RomRaider

Hello.
Is there a way to launch control on our MS42?
I changed the limiter for 24kph at 3000rpm, but the revs still grow to 6500rpm


Interesting, cut off works:
- only the fifth gear
- over 100 kph

I did not have place for the test but:
Cutting off, stop working after execution:
Use different equipment than neutral or fifth gear
Slow down below 100 kph


However wise man, someone can run the launch control.

The problem is, MS42 uses a much much more simple design of engine speed limitation in code. MS43 is ~ 5times as much code and uses pre-calculated gear ratio whereas mS42 calculates it in the map. So swapping a diff is much easier to account for at MS43 then MS42.

But do you know how that speed axis works or what does it mean in the rev limiter tables? Because it at least doesn't work like in ms41.2 for example. Putting zero to there doesn't make the rev limiter work at stand still.

It obviously doesn´t work as its defined incorrectly the axis is the quotient of current engine speed divided by current vehicle speed.

That makes somewhat sense. Soo we would need to make that axis value bigger to make that limiter value work on lower speeds. Like really big if 0 speed is wanted

Well yeah the "speed axis" doesn't seem to do nothing. And it's not really speed axis as you would assume based on XDF file. But it really is gear based as the ms42 wiki says. It goes from left to right like: gear 5, gear 4 and gears 1-3.

I would guess that getting even some kind of launch control requires code changes and in that case it's better to do it properly based on clutch switch.

Abolutely correct

..interesting...

yes it is possible, you need to change axis for this map the last on the right should be 500, and set your desired rpm, it will limit at that rpm up to 10 km/h

Someone tried to change the axis? I guess we will not do this romraider?

I did. Doesn't work. The axis is not really speed. It's some conversion factor for calculating gear. Gears are 5, 4 and 3 to 1. So if you put the lauch rpm, it uses that for gears 1-3 which is nice...

Yes it does work, you have it wrong then, in ms42 put 500 in last box and 450 in middle box, right box should be your launch rpm

I have another idea for launch control. In fact an ignition cut (retard) launch control by using an Anti-Jerk (AJ) approach.

Been reading the Funktionsbeschreibung_MS42 PDF and found that there is a number of tables that determine when AJ should be activated and how much ignition retard should be applied. Also the gradient for how quickly the ignition is retarded.

Tables I found useful:
- c_n_min_aj (Minimum RPM for AJ to be activated. In this case, our Launch Control RPM)
- c_n_max_aj (Maximum RPM for AJ. Set to permissable value?)
- c_vs_min_aj (Minimum Vehicle Speed for AJ. Set to 0)
- c_vs_max_aj (Maximum Vehicle Speed for AJ. Set to 5)
- c_pvs_grd_min_aj (Throttle body speed for AJ to be activated. 0 because we want it to be active when throttle body speed is 0 at WOT)
- c_tco_min_aj (Minimum temp for AJ to work. Set to the lowest permissable value basically)

Due to the Funktionsbechreibung, "jerk" has to actually be detected before anything happens. I looked at the tables and equations that are actually used for this, but struggled to understand them fully.

I haven't really tried it yet, it's just an idea.

I wonder if it is possible to turn the ignition back so hard that the rpm does not rise above the action AntiJerk
kf_zw_ar__n__lm - antijerk ignition maps

Antijerk reduces ignition timing for little while when pressing throttle quickly. I have no idea how ypu are going to turn that to launch control/2-step.

You would need to activate lower rpm limit by clutch swith (the correct way) or by vss. As said earlier that needs code changes.