Quote:
Originally Posted by Sleepless
Given how sensitive the engines seem to be regarding injector seals and lots of track driving, I'm a bit hesitant to add N/A performance parts like a de-cat header, and being confident that the custom tune is safe for lots of track use.
I haven't heard of anyone having an issue with just a header and tune, but I still worry. Should I worry? Or, is it dirt simple to get a safe tune?
Anyone out there with NA mods and a custom tune tracking the car a lot?
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Assuming your tune is already pretty good for street. AFR knock fuel trims ect.
Log your tune on street check its pretty well knock free during street driving and normal temps. Sort out any knock during street driving or single dyno pulls at normal temps first.
best simplest "insurance" for track day is a tank of really good fuel
Their are tables in the ECU to reduce timing when Intake Air temps climb and when ECT Engine coolant temps increase.
Timing compensation (IAT)
Timing compensation (IAT) Compensation
These two tables work in conjunction with each other
eg at IAT -122F retard is -2.11 degrees but it will be applied differently depending on engine load/RPM eg at engine load =1 rpm = 6000 the scaling factor is -70% do actual retard = -0.663 degrees
0% = full retard applied
-100% = no retard applied
This is for romraider, ecutek labels and scales these tables differently but they work the same.
What you can do is alter the scaling or the retard values where you see knock start when temps increase at the rpm/load points.
Suggested starting point would be altering the -70% values in the 5000-7000 rpm ranges to -50% to increase the retard at higher IAT temps higher load/rpm
I also insert -1.4 degrees at 104F just to get the compensation to cut in a bit earlier. in Timing compensation (IAT) table.
Then have a look at the
Timing Compensation A (ECT) Engine Coolant temp
Timing compensation B (ECT)
You will notice on some tunes (including stock tune) these are all zero ie no retard applied regardless on engine coolant temp
For a bit of safety add maybe -2 degrees retard at 212F and -3 degrees at 239F coolant temps ie change the last two cells. (this is what most WRX ecu run.)
