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Been using Adaptronics for about 4 years and have been happily tuning the whole time.
I have always had what I consider a phantom boost spike when I snap the throttle open. I thought it was a failing internal 4 bar map sensor that was sticking, but recently replaced the sensor with an external MAP sensor and the boost spike is still there.
Most of the time the phantom spike is irrelevant in the performance of the car, but everyone once in a while the spike causes a rich enough spike that the car hesitates as the spark plugs struggle to fire.
I thought maybe there just is a boost spike, but my boost gauge does not show this spike. Also, the shape of the spike does not seem natural as the signal plateau's for a 1/4 second always around 8-9 psi.....
Its almost like the Adaptronics drops signal for a brief second then goes back to normal. I have posted an example below, but I have hundreds of examples....
I just can't figure this out and would like to know whats going on...
That is just the map prediction, its sort of mis leading if you are not used to how the software is using it. The map sensor is not actually reading that spike FYI.
So really all I need to do is play with predicted map table and asynchronous gain until I tune some of the richness out on tip in, then simply ignore the phantom boost spike.
Now I can stop chasing a problem that doesn't exist. That's what I want to here. Thanks
So really all I need to do is play with predicted map table and asynchronous gain until I tune some of the richness out on tip in, then simply ignore the phantom boost spike.
Now I can stop chasing a problem that doesn't exist. That's what I want to here. Thanks
You want transient fueling to be RICHER than your steady state stuff for various reasons, so maybe elaborate what you're seeing for AFRs and I can point you in the direction of what will work best.
Really though, the trick is going to be finding what the engine wants by seeing what makes it rev fastest for the least amount of fuel, then add 1-2% fuel on top of that for extra protection.
You want transient fueling to be RICHER than your steady state stuff for various reasons, so maybe elaborate what you're seeing for AFRs and I can point you in the direction of what will work best.
Really though, the trick is going to be finding what the engine wants by seeing what makes it rev fastest for the least amount of fuel, then add 1-2% fuel on top of that for extra protection.
AFR's were dipping down to 10.5-11:1 when I snapped the throttle open at 3,000 RPMs. I had the predicted MAP setting in those regions set too high and also asynchronous gain was at 200%. I took the MAP prediction down in that area and dropped asynchronous gain to 160% (to start). I'm guessing I should be shooting for 12.5-13.5:1. Once the ECU jumps to the VE table, everything is back to 13-14:1 A/F until the boost ramps up and everything settles down in the 11.5:1 area. Of course its raining outside so I may not get to test the new settings....
I always though I had a sticking MAP sensor issue, so I never tried to put much stock in tuning the predicted MAP stuff since the car was running relatively well when I stabbed the throttle.
Last edited by strokercharged95gt; 08-12-19 at 05:49 PM.
AFR's were dipping down to 10.5-11:1 when I snapped the throttle open at 3,000 RPMs. I had the predicted MAP setting in those regions set too high and also asynchronous gain was at 200%. I took the MAP prediction down in that area and dropped asynchronous gain to 160% (to start). I'm guessing I should be shooting for 12.5-13.5:1. Once the ECU jumps to the VE table, everything is back to 13-14:1 A/F until the boost ramps up and everything settles down in the 11.5:1 area. Of course its raining outside so I may not get to test the new settings....
I always though I had a sticking MAP sensor issue, so I never tried to put much stock in tuning the predicted MAP stuff since the car was running relatively well when I stabbed the throttle.
It really should vary based on how much load you're putting on the engine and at what RPM you're at.
For instance, if you stab the throttle and you're at 1500 RPM and 101.3 kPa (atmospheric), then you'd probably want closer to 12.8:1 AFR.
3000 RPM and 101.3 kPa closer to 12.5:1 AFR.
3500 RPM and 161.3 kPa, closer to 11.5:1 AFR.
etc etc.
Generally speaking you'd want leaner targets at lower RPMs and lower loads, richer at the opposite ends of that spectrum. Many "tunahs" like a steady AFR target across an entire RPM band and purely base their settings on load. I disagree.
Point is, find what makes the engine rev fastest and that's what it wants. Then add some extra fuel for cooling purposes.
Thanks a lot. I tried 160 asynchronous gain (from 200) and lowered the predicted kpa a bit in the 2000-4000 RPM area. Now I am getting a 14-14.5:1 lean spike on tip in which sometimes gives me a hesitation (too little fuel). The good news is that I was a bit rich at 200, a bit lean at 160, so 170-175 should be just right. Of course it rained yesterday, and I didn't feel like chancing death on my worn drag radials were the middle groove is non existent.
I now understand what I thought was a boost spike was just the ECU transposing the predicted MAP value on the graph (not the actual MAP value).
Thanks a lot. I tried 160 asynchronous gain (from 200) and lowered the predicted kpa a bit in the 2000-4000 RPM area. Now I am getting a 14-14.5:1 lean spike on tip in which sometimes gives me a hesitation (too little fuel). The good news is that I was a bit rich at 200, a bit lean at 160, so 170-175 should be just right. Of course it rained yesterday, and I didn't feel like chancing death on my worn drag radials were the middle groove is non existent.
I now understand what I thought was a boost spike was just the ECU transposing the predicted MAP value on the graph (not the actual MAP value).
Cartoonish-ness of programming... Very stupid to put false values overlaid where a SENSOR should be reading direct so you can trust that information.
08-11-19, 02:06 PM
