Launch Control Settings

Ryan.g
Syvecs Staff - Caretaker
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Re: Launch Control Settings

Post by Ryan.g »

johnfelstead wrote: Sun Jan 20, 2019 4:19 pm I have just been watching the Syvecs Help video (which are all very helpful) for launch control setup and something doesn't make sense based on how my launch was setup.

My setup uses the following:

launch ramp mode = hold timer
stage parameters = not used, just uses main tables for control
exit speed = 1.6kph
the speed reference is the gearbox speed sensor

Now based on the help video, Ryan says this is too low and should be set high enough to not switch off launch control until a speed you want it to be switched off is attained. So in my case i would think the shift point to 2nd would be a good option to aim for, say 84kmh

The way it was explained to me previously was the hold timer starts once the exit speed is reached, so the exit speed is the start point for the hold timer to start counting, and not the speed launch control switches off.

The question is, who is right? Is launched switched off at exit speed or is the hold timer triggered at exit speed and launch then works until the hold timer has finished its count up to the max value?

What starts the hold timer counting up if its not exit speed?
My Video is Designed to get users on the best strategy, which is using the Staged setup, hence my comment about having the "Exit When Vehicle Speed Exceed" value high for people using the Staged control.

If you are not using the Staged control then you should with a Clutch switch instead of just a Speed Exit... as the Torque Reduction tables need to be different for when 0 Load is applied against the Engines Torque (Stage) compared to when clutch is clamped and the drive-train is in the mix for best results..

The Launch STAGE Exit is based on the Thresholds in the Staged Area for Hold time and Exit Speed. When the launch switch goes to off the Hold Timer would start and this as well as Speed is used for the Exit of Staged Torque Control to Main Tables.

Example of Launch with Staged Attached.
Attachments
1.88 Launch Example.SC
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johnfelstead
Posts: 33
Joined: Wed Jan 29, 2014 12:23 am

Re: Launch Control Settings

Post by johnfelstead »

Thanks Ryan, that makes a lot of sense now.

It looks like using the clutch switch to trigger the launch timer when coming out of STAGE will get around the problem i have with the JDM speed converter signal lag, which would be a big step forward in control. Add in the different tables for off load whilst staged and on load as the clutch is let out and it will be far more tunable.

On my road car I've currently got my clutch switch as the trigger for gear cut flat shifting strategy, but looking at the latest firmware i can now assign that to a clutch switch function and then enable the clutch switch as the gear cut trigger also. Prior to that firmware update i couldn't use the clutch switch for both jobs, so that's also a very useful improvement.

On the TA car i'll setup the STAGE as suggested also, i have a load cell on the shifter on that so can use the more conventional method for the gear cut request.

All very helpful, thanks.
johnfelstead
Posts: 33
Joined: Wed Jan 29, 2014 12:23 am

Re: Launch Control Settings

Post by johnfelstead »

I tried using the clutch switch as a gear cut trigger using the function new to 1.84 and it doesn't work.

I logged this as a problem last year, but forgot i had tried it already when trying something else.

So if i want to use the clutch to trigger the launch timer using the stage tables, i currently cant do that and retain the flat shift functionality, which is far more useful.

I came across this last year when i wanted to implement flat shifting on either the load cell cut input on a sequential gear lever, or if the clutch was pressed, which you might do if there was a problem with a worn dog gear not pulling in.

So the function is there in the 1.84 firmware, it just doesn't work currently.
Grabla66
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Re: Launch Control Settings

Post by Grabla66 »

On the video it shows 11 speed breakpoints, but on my Life F88 ECU it shows I have 15 breakpoints?
Is the number of breakpoints configurable, or is it down to firmware changes that has increased the number of breakpoints since the video was made?

Also if I change the speeds on my 15 breakpoints, when I go back in to the Spin Targets (1-4) they graph is colour coded showing lots of red and amber. Is this a warning, is something wrong with the settings?

Image

Image

Image

Also I'm looking for some usable TC settings, to start as a baseline. Are there any documented anywhere?
stevieturbo
Posts: 1321
Joined: Sun Dec 07, 2008 2:04 pm

Re: Launch Control Settings

Post by stevieturbo »

Number of breakpoints etc are user definable.

The colours simply indicate you've changed the numbers by a particular amount ( when online, not offline )

Once you've saved, D/P they will restore to green ( might need to move away from that screen and back again too )

As for settings.....entirely up to you to decide.

