roush os, what is this limit?

[mJolnir]

I was working on a roush charged 2017 gt today and around 6900 it seems to hit some limiter and ignition timing drops 9 degrees, but i cant seem to find what limit it is?

here is the log
dyno6.hpl

here is the hpt
tune1100oct.hpt

this is the "stock" roush tune
tune0roush.hpt

[Thatwhite5.0]

Id start by increasing your driver demand in column "90". Multiply by 1.08.

ddincrease.JPG

Add ETC Area and Throttle Angle Error to your channel list in the scanner. Normally when you go WOT, your throttle body opens to 82 degrees and your ETC Area begins at a low number like 4, and it gradually increases to 40 or 50^2 until you let off the pedal. What's happening is, your throttle body opens to 82 degrees, and your ETC Area begins at 4 and gradually increases, but in the middle of your pull, ETC area decreases, closing your throttle body. Your driver demand is your limiter.

[mJolnir]

Id start by increasing your driver demand in column "90". Multiply by 1.08.

ddincrease.JPG

Add ETC Area and Throttle Angle Error to your channel list in the scanner. Normally when you go WOT, your throttle body opens to 82 degrees and your ETC Area begins at a low number like 4, and it gradually increases to 40 or 50^2 until you let off the pedal. What's happening is, your throttle body opens to 82 degrees, and your ETC Area begins at 4 and gradually increases, but in the middle of your pull, ETC area decreases, closing your throttle body. Your driver demand is your limiter.

im not seeing the throttle close more than 0.08* and is for a very short moment, where are you seeing it close?

[G-Town-GT]

Driver Demand table is ignored as soon as Throttle Control Pedal state enters WOT. Im running a stock DD with 800RW, drives like stock and pulls like a Train up to the limiter. Your engine goes in TQ based deceleration shortly before 7k rpm. Changing your DFCO back to stock might be a good idea, as this is the only strange thing I see in your cal.

[G-Town-GT]

What Hardware setup are you running ?

[Thatwhite5.0]

I'm not sure about it ignoring driver demand completely. Torque source says driver demand and the torque ratio tables still play a role even at WOT.

If his driver demand was higher, his car would probably run different, run better and show more engine brake torque.


edit, not saying raising driver demand will fix the problem, just a starting point. I came across this before, just trying to find the log and file.

[mJolnir]

What Hardware setup are you running ?

its a 2017 auto gt with a roush sc kit, we eliminated the cats and it has the noisiest borla catback, its all on 100 octane fuel and the dyno graph you can see the step down on power, i would upload it but for some reason its not letting me

[G-Town-GT]

I'm not sure about it ignoring driver demand completely. Torque source says driver demand and the torque ratio tables still play a role even at WOT.

If his driver demand was higher, his car would probably run different, run better and show more engine brake torque.


edit, not saying raising driver demand will fix the problem, just a starting point. I came across this before, just trying to find the log and file.

Interesting finding, However according to ECM 44373 / 44374 DD is first partly ignored, but as soon as Pedal is at WOT end it is completly ignored. I will give it a test on the dyno in future. Torque source driver demand to my knowlege is perfectly fine, just means that the driver is interacting with the Pedal, and the PCM is in return working with this signal, as long as no other limitation sources are signaling a different status. Example Torque sources like: Trans Shift modulation, TQ+ from Trans, Idle Speed limit etc etc. Would be cool to see more about your findings in this direction.

[G-Town-GT]

its a 2017 auto gt with a roush sc kit, we eliminated the cats and it has the noisiest borla catback, its all on 100 octane fuel and the dyno graph you can see the step down on power, i would upload it but for some reason its not letting me

What Pulley size are you running?
And what type of Intake ?

[mJolnir]

What Pulley size are you running?
And what type of Intake ?

85mm pulley and stage 1 intake

[18f1505.0roush]

Seeing the same thing on my 18 f150 with a Roush. I raised the rev limiter and that was like a dadadada when hit but now at about 6900 hitting a limiter feels like a pause or something different than normal. Curious what you found

[18f1505.0roush]

Found limiters in the trans seemed to fix it

[veeefour]

Driver Demand table is ignored as soon as Throttle Control Pedal state enters WOT

I tend to disagree. I find that DD is still used @WOT as you still need to project your torque for calculations like IPC.
Requested torque @WOT doesn't come from nowhere - it's coming form DD.

This is one of the biggest misconceptions about Ford Torque Model.