Only reason he's doing it is so you dont notice the sudden drop when the PCM switches from 90-100kpa. When I had 1bar I had my timing stock until the 100kpa range then it pulled 10 degrees, it was so noticable I thought something was wrong, and the fuel was the same way. This is the main reason I switched to 2bar to take advantage of all the extra cells that are being "dumbed" down to lower timing (plus richer fueling) when it's not needed.

 

Its not complicated. Its easy. If you do any street driving at all I would not use an open loop tune period. Who wants to spend all their time tweaking all those open loop tables and VE tables? Only reason I can see to use open loop is if you have a gigantic cam that wont idle or surges at 14.7.

 

Even that doesnt matter, you can change the stoichiometric target.
Closed loop is a very very very good thing.

 

How much timing could you get away with before the alky?

 

How do you change the stoichiometric target with Tunercat? Is this a new update?

22-24 but I was only pushing 10psi with a P1SC back then. I've never tried running 15psi without alky.

 

Were you pulling 1 degree per # when you had it set to 22-24 degrees?

 

I thought the reason anyone uses open loop only is because they have a gigantic cam that causes problems with 02 sensors.

2 bar tune works great with 02's, you can run closed loop if your cam allows it.

 

Haven't personally tested it yet.

Fast O2 Rich/Lean Threshold Vs. CL Mode

300mV should give about 16:1 CL AFR
and 800mV about 13.4 AFR

The parameters must mach up to the CL Mode Value Vs. Airflow table. So for example 300 in the 0, 16, and 32 column should ensure 16:1 under cruising airflow conditions.

My car is down, someone care to test this?

 

No I didn't have a MSDBTM then. I was putting 22-24 in the 100kpa column with no box and no alky. That P1SC was really weak and I had pretty good IAT's because of the intercooler so I was able to get away with a little more timing than most. Not trying to throw stones but I'll bet your IAT's with the turbo will be a bit higher and the potential for knock will be greater with fast onset of boost.

Yes, I may try a closed loop 2 bar when I get back from Iraq and have some time to tune.

I've actually tried bumping those table down to 350 mv and it did not affect the 14.7 AFR. Don't know why because in theory it should. I think those tables are mainly for fine tuning the O2 sensors. Somebody correct me if I'm wrong.

 

They have to match up to the other table CL Mode Vs. Airflow, so it'll only work at the associated MAF airflow readings... I think

 

Good info dude. i agree, my IAT's will probably be higher for sure. thanks for the info!

 

IATs with my turbo are about 15degrees above ambient @ full bewst (7psi), but I've got a pretty big intercooler..?

 

This is what I was running after I reconfigured my MS. I have not made it to the dyno to tweak anything yet. Y axis is map in kpa.

 

Yeah back when i was figuring out my base tune last year , i had made a smooth transition from 80+kpa. Then i had a guy look at the tune and found aloot more power leaving them stock under the 100kpa column. Now i have open loop 2bar and love it.

 

Mine shows -

RPM____4000_4500_5000_5500_6000_6500_7000


80 KPA_ 38 _ 38 _ 38 _ 38 _ 38 _ 38 _ 41


85 KPA_ 37 _ 37 _ 37 _ 37 _ 37 _ 37 _ 40


90 KPA_ 36 _ 36 _ 36 _ 36 _ 36 _ 36 _ 36


95 KPA_ 27 _ 27 _ 27 _ 26 _ 26 _ 26 _ 26


100 KPA_ 22 _ 22 _ 22 _ 22 _ 21 _ 21 _ 21