Desired Load; ETC Torque Request - Where does pcm pull this?

[Justinjor]

Working on shop twin turbo car.
Car made 1021whp on 15psi and drives pretty decent, all things considered, but I'd like to make it better.

I suspect desired load and ETC torque request being drastically incorrect is a problem and I'm not sure how to fix it.

Calculated load goes up to 1.9-2.1 which makes sense at 15psi but desired load never goes above 1.1 and ETC torque request is always around 475-480ft lbs when the motor is making north of 850ft lbs.

Surely this is a problem but I'm not sure how to fix it.

Can anyone point me in the right direction?

etc_torque.png

[murfie]

Make sure your SD can calculate MAP as high as it is actually getting to. Then raise load at WOT, aircharge multi, and maximum load.

Desired load, comes from desired torque. the TB model and driver demand tables work together. the TB model is limited by the stock SD.


A clean smooth MAF signal is usually the only thing stopping most people from tuning great drivability. The ECU will try to follow a shitty signal with the throttle blade. Some times the SD can be massaged to help smooth it out, the spark tables get effected by load and those can be massage to smooth it out as well. But its a ton of work compared to just fixing the source and not band aiding the calibration because of a poison MAF signal.

[Justinjor]

Make sure your SD can calculate MAP as high as it is actually getting to. Then raise load at WOT, aircharge multi, and maximum load.

Desired load, comes from desired torque. the TB model and driver demand tables work together. the TB model is limited by the stock SD.


A clean smooth MAF signal is usually the only thing stopping most people from tuning great drivability. The ECU will try to follow a shitty signal with the throttle blade. Some times the SD can be massaged to help smooth it out, the spark tables get effected by load and those can be massage to smooth it out as well. But its a ton of work compared to just fixing the source and not band aiding the calibration because of a poison MAF signal.

I'm going to send you a PM

[Slowleen]

im having this same issue twin car makes pulls not much trq error very abrupt. but iv scaled the torwue tables and still getting stock trq request and indication

[Thatwhite5.0]

Both torque and inverse tables need to be rescaled and the cells need increased or repopulated. The 3d model helps greatly to keep the same gradual increase.
If you use the the inverse table, rescale the bottom two rows torque values (the highest torque) on the axis and rescale the load values in the cells.
The indicated torque tables torque values need calculated as well as the bottom two load values on the axis.

This is just a starting point.
Stock indicated axis ends with .9 and 1.2 load. Copy the 1.2 load row into the .9 row. Rescale the load correctly by change .9 to 1.2. Depending on how much psi, change the last value to 1.6 load. Use the 3d model and multiply the stock values on the bottom row by 1.01% until the 3d model looks correct. Count how many clicks so the next table you can multiply by 1.4 instead of clicking 40 times.

The inverse axis bottom two cells. Copy the highest torque value to cell above it and copy the bottom row to the row above it in the table.
Change the highest axis torque value to 663, 700 or 737 depending on what load your indicated table or psi will be. Recalculate the inverse cells with the torque tables cells.
That's just a starting point.

The tt/inverse will take some time for sure, and this is why I 100% recommend disabling Mapped points. If you can cut down from 26 tables to 14 tables. That's half work and time spent calculating. You can cut down to even less than 14 tables.

OP you're calculating 2.0 load. I'd use 1.25, 1.5 and 2.0 for the indicated axis.
The inverse axis I'd use 516, 663, and 847.5 or 884 ft lbs.

Increase driver demand to increase ETC torque request. I haven't had an issue with the request being less. The TB for sure effects the request but increasing DD increases request. On s550s, there's a limit to the amount you can request, I believe it's 737 ft lbs.

[Slowleen]

so I rescaled my tune and this is what it looks like, going to do a test pull and see if the car likes the changes. im also noticing my maf surges up and down while climbing? causes?
also vct will switch between OP and best fuel economy?
New tune rescaled
TT tune rescaling OP trq table.hpt

Old tune
TT tune trq idle air.hpt

[Thatwhite5.0]

That will not work for you. If you rescale one table, all of your torque tables need rescaled. 0 - 3 just needs some minor changes and need to be recalulated. I just noticed your IVO angles. Do the car run in OP? It looks like it would blend between all of your mapped points. The MAF surging is cause of your IVO angles and how they're running working with the torque tables. I would return the IVO back to the stock 0*, it will probably run a lot more smoooth and be stable. I would return all angles in 38150 and 38151 and run MP 0-3, 7 and OP. Ofcourse OP would be for hauling ass, the other 4 MPs would be to cruise around with out any drivability issues. Is this a street car? Or is it a race car that just needs to drive from the pits to the track? You are able to drive the car. You know where and when boost will build, and at what load. If you're able to use the stock torque and inverse tables up to 70% load, use them! That also means you'd have to use the stock cam angles for those enabled mapped points. The stock cam angles would be nice if it's a street car, then those angles wouldn't matter WOT as it will run everything in OP.

Your OP torque table has the highest torque, as it should. The rest of the torque tables need to be rescaled, but the inverse axis is scaled nicely for them. You really want to be more in control of your torque/inverse tables at WOT. Having the cells populated in the load your at.
See how this table is scaled and the air load values it that are in the cells. Then comparing it to 811 ft lbs more near where your OP Indicated table is scaled to which puts the inverse table's load value more near to where you're at.
11inverscale1.PNG 11inversescale2.PNG



The switch between fuel economy and OP is your thresholds. Increase them to keep them out of OP.
11openable.PNG

[Thatwhite5.0]

Don't forget about driver demand. If ETC Torque Request is limiting you.
11driverdemand.PNG

Can you post a datalog?

[Justinjor]

You're better off starting a new thread so this one doesn't get jumbled up.

[Slowleen]

You're better off starting a new thread so this one doesn't get jumbled up.

Sorry about that.
So it seems the way I scaled it was pretty close. And if I?m correct reason you are getting etc torque request limit is because your driver demand isnt scaled for your calculated trq

[Thatwhite5.0]

Damn, it already got messy. My first answer was to OP. Then I thought OP posted his tune and log. I then thought, this doesn't look like 1000HP.

Justinjor, , your torque/inverse appear completely stock from the datalog pic. The picture I posted of the four tables in post 7 will give you an idea of how the the tables calculate and and how yours should appear but with more torque and air load.
Murphie always says how these tables effect fueling and mentioned your maf signal. This picture was from a boosted 3v I adjusted just to show the difference in the calculations and roles these tables effect. Definitely do not need lean conditions WOT at 6000 RPM.

EFFECTSoftorqueinverse.jpg

Load increased, MAF lbs increased but MAF volts decreased meaning LEAN. If MAF volts did not decrease, it would still have been lean.. I'd have to add more fuel in the correct cells. If I added fuel where needed and the MAF curve starts getting jagged instead of keeping a smooth curve, I'd have to sort that out with the torque/inverse tables and recalculate. The axis of both tables are very important. They're what each cell on the row calculates with and the axis have a relationship with the cells in the other table.