Honda FK8 Type R COBB Custom Launch Control Tuning Guide

 

Applicable Vehicles

2017-2021 Civic Type R

Intro

Unlike many other performance vehicles, the Type R doesn’t offer a factory launch control system. In it’s place the car offers a stationary rev limiter of 3500rpm. This can help to regulate engine speed making a basic launch possible, however it uses the throttle to control RPM, leading to a low maount of airflow and little to no boost pressure. The lack of boost pressure and thus available torque from the engine can lead to a sluggish start.

COBB Custom Launch Control for Honda Civic Type R is a comprehensive system allowing multiple benefits. The first feature is a multi-part system that includes dynamic engine speed limiting and load targeting, allowing you to regulate and optimize wheel slip for a better launch. The system can even remain active through multiple gears in order to prevent excess wheel spin in traction limited vehicle speeds. The second function is a limiter that uses ignition and/or fuel cut instead of a throttle closure to build and maintain a target boost level allowing you to have a more aggressive launch with more power immediately available.


Dynamic RPM Limit (Rev Limiting):

One of the most valuable features of the CCF Launch Control system is the ability to limit engine speed based on undriven wheel speed. This allows you to indirectly target a specific ratio of slip between the front and rear wheels.

 

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Rev Limit (LC) Table

This 3d table shows undriven Wheel Speed (via the rear wheels) as the X-Axis, with the Accessport User Adjustable LC Rev Limit Slot as the Y-Axis (For more information see the guide https://cobbtuning.atlassian.net/wiki/spaces/PRS/pages/3172859905. The Engine Speed (RPM) on the Z-axis represents the active RPM limit used when launch control is active, given the x and z conditions.

What this means is that you’re able to adjust the RPM limiter based on wheel speed allowing the car to begin accelerating and stay in launch control even if the front wheels are still slipping. Allowing the rpm limit to come up can help prevent the car from bogging once it does regain traction. Contrary to what most people would expect, an amount of wheel slip is typically present when undergoing maximum acceleration depending on the tires and driving surface.

As the car accelerates from a launch, typically the driven wheels will move a little faster than the actual ground speed of the vehicle. If power from the engine isn’t maintained, or as the car accelerates, that difference will (should) get smaller. If the engine gets to a point that it can’t drive the wheels as quickly as the car is moving it will typically result in the engine bogging down and the car slowing. If the engine continues to drive the wheels faster than the speed it is travelling you’ll end up with constant wheelspin/smoke etc. The whole goal here is to keep the slip ratio (The difference of the driven speed of the tire in relation to vehicle speed) at an optimum point where it has enough wheel slip and enough acceleration that the car gains speed rapidly and the engine doesn’t bog down.

As the actual engine speed (RPM) approaches the dynamic rev limit, ignition-based torque reductions will activate and reduce engine torque preventatively in order to avoid over-shooting the rpm limit. In effect the reduction of torque operates like a basic ignition based traction control system. If the ignition based torque reduction is insufficient to keep engine speed under control and the RPM exceeds the value in the Rev Limit (LC) table a fuel cut limiter will activate.

The table Maximum RPM for Fuel Cut uses a combined ignition and fuel cut to control RPM when the value is exceeded. In our OTS maps we want to use this for any RPM target so we set it to 0 to always be used.

The wheel speed axis is adjustable to allow launch control to remain active and correct differently at different speeds and into multiple gears. The values in the COBB OTS maps are set to remain active through first and second gears. In order to keep the LC system activated the driver will need to do a flat-foot-shift from 1st to 2nd gear as the accelerator pedal needs to stay above the Accelerator Pedal Position Min. of 80% in order for launch control to stay engaged.

for more information on how to use flat-foot shift check out our guide https://cobbtuning.atlassian.net/wiki/spaces/PRS/pages/3172892673

 


Dynamic Load Targeting

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In order to optimize how effective the rpm limiting can be and reduce the amount of time reducing torque through ignition timing, there is also a dynamic Load Target that allows you to adjust the load target during launch control. Similar to the Rev Limit the Load Target is adjusted based on wheel speed, allowing you to optimize the wheel slip. Unlike the rpm limit, it utilises engine speed as the x-axis allowing you to adjust the target load% over a range of the engine’s performance to hit and maintain your target during the launch.

Like Rev Limit (LC) this table can be used over multiple gears as long as COBB Flat-Foot Shift is used to keep the accelerator pedal within the required range.

 

Depending on the track conditions, the Accessport offers an adjustment multiplier to users to tweak the load target as needed. It’s possible to go from 75% of the target load to 125%. For more information on how to use that feature check out the page https://cobbtuning.atlassian.net/wiki/spaces/PRS/pages/3172859905. An example use case would be that the surface is very loose and they need to turn down the output, or the surface is very grippy and the car isn’t maintaining the target rpm/load for launch without bogging down and they would turn up the output.

Since users are able to adjust the load target with no regard for what is set as the target, it’s important to set the Launch Control Scaled Max to establish a hard limit for load after any adjustments from the AP. This will prevent the load from exceeding a safe limit in the event that an end-user adjusts this to more than what the engine would be able to hold.


