DATALOGS
Datalogging this car has been great, affirming design decisions and money spent on parts. Here are a number of charts from one of our first datalogs we did a few weeks back.
Note we still have some dialing in to do - some things are still off in the tune. We haven't been to a dyno yet to check numbers yet either.
Here's a look at a nice pull from idle. The RPM is in blue
- starting at 1000RPM (we were stopped) at 877 seconds (on the bottom)
- then going up to 6500 rev limiter 878 seconds, wheels spinning
- driver came off the pedal to get traction at 878.5 seconds to 879 seconds
- shift from 1-2 happens at RPM drop at 882 seconds
- 2-3 shift at 885
- Long pull in 3rd from 886-892, then driver let off the gas
- Torque Converter lockup appears in 2nd at 880.25 seconds (see the dip in RPM)
This chart shows us how our fuel supply is keeping up.
The fuel rail pressure is in purple, values on the Y-axis at the left side. It looks jaggedy, but the bumps are within 0.5 PSI – very small variance
- Steady between 42 and 42.5 while idling between 875-877 seconds
- It jumps as the third fuel pump kicks in, near 877.5
- It drops again as the boost goes away around 893-894 seconds and the third pump turns off again
- The whole run we don’t go anywhere below 41.5 PSI. This is WAY different than my car with a return system where I can see it dipping below sometimes, down to 35 PSI even, or spiking a ton after a run.
Watch the coolant temp climb from 178F to 198F through this pull.
At 986 seconds we are back to 182F while cruising at 2100 RPM (1.5 minutes later!)
Look how closely the airflow (MAF Counts) matches the engine RPM’s (while the throttle blade is open)
On my Vortech Marauder, the MAF counts climb exponentially to the engine RPM - with a roots-style blower where the power is almost linear across all RPM's, the MAF counts climb in a fashion similar to the RPM.
Here is the air fuel mixture, supposed to be at 12, in actuality it was at 12.5 most of the run (more air than fuel expected)
So we know to adjust the MAF table (increase the amount of air) to bring it closer in line to what the airflow actually was - so more fuel is added to get us to the demanded 12 A/F.
Throttle position, driver had it all the way down except for when he tried to get traction back at the start (this is why the a/f jumped up to 17.5 in the above chart instead of staying at 12 the whole run)
Notice when the driver comes off the pedal at the end, the air fuel went to 20 – the coasting fuel shutoff is enabled so the engine is slowing the car down and no fuel is being used.
Voltage:
Voltage was maintained throughout the whole run, no lack of power for the fuel pumps and injectors!
Look at the voltage jump up at the end when the driver comes off the pedal! This is probably the third fuel pump turning off again.
This is the intake air temp:
It climbs from 122F to 152F in this run (heat from the air going through the intercooler), and drops back down to 122F 89 seconds later:
Back to 122F at 982 seconds in the log.
So both our engine coolant and air intake temperatures will come down back to normal after about 1.5 minutes of cruise in the car...
Hit the 10-image limit, continued in next post...
