Launch Control Activation

Hi,

I have yet to test this on my vehicle as I want to get a better idea of how it works before I begin testing.

With Launch Control in M1, is my understanding correct?

1. Driver holds down Launch button (or toggles?)

2. If conditions are met (vehicle speed, etc), driver increases throttle pedal PAST the entry % to enter Launch Control mode.

3. When driver decreases pedal under the exit %, it launches?

Is that a correct understanding? Or is the launch initiated when the launch switch is released (or taken out of activation position)?

Thanks,

Ryan

What Firmware are you using? There are some variances in the operation of the Launch Control depending on the Package.

You do not need to have a dedicated Launch button, it is possible to have Launch activate if the Activate conditions are met. If Throttle Pedal Entry is exceeded and Vehicle Speed is below the minimum set, then Launch will activate and stay active until the vehicle speed exceeds the Maximum value set, ot if Throttle Pedal drop below the Launch Ext Throttle Pedal value.

From the GPR Help.

Launch

For this system to activate Driver Launch Switch must be On. If no switch is present Driver Launch Switch Mapping Default must be set to On.

This system aids initial take-off by means of ignition retard, engine speed limiting, electronic throttle control and boost aim control. It also provides fuel volume trimming to assist exhaust cooling.

Engine speed limiting during launch uses the Engine Speed table and Engine Speed Margin . The primary means of control is ignition retard.

While engine speed is above launch Engine Speed, the Ignition Timing Limit Advance system attempts to control engine speed using closed loop control of ignition timing. If Engine Speed exceeds (launch Engine Speed + Engine Speed Margin), a hard limit (ignition cut or/and potentially fuel cut) is applied. This allows turbocharged engines to develop boost pressure prior to launch.

The activation state of the launch system is reported by State and further information about why launch is inactive is reported by Diagnostic.

The following conditions must all be met for launch to activate:

Mode must be Enabled.Exhaust Temperature must be less than Activate Exhaust Temperature. If Activate Exhaust Temperature is set to 0 this setting is ignored.Coolant Temperature must be less than Activate Coolant Temperature. If Activate Coolant Temperature is set to 0 this setting is ignored.Vehicle Speed must be less than minimum vehicle speed axis site on the Engine Speed table. This condition is ignored if the vehicle speed axis is not enabled.Throttle Pedal must be greater than Entry Throttle Pedal.Launch will exit if any of the following conditions are met:

The engine is stopped.Vehicle speed axis of the Engine Speed table is enabled and Vehicle Speed exceeds the maximum axis site value.Throttle Pedal is less than Exit Throttle Pedal.Exhaust Temperature exceeds Activate Exhaust Temperature. If Activate Exhaust Temperature is set to 0 this setting is ignored.Coolant Temperature exceeds Activate Coolant Temperature. If Activate Coolant Temperature is set to 0 this setting is ignored.

I'm using GPRP, and I'm curious as to how the launch actually activates.

The above description is complete.

The key condition is that the vehicle be stopped, and Launch Control is enabled. You depress the clutch, and step on the throttle pedal past the Entry Throttle Pedal (Usually going to full throttle). The Launch system holds the engine speed found in Engine Speed Table for 0 mph.

When you release the clutch the Launch system controls the engine speed per the Engine Speed table , Throttle Limit table, and Boost Aim table until any of the exit conditions are met. I suggest using the Veh Speed / Estimate axis on each of these tables and tuning that to get the maximum vehicle acceleration.

I am also trying to understand this on a GPRP platform, as we have no method to manually engage the clutch. The OEM process was somewhat similar, push a button to request launch mode, pull both paddles toward the driver, push throttle to exceed set point. To launch we released both paddles. I’m not looking at my M1 package right now, but hoping there is a similar feature we are able to set up.

Tim, GPRP isn't going to work with that. But it also doesn't have clutch control -- What is the car, and what ECU to you currently have? If It's a MoTeC, then what firmware package is it using?

Hi David, working on a Honda Talon which is a 4 wheel drive off-road buggy. It is powered by a 2 cylinder 1000 cc motor with individual throttle bodies, runs a dual clutch transmission, with a sub-transmission providing reverse and hi/low gear ranges. MoTeC M150 with Firmware from Jackson racing.

Perhaps I am mistaken, but I have been operating under the understanding it is GPRP with the “P” being the designation for paddle shift capabilities. This firmware does indeed have dual clutch hydraulic control of the clutches.

Your firmware is whatever Jackson Racing calls it, but not GPRP. It obviously has capabilities beyond the MoTeC GPR-P package. GPRP generally stands for 'General Purpose - Racing - Paddle Shift'.

If you will upload a copy of your package, we can take a look and help you understand how Launch Control works in that package. In M1 Tune, use Open Package, and select the package then use the "Export" icon to create an archive file. That can be uploaded here (or if it can't then compress it into a ZIP file and upload that).

Hi David, thank-you for the follow up. I've attached one of the early versions of the project, this is an original that they sent me with me making changes for the injectors I am running and fuel type to E85.

With the driver using the the OEM Honda ECU, they would press the launch control button and wait for the launch light to display on the dash, at that point the driver would pull both paddles in and then depress the throttle pedal to bring up rpm's. When it was time to launch the driver would release both paddles and the car would launch.

