I've been on the boards a little while trying to learn as much as I can. I am now getting into learning how to tune myself. Don't worry, I haven't touched my ECU yet, I just wanted to ask a question about (as the title says) partial throttle tuning. I have already downloaded and explored both crome and uberdata and both seem pretty easy to work with. However, since those tables are only referred to in open loop, how exactly do you tune for partial throttle? It just seems that you only have the ability to control to values that are looked up during open loop. I am probably missing something key here, but I cannot figure it out. Thanks.

 

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That helps.


I believe I found my answer though. 2 maps... one for each mode (open & closed), where it will refer to the closed loop map under about 80% throttle.

 

Open loop and closed loop mappings - same exact thing. Forget what you thing you know.

"Part throttle" is just any degree of acceleration that is still in the vacuum range. Just turn off closed loop and start tuning every cell you can hit, you'll get it down fine.

When you turn closed loop back on, make sure you either boost WOT, ro have a script (like in Crome) that allows you to turn off closed loop at a certain manifold pressure. Otherwise the ECU keeps trying to modify mapped values to hit stoich, which is bad bec ause you will run lean under boost.

Uhm, you guys do know the difference between open loop and closed loop, yes?

 

If I say any words you don;t understand, just ask about it. That's the best way to learn. There's a LOT of jargon, and if you are shy about admiting what you don't understand you'll only take ten times as long to learn it.

 

I believe I have a pretty good handle on what it means to be in closed loop vs open loop. Closed being where the ecu will get feedback from the 02 sensor and the MAP, open loop meaning it will look exclusively at the map values. Anything more to that I should know, or is that pretty much the difference?

 

You have it 90%. When too cold according to coolant temo sensor or TPS sends back more tha 4 volts to the ECU, the ECU sticks itself in opne loop.

OBD0 non-B16 ECU are good about staying in open loop if the MAP sensor output changes quick enough. I dunno about OBD0-B16. OBD1 is bad for trying to correct AFRs to stoich then boosting part throttle... Crome, for instance, has a script you can install to lock things in open loop if you exceed (default of, but you can change it) 750 mBar which is 3/4 of atmospheric pressure.

 

Oh yea... before reaching op. temp, I knew it was open. The integra thermostats have a tendancy to break (and they're designed to break in the open position) and it takes forever to heat up. Thanks for clearing it up... does that script come with crome or crome pro?

 

Great info Joseph Davis , so, when the car is cold , it's too in open loop ,right?

 

si.

the scripting you can get with cromepro.