Temp question (Topic Split)

[Italian LX]

Originally Posted by 93Cobra#2771

Do a dyno tune and raise the FP to get more fuel and get your a/f just right. Then go back in a few months, don't touch anything, and more times than not, your a/f will be leaner than what it was. Kinda scary, huh?

This is why DSP recommends a long-term "street tune" on a car in addition to any dyno tune sessions.

[QWKSNKE]

yeah Brian is right,

While it is something that could not be done in a day, street tuning is very important. Actually did my street tune before my car was put on the dyno. Reason being, is that if you do the dyno tune first, then have to make adjustments during street tuning, it can/will throw your WOT all out the window.

With my particular application we had probably around 6-8 hrs just in street tune. While that sounds like a lot, it set the car up where after 4 pulls on the dyno we were done. (which ='s cheaper $$$ )

[Sendero]

I have found that EEC-V cars are more reliant on the Adaptive Strategy (AS) for Short/Long term fuel trim AND WOT fuel. This is experienced backed up with two seperate dyno sessions where the car went in to "limp mode" when making changes to OL Fuel Tables with AS enabled.

I'm beginning to think the recommendation to leave Adaptive Strategy enabled while doing your tuning is wrong.

[Sendero]

Originally Posted by Sendero

Mine goes CL on a time limit. The engine temp is only used for the ECT adders for spark and fuel.

Figured I would quote myself since everyone discussing CL Temperature operation missed it.

Datalogged this morning to verify my thoughts. It took roughly 360 seconds for the O2's to begin switching. This means it took my car 6 minutes of idleing before it started the Closed Loop control. Engine Temp at that time was 133*, well below the "Hot Start" ECT Table of 150*. Your car WILL go into closed loop operation well below the "percieved" thermostat limit. BUT your EEC can keep the car in "start up mode" fuel tables if it doesn't reach a certain temperature.

Like with my strategy, anything below 56* it uses a mulitplier of the A/F start up mode table. Between 56* and 150* it uses just the table by itself. Above 150*, it assumes the car is warm and ready for fuel_OL_stabilzed settings.

[93Cobra#2771]

I'm beginning to think the recommendation to leave Adaptive Strategy enabled while doing your tuning is wrong.

I don't remember how, but I THINK you can disable specific cells in the adaptive strategy tables to kill adaptive control at WOT. You'll have to do some digging on the tweecer forum or in the tweecer yahoo group to confirm, though.

[QWKSNKE]

Originally Posted by Sendero

Figured I would quote myself since everyone discussing CL Temperature operation missed it.

Datalogged this morning to verify my thoughts. It took roughly 360 seconds for the O2's to begin switching. This means it took my car 6 minutes of idleing before it started the Closed Loop control. Engine Temp at that time was 133*, well below the "Hot Start" ECT Table of 150*. Your car WILL go into closed loop operation well below the "percieved" thermostat limit. BUT your EEC can keep the car in "start up mode" fuel tables if it doesn't reach a certain temperature.

Like with my strategy, anything below 56* it uses a mulitplier of the A/F start up mode table. Between 56* and 150* it uses just the table by itself. Above 150*, it assumes the car is warm and ready for fuel_OL_stabilzed settings.

You guys and your freaking EEC-V's

[Sendero]

Originally Posted by 93Cobra#2771

I don't remember how, but I THINK you can disable specific cells in the adaptive strategy tables to kill adaptive control at WOT. You'll have to do some digging on the tweecer forum or in the tweecer yahoo group to confirm, though.

Yeah, its the fuel_adaptive_update_rate table. You can disable the upper load settings to disable Adaptive at WOT. I was told NOT to do this for tuning by Chris Mureen. But, I believe that this is not an entirely accurate statement and here's why.

Adaptive Strategy is there so the EEC can "learn" and make small corrections based on engine and eviromental conditions. So when you are "tuning" you are basically tuning for that set of conditions which could be totally wrong in time. I believe Adaptive Strategy, while it has its usefulness, is used by the engineers as a "horseshoe" fix for tuning an entire fleet of vehicles. All they have to do it get close to desired tuning effect and let Adaptive do the rest.

As soon as I free up some time to play with the TwEECer again I am going to try some things. First, I am going to disable Adaptive Strategy totally. This ensures that the computer won't counter act any tuning changes that I make. Then using EEC_Analyzer I am going to start dialing in my fuel tables and transfer values. Once I get my KAMRFx's and LAMBSE to the desired values, THEN I will turn Adaptive back on. My thinking is that tuning the car with Adaptive off will get me very close to the optimal fuel control that my setup will require. Then with Adaptive back in control, it can make the small corrects it needs to ensure the best performance. I could cut this time down with two visits to the dyno. One trip would be for tuning only with Adaptive turned off. After that tuning is done, I would turn adaptive back on and drive it for a couple of weeks. Then its back to the dyno to verify that the "tune" is still optimal.

[Italian LX]

Oh no, here comes the headache.

[TheJeanyus]

[Italian LX]

Originally Posted by TheJeanyus

Maybe that smiley should be called :tweecer: