Hey all,
Car is 2004 USDM EVO8 GSR w/ Tephra V7 installed
I just installed a Mishimoto 66 celsius thermostat and their aluminum radiator.

Now at wide open throttle the car is running rich when the temps are down, its about a half point richer ( 10.9:1 vs 11.5 )

I expected this to occur.

My problem now is, which table controls the WOT fuel trim vs coolant temp?

I was contemplating that I could just tune it out in the main fuel map, but then when the car heats up to stock temp then it would be too lean.

Any help would be greatly appreciated.
If you know the answer and its works I will pay you for your solution via Paypal.

thanks for reading
R Josvai

 

This should do it as long as it's water temps that are affecting your tune.

 

easy solution


put the stock thermosat back in paypal is """"

why the 66 deg stat ???

 

i tried that already and it had no effect

 

put the stock t-stat back on, your half size radiator with a good fan should be good in 100+* weather.. mines holding find on stock t-stat here in the south..

 

i completely understand that the stock T stat will remove the issue. I want to run the car cooler though that is why I bought the cooler T stat.

Does anyone have any ideas other than "put the stock T stat back in"

My car doesn't have a cooling problem, I just want to run lower a lower temp engine so that I can run more timing and boost.

 

So, you replaced data fields in 93F and 122F with 128 and you have not noticed any AFR changes? I would block tune the whole table to 128 and see if you notice anything, then adjust your coldstart back.

Running the motor at about 150F would change multiple characteristics anyways.

You may have to adjust the IAT compensation also and/or rescale your MAF completely. When you have a 66C thermostat, the motor will not go beyond 66C, correct? If the motor is heating back up to 180-200 or whatever stock levels are, the t-stat is useless as it is fully open all the time, right?

Where does the 66C t-stat put you at it's full operating temp/idle/cruise/pre and post WOT in the logs?

 

I think Im gonna just put the stock Tstat back in LOL