Fuelling type differences

V3 BETA TESTS
1

Hello, I have been having huge problems with the throttle response and pressing throttle when lower rpm littlebit too fast causes rpm to drop and lambda to spike lean for some time, this causes lag when tyring to accelerate. I tried to play with acceleration enrichements for a long time and aldo with injection timing and changed the map hose for better and shoter one. this made some differences but there is still notable spike coming from faster throttle movements.

Now I changed the fueling type from speed density to alpha-N with map multiplication and all those issues are gone. So what does Alpha-N this do differently and where should I try to find solutions for car to be working like this using speed density calculations?

with alpha-N I noticed that the lambda is not following lambda target table, should this have something to do with the problems i have with speed density?

in this log there can be seen large spikes when going on throttle but in the end I changed to aplha-n and map and these spikes are gone.

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2

There are two options:

  1. Now you have different VE table
  2. MAP response was very slow, for example too much filtering, too long vacum line, etc.
3

Ve table is same. I only change fueling type, nothing else. And i check its not chaning ve tables.

How long should the vacuum line should be max? I have my ecu inside the car so its around 2m long.

4

this is my map settings
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5

VE cannot be the same as the on the axis there is MAP or TPS.
It isn’t 1 to 1

You can look at the log how the MAP react to the TPS change. The vacuum lines should be as short as possible and also quite rigid (non expandable)

6

Okey, I see that now. How could i make my tps scaled ve table to match my map based.

7

It is not possible.
You need to tune it with Alpha N or retune it in Speed density.

When you press the throttle the MAP / TPS increases and the readings from VE table are taken from different cells. If the values in the cells aren’t properly set it can also cause rich / lean conditions.

8

When I am setting fuel type to alpha-n with map multiplication and map based ignition, it still reads ignition from tps % not map%

9

I will check it, as it could be a bug

10

I have now used autotune to create the ve table while using speed density.

So do you think I need to manually create it to work more like the tps based aplha-n table so I will get rid of the lean spikes I am having?

I was checking log files and the map sensor vs tps lag was only around 0,1-0,2s