WOT not opening full throttle until 4900rpm why

[Benjamin Lopez]

Hi team, can anybody say why in my Pentastar the WOT does not open the throttle to full (86.3%) but instead it ramps immediately with the pedal command to 76.9% and then it stays there until 3,000 rpm when it starts ramping up slowly until reaching WOT 86.3% at 4,900 rpm?

I tried increasing the feedforward max demand voltage at all rpms to 3.7Volts, but this made no change4 so I understand its the NN holding down here?

Can you give me any light?

[SultanHassanMasTuning]

post file, there is adjustments

[Benjamin Lopez]

attached .hpt and the trending. Thanks a lot in advance.

[SultanHassanMasTuning]

Airflow
forward Control

2.13553113553114
2.46398046398046
3.66544566544567
3.7997557997558
3.7997557997558

[Benjamin Lopez]

Thanks a lot Sultan: I did that already... see the attached previous file and trend (this is previous file version), but I first added like you propose 3.79Volts already from 2000rpm and as it did not work then I went even beyond that and I added 3.79V in all the table from Iddle ... and nothing: still the throttle max opening gets hold until 4,900rpm

There needs to be something else, or the NN is not letting it open. I saw another guy with Pentastar similar year asking same question but he got no response. I appreciate your help.

[HaasExp]

You need access to [ECM] 35059 - WOT Override Throttle Setpoint table. Looks like its not currently defined for your vehicle.

[Benjamin Lopez]

Aha... I was looking at the navigator and I don?t find that one, does it have any solution? or I need to live with this throttle miss at WOT? ideas?

will it help disabling the throttle adaption?: I did read to some posts that may turn to an unstable idle)

[SultanHassanMasTuning]

yes there is usually 2 tables for throttle

check with BETA is its there

[Benjamin Lopez]

Thanks Sir, checked Beta and no luck. Any thing else can try from imagination? or am I as licked as my TB?

[SultanHassanMasTuning]

you have to email support if they can add this table

[Benjamin Lopez]

thanks a lot both: I did open ticket on the software support. Will feed back.

If its not for you guys I could continue crashing my head against a wall for months. I would never have discovered this myself.

[duster360]

Throttle only needs to be open enough to bring plenum pressure to Barometric. Any more than that does nothing

Your manifold pressure is already flatlined throughout the entire "WOT" pull. So opening the blade any more than what it is/was, wont do anything.

[Benjamin Lopez]

thanks Duster, I see what you are saying, and I think (I just think... I am willing to hear your view because probably I am wrong) that the fact that the manifold pressure stabilizes pretty much at 92-94KPa along all the rpms range of suction, does not necessarily mean if I open TB more or install bigger one it may get even closer to 95.14KPa barometric pressure 13.8psi I read?

whats the closest you guys with experience have seen to get the MAP to the atmospheric pressure on atmospheric engine?

[duster360]

thanks Duster, I see what you are saying, and I think (I just think... I am willing to hear your view because probably I am wrong) that the fact that the manifold pressure stabilizes pretty much at 92-94KPa along all the rpms range of suction, does not necessarily mean if I open TB more or install bigger one it may get even closer to 95.14KPa barometric pressure 13.8psi I read?

whats the closest you guys with experience have seen to get the MAP to the atmospheric pressure on atmospheric engine?

+/-2Kpa is more sampling error than anything worth chasing.

The PCM only opens the TB as far as it needs to so that the engine is more responsive to throttle changes.
If, for example, the TB only needed to be open 70% to max out plenum pressure to barometric but you forced it to be 100%, then if the ETC needed to reduce engine torque (off Pedal, Shifting, TM, ect) the blade movement from 100% to 70% wouldn't translate into any torque reduction and be laggy.

[Benjamin Lopez]

Thanks Duster: I asked HP Tuners support and they added the function to me to override the throttle opening voltage. This enabled me to go max opening and I tried a log like that: you are totally right: no improvement, I understand the logic of what you say that if it opens more than effective then reducing the torque command will have a lag. Fully understand and confirm here.

Guys, I will open another post for Pentastar cam overlap at PT for Exhaust Gas Recirculation. I made an excel file and I see 57 crank degrees overlap at 1900 rpm... how possible? is this the cause of the very small engine feeling at 1500-2000 rpm I feel?... I open another post because I made a considerable info tracking that I want to share, appreciated if you participate on the discussion too.

[2016300SAWD]

I can hit full WOT at 1,800-2,400 RPM starting from a dead stop. Try these changes not as aggressive as mine, but will make a difference compared to the 3.6 tune you posted.

Fuel-> Power Enrichment-> WOT Pedal Thresh= 2.75V & WOT Delay= 1.500 s

Torque Management -> Driver Demand-> Pedal WOT 2.75V

[HaasExp]

I can hit full WOT at 1,800-2,400 RPM starting from a dead stop. Try these changes not as aggressive as mine, but will make a difference compared to the 3.6 tune you posted.

Fuel-> Power Enrichment-> WOT Pedal Thresh= 2.75V & WOT Delay= 1.500 s

Torque Management -> Driver Demand-> Pedal WOT 2.75V

Correct me if I'm wrong, but I believe your WOT flag will be set when your relative pedal voltage >2.75V but your relative TB voltage will still be well below 3.8V (TB WOT) at 1,800-2,400 RPM without setting [ECM] 35059 and [ECM] 44389 all to 3.8V.
These parameters are used to "clip" the TB to the effective WOT position.