RomRaider

Ok thanks Merchgod

I'm pretty sure that when that log was taken the car had been running for atleast 20 minutes. I will try to do it again later while logging the front 02 sensor.

Merchgod-

I took more logs today with the factory 02 as well as my LC-1 using the same rom as posted above. Here are three more instances of the early transition to open loop. The file named 'Early OL 4' is probably the most blatant instance of the early open loop condition.

Note that the LC-1's reading are slightly delayed at these low airflow values as the sensor is in the tailpipe.

Also, the lower end (<-4.30mA) of the front 02 scaling has been modified to be closer to my wideband's readings. I can't think of any issue with doing this but I thought I would point it out.

Any ideas on what is going on would be great.

Thanks again.

what are your mods?

Catless turboback exhaust
catless uppipe
hallman ball & spring mbc
ported factory exhaust mani
port and polished throttle body
ebay top-mount intercooler
one step colder copper plugs

I think that is all engine for engine related mods.

stock intake and injectors? If so, try going back to the stock tip-in enrichment, maf scaling, and front o2 scaling and see if you can recreate it again.

Yes, I still have the stock intake and injectors. I'll try it again after changing those tables back to stock.

also add a/f sensor #1 resistance and run the same log as before but before you change those tables back to stock.

Here are the logs you requested except for I did not change my scaling for the MAF sensor back to stock yet. I am going to have to change my fueling map to do that because with the current fueling and factory MAF scaling I will run too lean.

What does your A/F learning A-D look like? Can you post a learning view SS?

A/F learning stays very close to zero with A fluctuating the most. I have spent a lot of time scaling my factory MAF in both closed loop and open loop so my wideband AFRs match the values requested in the fuel table.

Here is a learning view I just took.

EDIT: Should I consider adding back some delay values and using the other CL/OL delay tables like the maximum throttle table to control the transition?

bill, for a long time i have observed a similar behavior with my 16bit ecu: at low rpms, with low manifold pressure (ie 5psi), the afr will be affected by TPS. part throttle = cl, stoich. wot = ol, and (in my case) around 13.5:1. the crossover seems to be around 60%. load is below that point which would indicate enriched fueling according to the fuel map.

i don't mind it one bit because it works out ok: the richer afrs improve torque down there (i'm usually going wot in 2nd gear coming out of a low speed corner or somesuch), and i don't have to fiddle with the fuel map. but i never did find out where it was coming from, or how to change/set it.

ken

Wouldn't staying at stoich while bogging the car like this help keep EGTs up and spool the turbo faster?

There is a throttle based minimum enrichment (similar to the currently defined for the 32-bit ECU) that I haven't messed with much yet - perhaps this only active at low rpms with the 16-bit ECU. I'll look some more and see if I can come up with anything.

Ok, I took a peek again at this. I was wrong about the front o2 being involved in the final decision for open loop -> it appears that is only the case when there is a failure of the front o2. The final decision, which I missed before, has a number of conditions, any number of which will cause the transition to open loop. One is whether primary enrichment (i.e fuel map) calls for enrichment or not (so my original assumption is correct - as laid out in the OP). This includes the currently defined ECT compensation and an unknown throttle enrichment. I think that throttle enrichment is the key here. I'll mess with it some more to see what's going on. To verify this, casey, I could send you a custom logger defs to log a few of these variables and see if that is the case, if you are game.

in theory, yes. for example, you would be able to see a little shift to the left in a plotted chart of MAP vs RPM.

however, when you factor in the fact that the little extra fuel nets you more torque, thereby causing your rpms to rise faster, thereby causing you to hit your boost threshold a lot sooner in terms of elapsed time, the decision becomes less clear cut.

ie you would be able to see a little shift to the left in a plotted chart of MAP vs TIME.

in my experience you get best results when you tune the car to make the most torque "all motor," ie w/o fancy "spool the turbo up faster" tricks... throttle response is sharper and the car is overall more pleasurable to drive.

hth
ken