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Re: Launch Control Settings

Posted: Mon May 20, 2019 11:15 am
by Grabla66
I'll put some screen shots up when I've had time to go through all the settings this week.

Is there a diagram that explains all the settings that contribute to launch rpm and launch exit speeds?

Re: Launch Control Settings

Posted: Wed May 22, 2019 6:20 am
by Grabla66
Panic over.

I've now looked at the data from the last pair of runs on Sunday, and before I went out, I'd raised the upper base engine rpm from 6050 to 6500 at the highest speed breakpoint of 45mph. (It was previously set to 6050rpm which equals 40.5mph in 1st gear so it couldnt have reached 45mph at those revs)

The data from the last two runs shows that the engine rpm was allowed to rise above 6000rpm during launch, the automatic gearshift occurred at 6000rpm, and PIT/LAUNCH events stopped a fraction over 40mph, so it was all working properly.

Q) What key do I need to press to get the data to appear inset in the graphs, like it shows on Ryans's Syvecs training videos? (see attachment)

Re: Launch Control Settings

Posted: Wed May 22, 2019 6:22 pm
by stevieturbo
Options, All Toggle Options, Show items in graph.

Re: Launch Control Settings

Posted: Thu May 23, 2019 12:00 am
by Grabla66
Thanks I'd never have found that.

Re: Launch Control Settings

Posted: Mon Apr 18, 2022 12:34 am
by johnfelstead
johnfelstead wrote: Mon Feb 11, 2019 9:45 am 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.
Just as a update on this. Although the firmware release says the function works in 1.84 and 1.100, neither worked in practice.

The issue was fixed in firmware 1.103, so i now have a working flat shift and launch control using the clutch switch as the trigger for both.

It's made a huge difference to the launch control, using speed to trigger the hold timer simply didn't work properly due to the lag in the speed signal being long enough it effectively hit a limiter during the initial stage of launch when it thought the car was stationary but was actually trying to accelerate past the launch rpm point.

The car really is a quick thing off the line now. :shock:

Re: Launch Control Settings

Posted: Mon Apr 18, 2022 9:22 am
by stevieturbo
Do you transfer from staged launch, to normal launch via the clutch switch then ?

I presume that also needs some adjusting or fine tuning for the transition ?

I found that using wheel speeds...it was very easy for it to bog in when using staged launch. And around the time that feature came to be...also noticed the same with quite a few other cars I'd seen in videos with them bogging on the line.

It seems the stage needs to be de-activated very quickly.

Re: Launch Control Settings

Posted: Mon Apr 18, 2022 1:44 pm
by johnfelstead
Hi Stevie,

I just use the stage exit at hold timer set to 0.01s, so it switches out of stage mode as soon as the clutch switch is triggered and the hold timer starts to count down.

There is effectively a small lag time from the moment the clutch starts to bite to the moment the switch is changing state because the switch is at the top of the pedal stroke to enable the flat shifting to work properly, but that doesn't introduce any issues to the launch, when triggering off exit speed only it was bogging as it tried to stop the engine revs and boost going over targets required when stationary.

To make the launch strategy perfect, you really want the launch switch activating at the clutch bite point further down the pedal, but as i share the switch for both launch and gear cut strategy, it needs to be at the top, otherwise the torque would be introduced too soon on flat shifts and you would get some clutch slip, which will wear the clutch out sooner.

What used to happen was the hold timer wouldn't start until well into the launch, the car would stop accelerating as you describe, then it would pick up again. It was loosing me a lot of time if you compare the launches.

I'm using an organic clutch as it's my daily driver, so don't launch the car with huge torque, only 1 BAR boost, but it's spinning up all 4 tyres and pulling 1.1G on road tyres on normal tarmac now. It could be quicker if i had a better clutch and was prepared to risk the drivetrain. It's quite impressive for a full weight road car with stock transmition and an organic clutch. 0-60 is 3.7s and 1/4 mile is 12.1s, anyone who knows how slow my shifts are would see that as pretty good for a proper road car, with me onboard it's weighing 1560Kg and has about 460BHP/lbft on pump fuel. Tyres are 235/40x17 Michelin Pilot Sport 4, just a decent normal road tyre.

The trace below is from my AIM Solo GPS logging doing a standing 1/4 mile on average grip tarmac and then straight into a flying 250 metres. The most I've seen is 1.19G on a fairly rough tarmac surface. I've not launched the car on a high grip surface, but limit is my clutch anyway.
standing quarter and flying.png
standing quarter and flying.png (112.23 KiB) Viewed 12262 times

Re: Launch Control Settings

Posted: Mon Apr 18, 2022 1:50 pm
by TimH
johnfelstead wrote: Mon Apr 18, 2022 1:44 pm To make the launch strategy perfect, you really want the launch switch activating at the clutch bite point further down the pedal, but as i share the switch for both launch and gear cut strategy, it needs to be at the top, otherwise the torque would be introduced too soon on flat shifts and you would get some clutch slip, which will wear the clutch out sooner.
How about a linear pot connected to the clutch pedal - would allow different triggers to be set for different pedal stages?

Or maybe a clutch pressure sensor might give sufficiently different readings at the bite and top/release points?

Just random thoughts!!

Re: Launch Control Settings

Posted: Mon Apr 18, 2022 1:58 pm
by johnfelstead
I'm not sure how you could use the one analogue sensor to trigger the two different functions, but i would expect a pressure sensor would be ideal for using as a variable trigger point on something like a clutch. You would need to do some testing to map the line pressure to the clutch clamping rate at the bite point, but that shouldn't be too difficult.

Re: Launch Control Settings

Posted: Mon Apr 18, 2022 2:00 pm
by TimH
johnfelstead wrote: Mon Apr 18, 2022 1:58 pm I'm not sure how you could use the one analogue sensor to trigger the two different functions, but i would expect a pressure sensor would be ideal for using as a variable trigger point on something like a clutch. You would need to do some testing to map the line pressure to the clutch clamping rate at the bite point, but that shouldn't be too difficult.
Of course - I was forgetting it was wired to one input, essentially as an on/off.

I'll go back to sleep :mrgreen: