Sale ends todayGet 30% off any course (excluding packages)

Ends in --- --- ---

Link G4 Plus Software Tutorial: Anti Lag

Watch This Course

$99 USD

Or 8 weekly payments of only $12.38 Instant access. Easy checkout. No fees. Learn more
Course Access for Life
60 day money back guarantee

Anti Lag


00:00 - One of the advanced motorsport functions included with the G4+ is anti lag.
00:05 Anti lag is used in turbocharged cars to help maintain turbo speed when the throttle is closed, reducing lag.
00:13 Anti lag will result in extreme temperatures in the exhaust manifold and turbocharger.
00:18 It requires very careful tuning and can result in damage to the turbo, manifold or engine.
00:25 Only set up anti lag if you're familiar with the system and understand the risks.
00:31 An anti lag system is more than just the software functions and will require some way of introducing extra air into the engine during anti lag operation.
00:40 This is usually achieved with either an air bypass solenoid or by kicking the throttle body open.
00:47 The anti lag parameters can be accessed through the ECU settings menu by clicking on the motorsport tab and then anti lag.
00:55 If we click on anti lag we can adjust the settings to suit.
01:00 First we need to turn the anti lag system on as by default it is disabled.
01:05 We now have a number of parameters to configure.
01:09 Anti lag system arming controls how the anti lag is activated.
01:14 We can use a switch connected to a digital input for instance or in group N applications, we can have the anti lag system remain active continuously.
01:24 The G4+ gives the option of incorporating an anti lag ignition cut table.
01:29 This table is optional and if you want to utilise it, turn it on.
01:33 ISC override can be used to force the idle speed motor to a wide open position when anti lag is active.
01:40 This on its own will not generally flow enough extra air for good anti lag operation though.
01:46 The anti lag retard mode specifies if the ignition retard table is in degrees, percentage or degrees absolute.
01:54 This has a big impact on the amount of ignition retard so it's important to understand how this will affect the final ignition timing.
02:02 Degrees will add the specified amount of ignition timing to the normal ignition table.
02:07 To retard the timing, we need to enter a negative value.
02:11 Percentage will add a percentage to the numbers in the ignition table.
02:16 Again we need to enter a negative percentage to retard the timing.
02:20 For example if the current ignition timing is 30° and the retard percentage is -100, 30° will be removed, resulting in zero degrees final ignition timing.
02:32 If we enter -200% we will end up with a timing of -30°.
02:38 Degrees absolute will result in the ignition advance in the retard table being used whenever anti lag is active.
02:44 For example if -20 is entered in the table, we will see -20° ignition advance.
02:50 Any time there is a zero in the retard table, the ignition timing will revert to the main ignition map numbers.
02:58 Next we have the AL enable RPM and the AL enable TP.
03:03 For the anti lag to become active the RPM and throttle position must exceed both of these values.
03:10 Normally these are set to a point that the anti lag won't become active during normal cruising.
03:15 The anti lag deactivation time specifies how long the anti lag will remain active if the RPM and throttle position falls outside the enable paraeters.
03:25 This ensures the anti lag doesn't remain active when you don't want it.
03:30 Five seconds is a typical value.
03:33 The cyclic idle function is useful when competition rules don't allow for an external air bypass solenoid and the throttle body is constantly held open.
03:43 Cyclic idle is used to limit engine RPM to a normal idle speed when the anti lag is not active.
03:49 If the cyclic idle is enabled, there are a few more parameters to configure.
03:54 Cyclic idle low and cyclic idle high set the throttle range over which the cyclic idle is active.
04:02 These parameters are used to smooth the transition between idle and driving.
04:06 Typically cyclic idle high will be between 3 - 5% higher than cyclic idle low.
04:13 Cyclic idle low must also be set slightly higher than the throttle opening at idle.
04:18 Typically by approximately 2%.
04:21 For example if the throttle position at idle was 20% then cyclic idle low would typically be around 22% and cyclic idle high would be around 25%.
04:34 Cyclic idle limit is the idle speed that the ECU will target when the throttle position is below the cyclic idle low value.
04:43 Advanced mode specifies whether the ECU will use the default limiting parameters or whether you wish to adjust these to suit.
04:50 If you've chosen the cool down mode you will also have a parameter called cool down time out to set how long the cyclic idle will remain active.
05:00 There are four modes for the cyclic idle.
05:03 When it's turned off it will not function.
05:06 Always on mean the cyclic idle will always be active regardless if the anti lag is armed or off.
05:13 Cool down means the cyclic idle will only remain active for a fixed time after the anti lag transitions from active to armed.
05:21 On equals system armed means the cyclic idle will only be active when the anti lag is armed.
05:29 The G4+ allows two sets of tables to be used for the anti lag parameters.
05:34 This can be used to provide a mild and aggressive anti lag setup that can be selected using a digital input for example.
05:41 The dual tables menu lets you select how the dual anti lag tables are enabled if you wish to use them.
05:49 Lastly we have the anti lag ignition retard, anti lag fuel and anti lag cut tables.
05:56 These can be adjusted to give the desired anti lag performance.
06:00 It's important to understand that all of the anti lag tables are overlaid on top of the normal fuel and ignition tables.
06:08 You don't need to actually tune every zone in these tables but rather just the areas where the anti lag is effective which are normally down at low throttle openings.