft spins half as fast as the crankshaft, it cannot be optimized for all RPM ranges. Having multiple camshaft lobes allows you to maximize lift and duration for various RPM ranges.

Since the camshaft is optimized for both high and low rpm ranges, it makes more torque in those ranges. More torque, especially at high RPMs, equals more horsepower.


Summary

There is a lot of information to take in. Remember, iVTEC combines VTEC and VTC into one unit in the K20A2. iVTEC in the K20A3 is a combination of VTEC-E and VTC, which is much more of a fuel efficiency focused system.










Throttle Position Sensor (TPS)



Pin
Description
Haltech Connection
1
Signal Ground
Signal Ground (Black/White)
2
Signal
Spare AVI (AVI-10 White)
3
5V+
5V (orange)









MAP Sensor

The K20 comes with a MAP sensor in the intake.


Pin
Description
Haltech Connection
1
5V+
5V+ (orange)
2
Signal
Spare AVI (AVI-9 Yellow)
3
Signal Ground
Signal Ground (black/white)







Vehicle Speed Sensor

The K20 has a Hall Effect speed sensor.


MY02-04
Pin
Description
Haltech Connection
1
Signal Ground
Signal Ground (Black/White)
2
12V+
---
3
Signal


MY05
Pin
Description
Haltech Connection
1
12V+
---
2
Signal

3
Signal Ground
Signal Ground (Black/White)















OEM ECU



ECU Pinout





        









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