RomRaider

Custom Code testing for Ignition Retard by applying 5V to Pin 80,81,82 is going well. Thanks Peter. I have identified exactly how to independently use each one in code.

So now I want to open up a discussion to the community into how exactly we want to configure these functions. I can do just about anything with this in code, but first wanted to get people's opinions on what they would want.

Here are some of my initial thoughts on it. Feel free to discuss and convince me otherwise.

Terminology
2-Step - I see this is a simple 'Secondary Rev Limiter' which can be user-tunable.
If RPM > X & VS > Y, then retard Z degrees of Ignition Timing. Because the Base Ignition Timing changes with RPM, this will be a variable amount of Ignition Retard applied.

Launch Control - This is a little bit more complex form of '2-Step' and the idea is to have progressively different Ignition Retard at various RPM, Load, and Vehicle Speed/Slip. Not sure if this is needed or if the above mentioned 2-Step function would be adequate. We don't have a true indication of wheel slip between front and rear tires to the ECU so this can't be fully implemented.

No Lift Shift - This will require a small electronic circuit hooked into the clutch switch, so it sends 5V to one of the ECU Pin 80, 81, or 82 when clutch pedal is pressed. Then I can create an RPM by Load table which can be tuned to reduce Ignition Timing as needed. The math for this could also go pretty crazy with lots of input parameters and compensations built in but I want to keep things as simple as possible.

Anyway, just something to start the discussion about this. Feel free to brainstorm and think about what would work best.

I'm new to this but what about using asc data for launch control?

Would you need clutch switch for 2-step and launch control also? Or how the ecu decides when those are needed.

In megasquirt it works well that there is clutch switch and for launch control, the rpm is limited to wanted level when clutch is pressed in and tps is at 10-40% range. (The tps thresold and rpm can be changed. Then you get the 2-step from that if you add ignition cut limiter and enough ignition retard.

Then no shift lift can work from same clutch switch. But now the tps needs to be close to 100% and when clutch is pressed, the rpm is limited to wanted level. And again if you apply ignition cut limiter and ignition retrad to that, you will get flat shift (pops and bangs with turbo to keep boost up).

I have to check what other parametrts there was, but the rpm limit, tps limits and amount of ignition retard are the main ones. And then maybe if ignition cut limiter switch is needed, but I think that could be "on" always.

Clutch switch should not be used for Launch Control. The point of launch control is to control wheel slip while accelerating from a stop. During this, clutch should not be pressed in.

Clutch switch can be used for 2-step rev limiter. But so can a check against Vehicle Speed. If VS < X, then use 2-Step (secondary rev limiter).

FFS will definitely require clutch switch.

Hi guys,

In my MS41 limiters, there is a VSS error secondary limiter. (Engine Speed Limiter (VSS Error))
Do I guess this right: if the Vehicles Speed sensor goes wrong that is the limiter which will be used?
Can I make a "2step" if this signal is interrupted for a short berif of time? (put a button close to the steering wheel, and while pressing it down, it would activate the secondary limiter)
I know this wont make up for a real launch control or a 2step, but for some fun I would try it.

Any advice? From which wheel is the signal coming from? Is there a modul inside the car which is responsible for the VSS signal?
Does any one have any experience with interropting the vss signal? Thanks guys

Don't bother with that. Once a DTC is set for VSS it won't be unset until ECU reset.

Thank you for the reply. Then I guess the only way is to have some sort of 2step is to "upgrade" to ms41.2.

whe Could we have a test definition?

The 2 step idea sounds fantastic, the current rev limiter vs speed sort of works as it sits so any improvement is welcomed.

Could you have the 2 step limiter always on so no modification is required? or it could work by a sequence of turning off/on AC/pedal/other inputs?

It's not just a definition, it's custom code - fullflash. (Could be called MS41.3 maybe ) That's just a technicality tho. Mrf has to answer the question.



It's explained in the first post. 2 step won't require any changes, just mapping and it's always on. Flat shift is going to need its own clutch switch, probably connected to pin 80/81/82.

Yes, it requires lots of code modification and a full flash. I have it mostly completed. Just need to finish writing the extra definitions for it (and lots of other stuff). Work has been extremely busy lately so I haven't had much time after (or the energy) to do it.

I keep planning to work on it every week. And I will keep it on my radar till it's done. Sorry for the wait.

I'm more than willing to test this out on my drift missile, if something's wrong, it's not nearly as big a deal since the car is generally broken anyway.

Hey dear Mrf582,

How does this custom code looks like nowadays?

The code itself (MS41.3 ) is written and I've been running it in my car.

But, the custom definitions for the additional features/tables aren't defined yet so they are using the default values. Once my professional work (Electromechanical Automation Engineering) slows down a bit (huge work project is in the final stages of R&D) I'll have time to write the definitions for the new code and get a few of you to test it.

One of these days I'll list a full list of features that it will come with. I mentioned most of these sporadically through various forum posts but I'll try to compile them all into one thread.

Sorry for the delay.

That sound awesome!

I hope you professional project goes all as expected!

I'd be one happy camper if I am one of the tester

Keep it up