Q offset rpm (filtered)

[sssbassil]

and whats this about?

can someone please tell me what this table dose thanks,

[Matt]

Its one of the tables Calum on the SR20 forums defined in the XDFs which has made it into Nistune but I dont have a clear understanding yet of its affects. I'll put it on my list to investigate further

[sssbassil]

sweet

[Matt]

I've been asked about the SR20 enrichment tables again this week. Also previously been going through the SR20 code and tables which Calum put together in his XDF files for TunerPro

Unfortunately apart from the naming and indexes, there was not much further information to provide clarification about what all those throttle enrichment tables do so far

This is what I have at the moment and requires some bench testing to clarify

8FB0 - Throttle Enrichment - Fast Movement (vs Temp index)
8FC0 - Throttle enrich fast move vs RPM (index)
8230 - TPS Determination to use fuel maps (vs TPS trigger voltage index)
8390 - Q Offset vs RPM (index)
80A0 - 'Throttle open offset vs TPS voltage (index)


So far from what I can work out:
1. 'TPS determination' indicates the required TPS voltage (at given RPM) required to switch from using TPS enrichment values to using only fuel maps

2. Values at 'Q Offset' use the current RPM as index and multiplied against the TPS voltage from table at (1) and stored. This table appears to be an additional offset (based on RPM) from switching from TP to fuel maps

3. Values from 'Throttle enrich (vs temp)' and 'Throttle enrich (vs RPM)' are multiplied together and saved for later use (see 5)

4. 'Throttle open offset' is apparently indexed by TPS voltage reference and the value is multiplied against TPS voltage. Effectively it’s a copy of the TPS voltage with an extra offset added based on RPM.

5. The offset TPS voltage is then compared against the multiplied tables from (3) and used to determine if to use the current TPS offset value, or the multiplied TPS offset values calculated from the tables at (3)

These tables determine whether to use fuel map or TPS enrichment values based on
(a) TPS position (and movement based on previous TPS events potentially)
(b) Current RPM
(c) Current coolant temperature

The main one to modify would be modify the values in 'Throttle enrich (vs RPM)' which is not currently in Nistune. It would be a new table to be added. Once I confirm the indexes are traced correctly with hardware tracing, I will then need to exercise the TPS movements against the tables to determine they are doing what we think.

[Adrian]

Are there any News or bench Test related to the accerelation tables on Sr20's?

[Matt]

TPS usage depending on these tables is quite quick as it uses the position in response to acceleration before the MAF sensor voltage is read

We found that this one:
TPS Determination to use fuel maps (vs TPS trigger voltage index)

Has the main effect when switching from using the TPS to the fuel map settings and had the most effect on the bench. We are going to try this out on the vehicle next during the next dyno session