Tune #2014_10_16_0003
Not logged.
B3306 - Cold Engine RPM Limiter (RPM) - 176 thru 284 coolant temperature changed from 5000 to 7000 rpm
B4315 - Throttle Follower Airflow - 0.51 thru 3.55 TPS% increased 20% and manually smoothed.
B4316 - Throttle Follower Airflow RPM Multiplier - increased from .17 to .18
Mostly played around with the throttle follower tables with the hopes of increasing throttle response. But the more I thought about it, the less I had hopes that this would do what I was hoping for. But I loaded the tune anyway, just to see what happens.
Actually it WAS an improvement, but not in the way I had expected.
From what I can gather, the throttle follower tables are the digital equivalent of the dashpot on a carburetor. For those of you who don't know what this does, it softens the release of the gas pedal to keep the plate from slamming shut abruptly and causing a sudden drop in engine rpm and subsequent power. Which would cause a possibly unexpected engine braking effect. So the dashpot acts as sort of a shock absorber in the way it works on engine rpm in relation to the gas pedal.
Anyway, what the changes I did to the tune seemed to slow down the engine rpm drop when I would take my foot off of the gas pedal. This seems to have made overall driving just a lot smoother. Since the engine doesn't drop RPM so quickly between shifts, shifting just seems overall smoother and not as jerky from the time I let of the gas pedal prior to engaging the clutch and then pressing the gas pedal again after releasing the clutch after the gear change. Coming to a dead stop seems smoother too as the engine RPM drops gradually and smoothly. I was also able to cruise on my dirt road at only 8 mph without any noticeable surging, so I guess the surging was caused by the PCM trying to use the throttle body plate (air flow) to hunt and peck for the desired RPM, and the swings were smoothed out when I slowed down the follower values.
And I think actually acceleration was improved a slight bit, since during shifting the RPMs didn't drop so much between shifts, so the subsequent pressure on the gas pedal wound up starting from a higher rpm level than before.
Perhaps looking at the throttle cracker tables might be worthwhile at this point.
So I've got the tune progressively better than before, in an unexpected manner, but apparently have to find a different tree to bark up for what I am really after. What I think I need to find is the digital equivalent of the accelerator pump. Seems to me I tried finding that before, with no success, but maybe I just need to keep on digging. I didn't think the throttle cracker tables would do that, but perhaps I'm mistaken and just need to try them. Or maybe there is no single table set for that function and it is a combination of two or more seemingly unrelated tables that will act in that manner.
As can be seen, not much is glaringly obvious in this tuning stuff.
Linear Mode
