The default XLR programming includes 0.5 AFR richer tuning at 6000 RPM to cool the pistons. Ideally there would be a timer associated with it — say after 10 min at 6000 RPM it added — but there is not. For this tune I removed that variable in order to study the impact from 6000-6400. Since there were few other changes in the tune we are focused on the 6000-6400 RPM range.
Specific Changes in Tune 5D:
- raise piston protection rpm to 8192
- reduce IAT retard
- point advance reductions around 5400 rpm to eliminate slight KR
The blue line is today’s test. The red line is Tune 5B in hotter weather. From 6000 to 6500 rpm the Blue line goes up 4 whp from 224 whp to 228 whp instead of staying flat as in prior tests.
The Virtual Dyno test results always seem muted in cooler air, which is counter intuitive. I wonder if there are other factors such as the air pressure in the tires (reduced in cooler weather) which are impacting the test results.
The calculated hp in HP VCM Scanner showed a peak of 316 hp.
The calculated peak torque was 308 lb ft.
Overall I was glad to see a positive impact from 6000-6800 rpm and no knock retard. I am uncertain why cooler weather tests seem to record lower results. My intuition is there is a variable I am not controlling for.