Closed Loop / Open Loop

[CarloL]

Hi

Just out of curiosity , with the advancements in hardware , would an M1 still run Open loop under WOT (Wide Open Throttle) or can the ECU react fast enough to run Closed Loop?

thanks

[Stephen Dean]

Hi,

We always recommend that the engine is tuned properly and that all of the configuration is correct (correct injector calibrations, charge cooling and fuel film done) rather than relying on closed loop to maintain Lambda Aim. If all of this is correct, and the Actual Lambda and Lambda aim variance is within a few %, then CLL will work through the whole engine speed range without issues. One of the main configuration settings that people miss when setting up CLL is the Fuel Closed Loop Period, this is a table that informs the M1 how long to delay will be between a requested change in the injector pulse width is made, and it being read by the lambda sensor. If this value is incorrect, then it is possible for the CLL system to become unstable.

[Suprafied]

Hi,

We always recommend that the engine is tuned properly and that all of the configuration is correct (correct injector calibrations, charge cooling and fuel film done) rather than relying on closed loop to maintain Lambda Aim. If all of this is correct, and the Actual Lambda and Lambda aim variance is within a few %, then CLL will work through the whole engine speed range without issues. One of the main configuration settings that people miss when setting up CLL is the Fuel Closed Loop Period, this is a table that informs the M1 how long to delay will be between a requested change in the injector pulse width is made, and it being read by the lambda sensor. If this value is incorrect, then it is possible for the CLL system to become unstable.

One question with regards to order of setup, should the CLL settings (period table, etc.) be finalized or close to before fine tuning primary fuel film settings?

Just wondering if an incorrect order between these two features could result in challenges or repeatable data with tuning fuel film.

DP

[chuckk]

Hi,

I always do all of the fuel tuning with closed loop turned off. That means tuning the fuel film model with the closed loop not active.