How much wheelspin might you want it to allow under certain circumstances for your car ? Review your logs, your driving style, the sort of g-forces you might encounter....and whether under high g's you might want to allow wheelspin or not, or keep a tight reign on it. Different areas of the track etc.

Presumably under most you wouldnt want to allow a lot of wheelspin given the type of car, it's not really a drifter. But it'll be down to your driving style.

Also view logs when you are accelerating with good grip....I know on my car, I can see as much as 6, 7% difference between F/R wheel speeds when I know there is no wheelspin, which seems odd. Especially with proper low profile stiff sidewall tyres. But it happens every time. So I dont want any controlling action within that range.
Grabla66
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Re: Launch Control Settings

Post by Grabla66 »

Cheers Stevie

Where do I set the number of speed breakpoints?

For the graphs, where spin target 1 is set to 30% at 0.25G at 10MPH, what does that actually mean? And does the gradient slope in the right direction? Is it too aggressive?

I have 11 cal positions for the TC switch, so is it best to use posn 1 to 5 for dry weather settings TC, and 6-10 for wet, and 11 for off?

Sorry for the questions, I like to understand whats going on so I can make better sense of the settings.
stevieturbo
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Re: Launch Control Settings

Post by stevieturbo »

A lot will still depend what options are available to you with the locked ecu.

If you look on the Life site like I said before, they have a fully open and loaded map available so you could compare that, to your own to see if yours is simply inaccessible.
TC settings.jpg
TC settings.jpg (100.33 KiB) Viewed 20381 times
I dont think you can change the actual number of breakpoints here...but probably no real need to anyway. But you can change their values ok.

30% slip at 10mph....is only 13mph driven wheel relative to 10mph undriven. So in percentage terms it seems a lot, in real terms it will allow almost no slip at all before it starts to cut power so could be quiet intrusive ( if TC is even active at only 10mph which is another setting option )

Likewise it will be aiming for this max slip target when your lateral g-force is up to 0.25g ( left or right, doesnt matter )

As for ramps etc....

Would you maybe want some or lots of wheelspin available when cornering at a particular speed ?

Would you maybe want some or lets of wheelspin available when cornering at say 1...1.5....2g ? if the car is capable. I'd suspect the higher the cornering g's and also speed....the more you would want the ecu to keep a tight reign on loss of traction versus slower corners where some wheelspin might help ( ie to allow some sideways action etc )

maybe at low g, straight line in some cases you might want to allow more wheelspin etc Again, review logs of how you drive, where you've had wheelspin, or excessive wheelspin...or where you might deem you might wish to allow more.

Although TC is a deviation from the thread of Launch.
Grabla66
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Re: Launch Control Settings

Post by Grabla66 »

Thanks again, its making sense now.

The deviation from Launch brings me on to the next issue, which is the transition from launch to TC, but I'll try to figure out TC first before I start considering changes for my launch settings.

Thanks for the tip on loading the sample file from the Life site. I found it, loaded it, and its close to what I have now. We still cant change things like the auto gear change, or the engine rpm's that my ECU operates the helmet bleeper at to prompt me to change gear, but its still better than what we had before the relaxation.

My Exit launch speed is set to 10mph. Launch hold time is set to 2.0s, so does that mean it exits launch 2.0s after the car starts accelerating, or does launch exit speed win so it exits launch at 10mph ?
stevieturbo
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Re: Launch Control Settings

Post by stevieturbo »

Paul has already explained some of the details relating to that and the sequence of launch events. Again, logging these and reviewing will help you see what's going on ( if your logging config allows this )

You need to look on your map to see if your launch is time based or speed based with regards to how long the launch "timer" will be active. "Launch ramp mode"

Also, the help files on SCal or LifeCal at bottom of screen explain the functions, and sequence of actions for them.

Although must admit....the help file seems a little contradicting in it's explanation of exit vehicle speed, earlier saying this was a launch de-activation speed....later saying it is now an actual launch control activation speed. ( ie move from stationary to launch hold timer which ramps the launch )

I use speed based on my car, I had this value set to a high speed....ie I expected controlling actions up to this speed, and on logs this does appear to happen with it following and logging a speed/rpm ramp etc, even if launch hold timer stays at zero throughout, actually only starting to count once the high speed value is reached which is at the end of 1st gear anyway.
launch.jpg
launch.jpg (545.44 KiB) Viewed 20369 times
Grabla66
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Re: Launch Control Settings

Post by Grabla66 »

My cars launch ramp mode is Speed, so it must be exiting the LC at 10mph. I'll increase that speed, and I'll also have a think about using the timer instead of vehicle speed, to see if that makes much difference.
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