My thoughts so far is to try to figure out how to create a command that causes the clutch(s) to enter released state when both paddles are pulled, then (easiest) enter "engaged" when they are released. The M1 launch control could handle the rest just like normal once the clutch enters the engaged phase. Without testing, the other thought I have is perhaps have it enter the "takeup" phase where i am more able to control the rate of engagement of the clutch.

Tim, Your Firmware is "RNT Xtreme Honda Talon (M150)" developed by RN Technologies -- support should come from support@powertune.com.au

Looking at your package, I suggest starting with an All Calibrate tab, then search for Launch. This starts with a Launch Mode that allows Clutch Activation, Brake Release application -- which I think would be suitable for your use. There is also a Transmission Brake Release option. After that, I would look at the table Launch.Engine Speed.Main table, and enable the "Vehicle Speed Estimate" axis (and probably disable the Driver Launch Aim Switch axis unless you have one fitted).

There is a specific table for Honda Talon DCT Clutch Pressure Control Launch Clutch Pressure Target Main, that you probably need to tune. Unfortunately, there seems to be no F1 Help available, so I guess you need to email the support above to ask (I would ask that they add help so others can benefit as well!).

Good Luck!

Thanks for the reply David. Unfortunately the dealer I got this from was selling it in a beta format and hasn’t been returning emails for a while now, though I will continue to reach out that way. I did reach out to Ryan (support@powertune.com/au) and he let me know that the dealer is the one selling the firmware and support would need to come from there. I’m left feeling this means I need to solve this on my own.

I’m interacting here on the forum to help me brainstorm different path’s I might e able to use to get launch fully functional. What I am not understanding in you comment above is how I can tell the DCT to not allow clutch engagement until the brake is released. I’ve been trying to learn more about setting up the user defined condition switch hoping I can get it to look at something like launch mode active and brake switch on to over ride the clutch engage maps, let off the brake and clutch engages initiating the launch. I’m sure there is an answer in the M150 and M1 tune, it is just me learning how to get it to do what I need it to do.

Normally, I would be able to figure this out from the help. However in the case of this firmware, there zero help regarding the DCT operation, and how those tables interact with how it performs. Is there a factory workshop manual for the Honda Talon that might provide a theory of operation or other clues about how it is expected to work. I just have no experience to share other than to tell you how I would learn about it (using the help, or contacting the firmware identified support asking for specific information needed to tune the package). Perhaps a sample package with Launch setup and working would be available.

My comment about the Launch mode, is that the more recent GPR - based packages allow the Launch Mode to have more than just Not In Use / Active, but allow you to specify what will trigger the launch to start, Clutch Release, Brake Release, or Trans Brake Release. Since you don't have a clutch pedal, I assumed it would be the Brake Release, then something in the Clutch Pressure Target Main would be tuned to get the best possible Launch behavior. Why don't you try getting the various Launch stages to work, and then try changing the values in some of those tables to see if you can figure out what works. There may be other DCT Clutch Pressure tables that give you a clue about what values to put in the tables. If you don't have Level 2 logging for that ECU, I would get that so you can log all the relevant parameters and 50 or 100 hz and see what happens.

I suppose I could see if the launch functions would work either in neutral, or zero out the clutch pressure tables and try that. I’ve gotten pretty comfortable with the DCT tables, theory of operation and such, just not figuring a way to interrupt clutch engagement. The command begins with throttle movement, so as soon as the throttle moves it will go to the “takeup” clutch table and apply the pressure indicated to the 1,3,5 clutch pack. There are really only 2 “takeup” clutch tables, feed forward and clutch pressure. Clutch pressure table has estimated MAP (runnng itb) and RPM’s. There is pressure trim available for oil temperature and also PID. With our desire to race both dirt course and drag racing, I’d ideally like to be able to launch in 1st or second gear.

I was coming to the same conclusion regarding label 2 logging, it may be helpful in this, and there is another strategy I believe it could help me with. I will keep working on idea’s and may bounce some more idea’s here as I continue the journey.

I would expect that Launch Switch would change so that it did didn't release the clutch (i.e. the takeup clutch table), until the brake is released. Only you will be able to test...

I’m going to explore a few different strategies to see if I might not be able to come up with something even better for us than what was OEM. In their launch strategy you couldn’t be on the brake pedal to enter what I believe M1 is calling the launch phase. This made it really difficult on the driver because the staging area would change over the course of the bracket as more and more sand or dirt was displaced resulting in a downward angle at the starting line. It would get significant enough that the car would roll when your released the brakes resulting in a red light. I’m hoping to be able to use both paddles in to initiate, and launch initiate when both paddles are out and use speed to end launch at a really low wheel speed. If we can ignore the brake I’m hoping the driver can initiate clutch engagement and therefore launch even if the brake is still lightly applied so we can focus on the one launch input at the light, and still prevent the car from rolling. As it was the driver had to both release the brake and both paddles all at once to get a clean launch. If the ECU still sensed any brake it wouldn’t launch.

Once I figure out how to prevent the clutch(es) from engaging in staging mode I should be good. I’m going to experiment first with the user defined condition switch configured to respond when both paddles are in and see if I can get the car to enter launch staging and allow rpm increase without engaging the clutch. If you’re interested in follow up I’ll let you know how it goes.