HKS: Accessories: AFK

HKS A/F Knock Amp

HKS AFK - A/F Knock Amp v1 HKS AFK - A/F Knock Amp v2 Redesigned for 2008, the all new generation of the A/F Knock Amp, known as the AFK, now includes a new HKS AF sensor where the air/fuel ratio can be monitored accurately on the display. The AFK can now monitor and display dual A/F readings with the purchase of an additional AF sensor. The redesign of the new AFK features a sleek black case with a clear acrylic faceplate and a positive lit LCD offering a sophisticated look to match the new EVC.

The HKS AFK is an electronic monitoring device that displays two of the most vital engine conditions; engine knock and air/fuel ratio. Knock occurs when there is abnormal engine combustion, known as detonation, caused by a combination of improper A/F ratios and ignition spark. This can rob power, reduce engine longevity and even lead to catastrophic failure. The A/F Knock Amp utilizes the factory knock sensor allowing you to monitor, in real time, engine knock visually and audibly via headphones (not included). A warning function can be set for both engine knock and air/fuel ratio where an audible alert sounds if the preset warning is reached.


• HKS A/F Knock Amp v1 Installation Manual - [ pdf ]
• HKS A/F Knock Amp v2 Instruction Manual - [ pdf ]

Alternative Knock Detection Hardware

Knock Defender Very few people are prepared to pay 1000AUD+ just to have HKS AFK hardware, and another 1400AUD+ for a complete tune. Other knock detection cannot be used to their full potential due to not supporting the HKS-specific knock window signal. That has been a problem until now.

Knock Defender completely solves that problem.

DMS Electronics Design has developed a cost-effective knock detection hardware solution that is compatible with HKS F-CON V Pro Gold ECUs (v3.1 and higher), and also support other aftermarket ECUs (eg: Haltech, Link - any with knock window output signal from the ECU) for flexibility reasons, without being tied to one ECU manufacturer, and utilising existing OEM knock sensors.

You may ask "why"? The primary reason is because most people would like (or already have) access to a universal wideband O2 controller which are well priced, and do not need an integrated wideband and knock detection solution. Also, it will be priced very competitively, against HKS and third party knock detection hardware (eg: Link Knock Block, Knock Ears / Knock Box, phormula Knock Analyser, etc). Thirdly - full technical support, which is very lacking from HKS tuners and HKS themselves.

What's the benefit of Knock Defender? Precise ignition tuning can be performed, either on the dyno or on the road.

Knock Defender is now available from here

AFK "black limited" edition

The AFK came out in a black limited edition, with black case and negative backlight.

HKS AFK v2: Photos

HKS A/F Knock Amp - v2 - LCD 01 HKS A/F Knock Amp - v2 - LCD 02 HKS A/F Knock Amp - v2 - LCD 03
Thanks to Jan for the photos

HKS A/F Knock Amp v1: Photos

HKS A/F Knock Amp - v1 - Outside HKS A/F Knock Amp - v1 - Inside HKS A/F Knock Amp - v1 - MCU

Oxygen Sensor Specification

• AFK v1: NTK
• AFK v2: bosch LSU 4.2

HKS A/F Knock Amp: Setup in universal mode

AFK v1 and v2 can be connected to any ECU (eg: iS or v3.0 gold), but you'll need to connect it in universal mode. What this means is that the cam and crank signals must also be connected - whether 3 or 4 or 6 wires - and the AFK unit P10-P18 parameters all must be configured. Failure to do so will result in "error" message. (Brown and Purple wires should be omitted in this mode)

HKS A/F Knock Amp v1: Setup and Usage with F-CON V Pro v3.1+

• Connect {White,Grey} to knock sensors on engine.
• Connect Standand Signal Input {Brown} to F-CON V Pro PIN #61 or #55.
• Connect Knock Voltage Output {Purple} to F-CON V Pro PIN #15 or #23 or #24.

• To enter parameter configuration mode, press and hold MOD. To switch to next parameter, press MOD.
• To finish configuration, press and hold MOD.

A/F-Knock Amp Setup: (eg: 1JZ-GTE)
HKS AFK - v1 - Monitor Ssettings

HKS A/F Knock Amp v1: Knock Sensor Calibration

• Start engine.
• Press and hold MOD and
• Hold the engine at 1000 RPM in neutral gear and ensure there is no knocking by installing a set of headphones into knock amp.
• Press to initialise self-learning mode. (to stop, press ▼)
• self-learning mode will finish in 5 seconds and return to monitor mode. P04-P07 will have been updated.

For additional fine-tuning of knock sensor calibration, perform the following:
• In neutral gear, rev the engine to 4000 RPM and ensure there is no knock.
   - Increase parameter P06 (knock filter offset) to a higher value until knock level reads 0.
• In neutral gear, rev the engine over 4000 RPM and ensure there is no knocking.
   - Increase parameter P05 (knock filter multiplier) by 1 (0.1 units) until knock level reads a value of 0.
• Run the engine under high load in high gear and ensure there is no knocking.
   - Increase parameter P05 (knock filter multiplier) by 1 (0.1 units) until knock level reads a value of 0.

Knock Sensitivity:
• sensitivity can be adjusted with parameter P04. Increase number will decrease sensitivity. Increasing by 2x will decrease sensivity by half.

HKS A/F Knock Amp v1: Setting PowerWriter software

• Open Ignition 2 tab of Parameter Setting.
• Set Knock Level 100 Voltage to 4500
• Set Knock Level 0 Voltage to 500
• Set Knock Detect Timing to -10
• Set Knock Detect Port for two knock sensors on 6 cylinder to:
    - IGN #1,#3,#5 to Port 1, and
    - IGN #2,#4,#6 to Port 2.
• For F-CON V Pro Standard Signal Input {Brown} wire connection to:
    a) Twin Injector Adaptor PIN 61, select Not Select for Twin Injector Adaptor in Twin INJ tab of Parameter Settings.
    b) Option Switch Output #2 PIN 55, select Knock Timing for OPTION Switch Output in Option 1 tab of Parameter Settings.
• For Knock Voltage Output {Purple} wire, set Knock in Control tab of Parameter Settings:
    - Fuel GCC INPUT (Pin 15) - Set Fuel GCC
    - Option Voltage INPUT #1 (Pin 23) - Set Voltage #1
    - Option Voltage INPUT #2 (Pin 24) - Set Voltage #2
• Add Knock Level to Data Monitor. (Link, show Data Monitor, then select Knock Level for View Item in Setting)

HKS A/F Knock Amp v1: Connection Diagram

HKS A/F-KnockAmp ( PDF | png )