Coolant offset: I can't seem to find a direct answer for ECU modes

[EfiniX]

What I've got:
car idles warm at 190-196
car runs/races up to 209

What I've gleaned from other posts:
Closed loop starts after 190
FT learning after 197

What I think I should do:
set coolant offset to 10 or more

Logic:
If I understand what the coolant offset does, a setting of 10 will effectively drop the closed-loop and fuel-trim coolant thresholds by 10 degrees, effectively allowing me to enter closed loop at 180 and FT learning at 187.

Do I have this right???

 

[prove_it]

Yes, but on a 1G the heating will still happen. Fans are not affected. FWIW, I ran the 180 stat with 60/40 coolant and water wetter, and never had to mess with coolant offset. ECM would still run closed loop.

 

[Fiascoxl]

Those temps are pretty close to stock. Remember timing starts to get pulled at 206 degrees, so if you change your coolant offset you will also lower your high temp timing threshold as well.

edit: Haha, I just realized that lowering the coolant temp offset will keep you from that threshold. Disregard.

 

[turbowop]

If you're worried about the higher racing temps, then install a 180F tstat and then use ECMlink to turn the fans on at a lower temp via one of the programmable outputs. Just run a wire to the fan relay ground and the output can be set to pull the relay to ground early at whatever temp you set it up for in 'link.

 

[EfiniX]

Nah, 209° on a 100° day is fine. More concerned about running cool enough to cause issues with LTFT's and closed-loop operation.

 

[prove_it]

Not going to happen. Like I said, I ran a 180 and still saw 200*. The rating is just when the thermo opens, not the hottest the engine will run.

The 4G63 makes lots of heat, especially under boost. You might not always trip closed loop from a cold start up until you drive it and get some load on it, but it will cycle, also once in closed loop, it tends to stay there while driving.

If anything, since you have link, just make sure your open loop tables and airflow corrections are dead on. You won't see much loss in fuel mileage if it's sticking in open loop.

I always tune in open loop and get the low end of the tables dialed in so if it's ever not cycling closed loop for some dumb reason, then fuel is still in the range of Stoich anyway. Then I allow closed loop operation.

 

[EfiniX]

Well great.

At this point, cooling-wise, I've got a 180* thermometer, scirocco radiator, and two 12" fans. And thanks for the clarification on the thermostat. I get what the rating means, but in doing some research on the radiator work and subsequent cooling odds and ends, I was astonished at how many people thought that the thermo rating somehow = engine heat. It's just when the water starts to flow. The rest comes down to the efficiency of your radiator, water mix, airflow, fans, and how much heat is getting trapped under the hood.

To your point, specifically, I dropped my offset from 15* to 3*, fixing an errant adjustment I had made before based on the 2g coolant data. Turns out 2g's expect to run much cooler than 1g's

(From ECMLink)

1G Learn mode (all must be true)
Coolant temp >= 190F
Intake air temp < 123F
Baro >= 22.9 inHg
Baro &#8656; 31.6 inHg

2G Learn mode (all must be true)
Coolant temp >= 180F
Intake air temp < 133F
Baro >= 22.9 inHg
Baro &#8656; 31.6 inHg

I got it backwards. Adjusting the offset gave me some timing back and the car actually jumped today when I hit the throttle and gave me the "kick" I knew I was missing.

 

[prove_it]

2G runs cooler due to the OEM equipped 180 stat. I think mitsu realized that 210 degree normal temps was a bit high.

 

[EfiniX]

In anycase, with a 180F thermo and all the great custom work EHMotorsports did with my radiator and cooling system, the car is running where I want it to run (196 on the drive in to work today), and is moving the way I expect it to move.

Now onto the broken door lock solenoid, leaking fuel pump hangar, leaking oil filter housing, oil pressure spring adjustment, frame work, leaking steering rack, failing wheel bearing, and warped FP racing manifold...

 

[GSTwithPSI]

What was the final configuration you and EH came up with for your cooling system?

 

[EfiniX]

well we ditched the shroud idea when it became apparent that we couldn't get the fan coverage that we wanted. So right now, I"ve got a scirocco radiator, 180F thermostat, and two 12" fans. One is pulling, and one is pushing since we ran out of space and clearance on the back of the radiator.

Works like a champ!