Link G4+ Fury E-throttle delay

[Kirpich]

Good day. My name is Artem and I'm part of the team currently building 2JZ-GTE powered drift car in Russia.

One of the problems we encountered after setting up and rolling road tuning the engine management is noticeable throttle delay from 0 point.

Bacically when the driver pushes the pedal, initial response is somewhat delayed. The car is being used for drifting, and it causes problems.

Most likely there is something we are getting wrong with setting up the e-throttle system.

The hardware we are using is:

Bosch Motorsport 68mm e-throttle body

Penny&Giles hall type accelerator position sensor on a Tilton pedal assembly with dedicated linkage.

What do you recommend to do and at which parameters to look at to reduce this delay?

[wastegate]

Heads up, will need at least a log. That way can see the difference between the Throttle Position (TP) and Accelerator Pedal Position. (AP).

Also the map is handy too to see the settings. 

[cj]

Heres one I wrote a few months ago for someone else asking a similar thing. Make yourself familiar with the "ethrottle target" & "TPS main"  values in the logs, and then look at the below PID tuning to get TPS to track the target more closely. Well tuned ethrottle responds about as quick as cable so you can definitely get there with some tweaks.

 

[Kirpich]

Thanks for advice, will definetly look into this.

In the meantime, here is the project file. I'm not able to upload a log file here, as it exceeds the upload limit.

Vesta_Krasnoyarsk.pclr

[Kirpich]

Running through my log file I think I found at least one problem. 

When I checked my E-throttle target table I saw that AP (Main)% doesn't change at all, but RPM changes.

Which means, at least to my understanding, that my throttle is running off only AP (Sub) signal.

The sensor itself seem to be ok, what can be the problem?

And here is a shortcut for the log file

https://drive.google.com/file/d/1Iu4evtDkq9l2EGVboslGDvUR0nEd76qQ/view

 

[Simon]

In the Log you have not logged APS Main so there is no data for it the E throttle target is also not logged. 

[Kirpich]

Good day.

I see, will make a new log then.

Simon, in the meantime, can you please take a look into project file I uploaded. Do you see any mistakes in E-throttle setup, or sensor calibration?

Maybe there are some suggestions about PID for the throttle body we are using (Bosch 0 280 750 156)

[immy21]

For a starting point try p=7, I=0.1 & D=45

That's what I'm successfully using on my 60mm 0 280 750 151 for the last 500 miles
I planned on updated my thread once I put a bit more miles on it, have a look:

 

http://forums.linkecu.com/topic/10242-bosch-motorsports-60mm-pid-settings/?tab=comments#comment-67807

 

[Kirpich]

Thanks for PID immy21

Finally, I recorded normal log with AP main; TP main and E-throttle target.

Also, made a few tweaks based on cj's recomendations

Vesta_e-throttle_PC_2_with_target.llg Vesta_e-throttle_work_last.pclr

[Kirpich]

Good day.

Have been playing around wit PID and E-throttle table target and there is a huge improvement in terms of throttle pedal response.

But now encountered another problem: After startup, engine RPM surges several times, and only after that returns to stable Idle at target RPM.

 Does anyone have suggestions about what is causing it? Have tried to change Base Idle table< no noticeable improvement.

I am attaching the project file and a short log

Vesta_e-throttle_intermediate_3_30_08.pclr Vesta_e-throttle_PC_30_08_last.llg

[cj]

Can you post a log of you starting it up so we can see the surging behaviour? The last log shows it already running 

[Kirpich]

Good day to all.

Finally, I have been able to record a startup log. I have tweaked Idle tables as well as Ethrottle target at zero AP (Main) and RPM surge on startup got a little better.

But still, at first RPM rise and then slowly get lower to the target RPM set. In the attachment is the log as well as latest project iteration

Vesta_e-throttle_PC_05_09_STARTUP2.llg Vesta_e-throttle_intermediate_7_05_09.pclr Vesta_e-throttle_PC_05_09_STARTUP.llg

[Kirpich]

Also have an unrelated question: I have started tu set up Anti-lag and to arm It I wanted to use a button on my CAN keyboard (running a PMU and keyboard connected to my Link Fury via canbus), but, as I understood I cannot use CAN Digital input to arm and disarm Anti lag. I have to use an actual switch connected to one of available digital inputs. Am I right?

[Adamw]

Use a virtual aux.

[cj]

Your high idle is caused by 2x things

The first 4-5 seconds is because for the first 4.5 seconds after initial startup, the ecu adds the "startup step table" value to the TPS target. So instead of 7% TPS you run ~10% for 4.5 seconds then it goes back to normal ethrottle target at about 1400rpm. You probably want a bit of this behaviour but can tweak it down a little bit so its only adding 0.5 or 1% maybe. Fix this second once you have the base idle values correct.

The second problem is that your base idle table is quite high, so in open loop idle you would be running 7-8% TPS which is why you get 1400-1500 rpm idle for the first 30 seconds or so. After that, closed loop idle control pulls enough% out of the target to lower your RPM to ~1200. At this point you are more in the 4.5-5% TPS range. Remember TPS target is ethrottle table value + base idle value + any other values. "3% base idle step" does not mean 3% of your target number (ie 3% of 5%), it means 3+5 = 8%. To fix this, i would take 2% off either all cells in your base idle table, or 2% off all values in the 0 row of your ethrottle target table. Either change will means your open loop idle is ~5% where it needs to be, and so closed loop will have very little to modify. This will also mean your inital startup TPS% is 2% lower, which may be enough to fix that issue as well, hence why you fix this first.

[Kirpich]

Good day to all.

Thanks for all advice, it's been very helpful. I fixed the RPM surge on startup and now both E-throttle and Idle Control are working nicely.

Also I have setup the Anti-Lag, just to try it out. It is definitely working, even with rough tables. But not sure I made everythin even roughly correct, so, now I need to tune it and I am not sure which way to go. Can anyone take a look at the setup and suggest what's wrong and what's not?

Vesta_e-throttle_PC_06_09_anti lag RAW3.llg Vesta_e-throttle_final_anti lag RAW_06_09.pclr

[Adamw]

Antilag is meant to work only when you liftoff from high RPM, it doesnt appear to be how you are testing it in the log.  You will need to test it more like how it is intended to be used.  Your basic setup looks ok and it appears to work in a couple of areas in your log where the RPM gets high enough.

Be aware that your brakes will not work without vacuum so it is very dangerous to use it on a road car unless you have a pedalbox fitted or some other modification to the brake system such as electric vacuum pump.  

[Kirpich]

The car uses Tilton pedal box with twin cylinders and is itself built for drift competition, so, no worries about vacuum.)))