BA throttle dip

[will15]

Hey guys I’m tuning a BA turbo and when doing a pull on the dyno at the start around 3000rpm it will go to WOT then dip a little then back to WOT any ideas on what would cause this?

[Puffwagon]

I used to see my car do that in 3rd gear only (zf6), it was a form of trans truncation.

[will15]

30 minutes ago, Puffwagon said:

I used to see my car do that in 3rd gear only (zf6), it was a form of trans truncation.

Just set all this stuff to 0 and still doing it.

[Puffwagon]

I changed the maximum input shaft torque to 1200, dunno if that's what fixed it

[will15]

34 minutes ago, Puffwagon said:

I changed the maximum input shaft torque to 1200, dunno if that's what fixed it

Just tried that no dice.

[Puffwagon]

This is in my tune

auF2184 Maximum allowable input torque is 1200

auF1741 Maximum Input Shaft Torque before stall torque truncation is used (In forward gears) is 750

auF1795 Maximum Input Shaft Torque before torque truncation is used  is 1200

 

[will15]

Just a thought am I looking at the right Scaler  for this (TP raw) or this scaler giving me a bum steer and it’s something else making it surge.

[Puffwagon]

What happens if you start the run at 2000rpm? Mine would start with the throttle partially closed and only go to WOT after 3500 or so. Could be a completely different issue, especially since you're looking at a BTR.

[BeerTurbo]

8 hours ago, will15 said:

Just set all this stuff to 0 and still doing it.

i dont think that's the right way to disable it. that's just telling it to use mode 0, which might actually still include TQ reduction.

 

AUF0264 AND AUF0265 have been where i have had the most success disabling throttle movement on TQ retard.

you can see the transmission is requesting tq retard. so you can disable the throttle part using those two scalars.

 

it may still then default to pull spark and or another event such as cylinder cut depending how your other tq events are setup.

you need to do as puffy suggesting and find out where in the calibration the limit is and change it.

 

for fun check auf3342. ,max throttle angle

 

 

[Roland@pcmtec]

What does torque source say? That will tell you which truncation is kicking in. 

Might be oscillation/ tip in etc

[will15]

1 hour ago, Roland@pcmtec said:

What does torque source say? That will tell you which truncation is kicking in. 

Might be oscillation/ tip in etc

How do I log torque source I can’t find it in the log channels

[will15]

Ok so it looks to be transmission torque issue, torque source drive by wire channel is saying (transmission truncation) so how do I turn that off or resolve this issue?

[dat111]

I believe it's under torque requesters. 

DO NOT turn it off. Or it's a good way for the gearbox to poop its self

[Plumbs]

On 11/26/2022 at 3:05 AM, dat111 said:

I believe it's under torque requesters. 

DO NOT turn it off. Or it's a good way for the gearbox to poop its self

Agreed ! 

[BeerTurbo]

On 11/25/2022 at 3:55 AM, Roland@pcmtec said:

What does torque source say? That will tell you which truncation is kicking in. 

Might be oscillation/ tip in etc

why does Tip in kick in?

on the data log i was looking at, when it goes into boost around 3k tip in kicks in, but if you ease into boost later in the RPM it does not.

[Puffwagon]

Tip in is there to make things smoother upon throttle application, it is mainly for carpark use. If you go straight from low power tune settings to high power tune settings there will be a noticeable shunt in the car and your body.

[JoshW]

On 11/25/2022 at 6:55 AM, Roland@pcmtec said:

What does torque source say? That will tell you which truncation is kicking in. 

Might be oscillation/ tip in etc

Hi Roland

So if my car is cutting spark and misfiring at say 3k and the torque source says that its tip in Oscillation, stock value is set to 3 should I increase or decrease this value? or should I be looking at something else that is causing it like spark or fuel, I can see that the cat is getting over 800 degrees so from that I guess it's running too rich?