Mazda 6 Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
3,414 Posts
Discussion Starter #1
Someone was asking about why the DBW throttle tables max out at 80% in a thread somewhere and I gave a half-assed answer, and no I can't find the damn thread for the life of me. I wanted to touch upon it anyways real quick. A while back people thought it was a big problem in terms of a restriction, but it really isn't. The throttle blade is mechanically fully open at the ~75-80% throttle position.

Some people have increased the value to 90 and even 100% in the DBW tables, and saw practically no difference in airflow. Here's what the helpfile says about the tables, just fyi.


Table Description – These tables define the throttle duty cycles indicated under three separate conditions as a function of calculated engine load, and thus requested torque. The table is referenced by the Engine RPM on the x-axis and by the calculated engine load on the y-axis. Table values are the relative throttle duty cycle the torque targeting system system will drive the electronic throttle body in an attempt to target the associated torque. Higher values mean more duty cycle, lower values mean less duty cycle.

Tuning Tips – The factory ECU settings use these table values to control the torque produced by the MZR engine. These tables most directly effect how the throttle system works during part throttle and WOT conditions. The requested torque values on the y-axis indicate how much or little duty cycle to drive the electronic throttle body with. A value of 80% throttle duty cycle represents the maximum amount the electronic throttle body can be driven. The OTS map settings are very effective and we suggest you start there.
Here's a screen shot of the DBW table A attached in case you're not familiar and can actually see it, lol.

Someone else please chime in to elaborate, clarify, etc..
 

Attachments

·
Registered
Joined
·
3,414 Posts
Discussion Starter #3
That was me
Ahh, thanks. I couldn't remember what the hell thread that was in or what section... I wasn't even sure if it was this forum! lol Hope that helps anyways.
 

·
Registered
Joined
·
2,746 Posts
Yeah I set mine from 80% to 100% and saw ~2% increase in TP(77% on AP, 87% on DH). I dropped it back to 90% with no change in the TP, so 80-90% DBW DC = max open TP.
 

·
Registered
Joined
·
3,414 Posts
Discussion Starter #6
So this is why it feels like the car produces more power at a certain part of the throttle than WOT. Very interesting.
Well that and your Accel Pedal Position (APP) Translation tables.
Table Description – These tables represent how the Accelerator Pedal Position (APP) values are reported to the ECU on a per gear basis. The x-axis values in these tables are APP read-only values and the cell
data is the reported APP values that are used by the ECU for throttle controls. These tables use read-only APP values to look up a APP value that is reported to the ECU for throttle controls.

Tuning Tips – The stock values work very well. If you are to modify these values, we highly suggest you drive the vehicle and datalog APP and TPS values to get a better idea about how this vehicle drives with
the various changes.

Precautions and Warnings – These vehicles tend to use switching and blending functions for closed-loop to open-loop transitions. Please be aware of this as you start to modify any closed-loop functionality.
There's a big thread on msf about "fixing the jerky throttle" or something like that. It smooths out the APP so it's more linear. I think it's mostly for the fwd folks over there so they have more control over wheelspin, which is obviously not an issue for us. I tried early on, and hated it but that's just me.
 

·
Registered
Joined
·
1,113 Posts
There's a big thread on msf about "fixing the jerky throttle" or something like that. It smooths out the APP so it's more linear. I think it's mostly for the fwd folks over there so they have more control over wheelspin, which is obviously not an issue for us. I tried early on, and hated it but that's just me.
i tried it out too, thinking it'd make the car nice and smooth. it was awful.
 

·
Registered
Joined
·
123 Posts
So how does this affect any TPS driven tables (like Boost Targets)?
At 100% APP I'm only getting like 66 Throttle DC, and ~76 TPS. Or is TPS some how re-scaled so that ~80% = 100 in the ATR tables?
 

·
Registered
Joined
·
123 Posts
So the axis on Boost Targets that is labled TPS is not really TPS. Just tried live tracking on both the boost targets, and Req. Load tables and the cursor never leaves the 0.00 row. So is the TPS on that table a scaled version of the TPS we see? (0-80 TPS input -> 0-100 Table TPS)
 

·
Premium Member
Joined
·
2,168 Posts
I don't think live tracing works yet. Trey from COBB said he got it working on most tables and it will probably be in the next ATR build soon (but maybe not so soon) to be released.
 

·
Registered
Joined
·
2,746 Posts
So the axis on Boost Targets that is labled TPS is not really TPS. Just tried live tracking on both the boost targets, and Req. Load tables and the cursor never leaves the 0.00 row. So is the TPS on that table a scaled version of the TPS we see? (0-80 TPS input -> 0-100 Table TPS)

I'm pretty sure the APP Translation tables result in the TPS value. The throttle plate doesn't have a table value AFAIK. So, the TPS Read-Only value is the APP translated value.
 
  • Like
Reactions: wdautrem

·
Registered
Joined
·
123 Posts
Oh.... so the TPS-Read Only is not really from the TPS, it's derived from the APP transition tables? Wouldn't have guessed that. :D
 

·
Registered
Joined
·
123 Posts
Oh, wait. That doesn't work either because the APP translation tables are basically 1:1. So you would still not hit the 100 TPS row on the Boost Target table. :confused:
 
1 - 14 of 14 Posts
Top