Hi,
I am calibrating an N54 PnP S7+ set up. I am finding the DI asynchronous pump set up needs fairly elaborate PWM control. The way the base strategy is set up is basically a generic CLPWM (clPWM01 in the output) controlling DI pump duties against fuelduty1.
The system appears to have non-linearities related to temperature and required DI pump duties independent of calculated fuelfinal1 and these have been successfully dealt with using CMs (ECT v run time acting as adder on CLPWM01 Di output). From cold start I can now have clean stable DIP without the integrator winding up by leaning on P / I and while also having a moderate P term that does not oscillate the pressure under load.
One area that I'm looking at is large DIP variations associated with trqfuelsev requests (gear cut/traction/rev limit). Such requests that happen under load throws off DIP. One would think fuelduty1 would account for these but not sufficiently in may case. Even if I use fuelfinal1 instead it still does not reflect how much duty reduction is needed on the DI pump duty under trqfuelsev situations. However, with trqfuelsev used for ORFC with low demand or closed throttle, the DI pump duty reduction required is larger than under load otherwise DIP overshoots significantly.
I have addressed this with two CMs;
CM311 for for DI pump duty adder using trqfuelsev v RPM (reduced DI duty), this CM also feeds another DI adder map CM304 that takes the CM311 output against TPS. Basically, when throttle open and trqfuelsev has a value (gear cut, traction, revlimit, ALS etc), it takes out some DI pump duty, however when ORFC is active and TPS closed, it takes out even more.
The strategy took some time to calibrate but works surprisingly well and stops massive overshoot of DI pressure when letting off a run and keeps a nice DI pressure when trqfuelsev is active. I can now run the car and enjoy traction cuts, gear shift cuts, launch control etc and DIP remains well behaved.
My query: One thing I have found is that if you log fuel consump vol rate (fuelconsvolrate) it looks to be a far more reliable indication of fuel use when under trqfuelsev versus fuelfinal1 or fuelduty1. It shows a significant variability during trqfuelsev operation and Ideally I would like to be able to map DI pump duties against this, or at least a CM against it to simply my 'nested' CM's. Is there is some way I can turn this fuelconsvol calculated variable into something I can calibrate against?? it does not appear in the CM variable list
Cheers.
Using Fuel Consumption Volume Rate in strategies?
Re: Using Fuel Consumption Volume Rate in strategies?
That's quite an interesting read. I have also had issues with huge spikes in DIP (specifically on VAG engines) when rapidly closing the throttle. Have not tried too hard to solve it until recently, but now have an older engine where the spikes go over the max "safe" pressure of the sensor, so that needs some sorting!
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Re: Using Fuel Consumption Volume Rate in strategies?
Fuel consumption volume rate, or fuel economy, is a measure of how efficiently a vehicle uses fuel to travel a certain distance. By focusing on improving fuel economy, drivers and fleet managers can reduce fuel costs, slope gamedecrease emissions, and increase the overall sustainability of their vehicles.
Re: Using Fuel Consumption Volume Rate in strategies?
Encouraging drivers to adopt eco-friendly driving habits, such as smooth acceleration and braking, maintaining steady speeds, and reducing idling time, can significantly improve fuel consumption volume rate and overall fuel efficiency. magic tiles 3
Re: Using Fuel Consumption Volume Rate in strategies?
Truly friendly driving habits should be applied more widely and more commonly every daysnow rider 3d
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Re: Using Fuel Consumption Volume Rate in strategies?
Using custom maps (CMs) to adjust DI pump duties based on various inputs such as temperature, throttle position, and torque fuel requests is a sophisticated approach.Slowie wrote: ↑Thu Jan 26, 2023 7:09 pm That's quite an interesting read. I have also had issues with huge spikes in DIP (specifically on VAG engines) when rapidly closing the throttle. Have not tried too hard to solve it until recently, but now have an older fnaf engine where the spikes go over the max "safe" pressure of the sensor, so that needs some sorting!