Interaction with Stock Rev Limiter Functions:

Several factory tables relating to rev limit hysteresis, integral and proportional gains for predictive torque reductions in engine speed limiting, and wastegate control have been modified in addition to our custom code.  These tables have been modified to manage the response time and duration of fuel- and ignition-based torque reductions, maximizing boost response while stationary and in-gear.

Rev Limiter Response

A new table group has been added under Rev Limiter Tables called Rev Limiter Response.  These tables are always active, not just when launch control is active.  These new tables are key for optimizing a few different things. Firstly they can assist with boost response when stationary and preparing to launch, and secondly the reactivity and “stickiness” of torque reductions made when encountering the dynamic rev limit as the vehicle accelerates in launch control.

To prevent engine overspeed, the factory control strategy calculates a predicted engine speed, compares that to actual engine speed and the current engine speed limiter, and can utilize torque reductions to avoid overshooting the rev limit. This is done via

  • Ignition Cut RPM Offset

  • Predictive Rev Limiter Offset

  • Rev Limiter Offset (Fuel Cut)

  • Rev Limiter Offset (Fuel Cut) #2

  • I-Term Gain RPM Control

  • P-Term Gain RPM Control

  • Time Delta Engine Speed Check

Modification of these tables can increase or decrease the threshold between actual and predicted RPM as well as the rev limit where torque reductions can occur.  The I-Term and P-Term tables contribute to how the engine reacts in terms of maintaining rpm by modifying how torque is ramped back in after encountering the rev limiter.  We found that to optimize stationary boost response, strengthening these I- and P-Term effects while in gear zero (neutral) works best.  However, to prevent sluggish acceleration when in gear, weakening these effects (numerically increasing their values) helped to return to the desired torque (via spark) after the reduction more quickly after instances of reduction due to the dynamic rev limit.  Further tuning with these tables to fine tune traction and torque delivery may be necessary to optimize acceleration and quell wheel hop off the line.

Wastegate Control

The tables Wastegate Special Position – Engine Speed Threshold and Wastegate Special Position – Exh. Mass Flow (Fuel Cut) were modified in OTS to ensure that the wastegate stays shut while on the stationary rev limiter. By keeping the wastegate shut it has the effect of increasing boost immediately available off the line.  Similarly, if attempting to launch with significantly more boost pressure than what OTS creates (4-6psi), increasing the Exh. Mass Flow (Fuel Cut) table may be necessary.

VTC Control

Although this table was not modified in OTS, we added a table to the VTC Tables group called Max. Engine Speed (Spool).  This is a limiter on the maximum engine speed allowed when the variable cams are in Spool mode.  Increasing this value to allow the variable cams to command significant overlap greatly benefits the amount of boost that can be generated while stationary – in testing, we were able to build up to 15psi with this limiter increased.  VCT Spool mode triggering conditions are not fully understood at this time, but appear to use a delta between Air Charge and Air Charge Desired – when the difference is large enough, and engine speed is below this RPM limit, the cams are commanded into the relative positions calibrated in the Int./Exh. Camshaft Desired Angle (Spool) tables.  Note that in the LC Load Target table that load target values at all engine speeds and zero MPH rear wheel speed, load target is set to 190.

 


Additional Launch Control Limiters/Control

Launching the car properly isn’t just about making power at the line and sending it. It also involves staying in control of the car and optimizing traction. To that end we added a few other limits when under launch control.

Wheel Speed Max/Min

During the use of launch control, reducing power etc. based on wheelspeed can be very helpful as it acts a bit like traction control. However equally important is when you exit launch control and unleash the full power of the engine. As such, timing when the car exits launch control via your Wheel Speed Max can help make sure that once your car has started on it’s way, you are no longer reducing available power. In this way after the car gets up to a speed where traction is no longer an issue you can safely increase power.

Launch Control Load Scaled Max

This puts a cap on the amount of load the car is allowed to target when under boost control. That way when making adjustments at the track via the Accessports adjustments menu, you can make sure you don’t actually go a little too spicy.

Clutch Brake Bypass Switch

In the event that for a mechanical reason you aren’t able to use the factory clutch pedal to engage launch control, it will bypass the check that looks at the clutch pedal before activating launch control. Keep in mind that this means whenever the other factors (safety tables, wheel speed etc.) are within the proper range for the system to activate launch control, it will activate.

 


Safety Tables

A few tables are built in to limit the use of launch control to situations where it is safe for the vehicle and user. These can be custom tuned or also disabled in the Launch Control Safety Switches folder if you like to live dangerously.

  • Coolant Temperature Min/Max: Sets a temperature range where launch control can be activated to prevent it from being done with the engine is still warming up or is too hot

  • Engine Oil Temperature Min/Max: Sets a temperature range where launch control can be activated to prevent it from being done with the engine is still warming up or is too hot

  • Exhaust Gas Temperature Max: Requires the exhaust gas temperature to be lower than this value in order to operate launch control. Makes sure the turbo/catalytic converter etc. don’t overheat (danger to manifold)

  • Launch Control Time Out: Limits the duration of how long the car can sit in space with launch control active

  • Steering Wheel Angle Max: Requires your steering wheel to be within X degrees of centered when using launch control. Helps make sure the car doesn’t activate launch control in an unstable manner.


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