CLT dependent Rev limiter (fuel cut)

[ZoLtaR]

I was wondering if something like this is possible with VEMS. I know that MPower BMWs have such an option. As coolant temp increases , you can rev the engine higer. This is a great option to protect yourself against "idiots" who likes to torture cold engines.

Is it possible to add such an option to future firmware releases? I mean very simple table with coolant value vs rpm limit value.

[GintsK]

If you do not use Launch or ALS it can be done now. But in two steps. Just use one of Misc outputs to activate Launch or ALS input and configure it accordantly. 

In 1.1.89 I see also function called Launchtrim. Seems it stand for variable rpms! Then also step-less configuration is possible: connect CLT signal trace to one of the analogue inputs and configure anytrim as launchrim on this chanel. But then launch should be configured as always active.

Gints

[ZoLtaR]

Thanks, but I am currently using launch control. So no possibility to have it permanently "on".

[Jamo]

What an excellent idea

[GintsK]

Your CLT level also can switch over to B config and do limiting there. You do not need working launch on cold or overheated engine. Right?

[ZoLtaR]

Sure, we don't need launch when warming up the engine. How to tell VEMS to switch tables when CLT readings reach some value?

[GintsK]

By misc output connected to on/off (means pullup equipped) input.

[ZoLtaR]

You could somehow expand your mind? Switching A/B maps are realised the same way like launch/als ? I mean via switching analog inputs to ground?

Sorry, I don't get it how to do this

[rob@vems.co.uk]

It would make sense to have an overheating rev limiter too.

[GintsK]

You could somehow expand your mind? Switching A/B maps are realised the same way like launch/als ? I mean via switching analog inputs to ground?

Sorry, I don't get it how to do this

Yes. We have 4 pullup equipped inputs inside unit. Misc outputs on each config should be configured little differently for some hysteresis.
Simple way then is just make rev limit lower on config B. Advanced way - config B with variable launch limiter adjusted by CLT signal voltage. In 1.1.89 has table for anytrim: ADC input voltage vs limit rpm.

Gints

[gunni]

Or simply add another rev limit to the Anytrim functions based on coolant temp directly.

The curve would be coolant temp and the adjustment could be added or removed engine speed from the base rev limit, should be simple to achieve with a firmware update.

[ZoLtaR]

Switching maps it's a bit complicated.

Can't it be done with new firmware? I mean I would like to have just option in VemsTune with a table coolant temp vs rpm limit with simple enable/disable option.

[Jamo]

Switching maps it's a bit complicated.

Can't it be done with new firmware? I mean I would like to have just option in VemsTune with a table coolant temp vs rpm limit with simple enable/disable option.

I second that

[Ignitec]

I saw clt dependent rev limiter on megasquirt about 2-3 years ago. It was piece of cake to configure, and worked well. It might be interesting to implement in some future firmware. Than we could make full-idiot-proof car

[GintsK]

My way is overflood engine with applying lot of WU again

Last year one guy overheated engine so severe that red-coloured valve cover becomes more grey than red, temperature sensors plastic was melted, but engine internals was cooled fairly well with gasoline. Head was usable even with no resurfacing. One piston has broken (not melted) ringland - and just because no knock control. Other three was perfect!
And yes!- it was circuit racing! Ok - on wet...