Hellcat pulling throttle

[mrnorm_hemicide]

Hey all,

Took my car to the strip for the first time, and experienced some strangeness at the 1000 ft mark. Details on the car: 2016 Charger Hellcat (A8), 2.85" upper pulley, LMI intake, 1100cc Deatschwerks injectors, 180* stat, tuned with HP Tuners, running 100 octane.

The car seemed to be strong off the line, and up to the 1000 ft mark... then all the sudden it would shut the throttle around 113-114 mph and scrub the run. I've attached a log and the tune. If anyone could take a look and let me know what could be causing this, I'd appreciate it.

- Alex

[06300CSRT8]

Looks like fueling related shut down. Clearly your injector settings are pretty far off given the -30 fuel trims during the run. Shortly after your shift, when you loose boost and power, fueling looks really wonky, your fuel trims swing massively positive yet you are still commanding WOT fueling and leaning out.

Either that your trans isn't completing the shift for whatever reason and its shutting you down.

[mrnorm_hemicide]

Looks like fueling related shut down. Clearly your injector settings are pretty far off given the -30 fuel trims during the run. Shortly after your shift, when you loose boost and power, fueling looks really wonky, your fuel trims swing massively positive yet you are still commanding WOT fueling and leaning out.

Either that your trans isn't completing the shift for whatever reason and its shutting you down.

You're right... looks like the SFTF+LTFT is pulling tons of fuel in boost... weird... the inj pw v. fuel mass data comes directly from Deatschwerks... does it still need to be adjusted depending on application? I'm used to GM's stuff where your fuel injector data is a constant, and you tune based off MAF and VE airflow... is it different with FCA's neural network?

[06300CSRT8]

Yea neural network makes it painful, given how far off the trims are, I would say best bet is tweak the injectors, there is no way your MAF curve is off 30%

[mrnorm_hemicide]

Yea neural network makes it painful, given how far off the trims are, I would say best bet is tweak the injectors, there is no way your MAF curve is off 30%

Literally the only air/fuel related variables that were changed are the inj pw v. fuel mass (and inverse) tables, inj offset table (all from DW published data), and the s/c airflow table under torque management was scaled for the 2.85" pulley.

I'll log my fuel trims vs. fuel mass and scale it accordingly, see where that gets me.

[Jay@HAP]

The car needs tuned....As mentioned it's pulling out a ridic amount of fuel. Also you need to richen up your FA WOT quite a bit. I wouldn't run one of these cars .87 Lambda.

Also what plugs are in it and what's the gap?

I would also pull quite a bit of timing out of it. Luckily you aren't getting anywhere near the timing you are calling for in your WOT Base table. That much boost, that lean, that much timing..

You are going to hurt it.

[mrnorm_hemicide]

The car needs tuned....As mentioned it's pulling out a ridic amount of fuel. Also you need to richen up your FA WOT quite a bit. I wouldn't run one of these cars .87 Lambda.

Also what plugs are in it and what's the gap?

I would also pull quite a bit of timing out of it. Luckily you aren't getting anywhere near the timing you are calling for in your WOT Base table. That much boost, that lean, that much timing..

You are going to hurt it.

Thanks for the input, Jay.

Car has stock plugs, stock gap. The WOT timing was only increased a couple degrees after running a pass with the factory spark table values... I'm sure it was pulling timing due to intake air temps... the track was packed, so I was sitting in the staging lanes for quite a long time between runs.

So aside from increasing the FA adders to richen it up a bit, I need to adjust the fuel mass v. inj PW based on my STFT+LTFTs? So the injector data provided by the injector supplier is just a baseline then? And must be adjusted depending on engine airflow?

[Jay@HAP]

https://forum.hptuners.com/showthrea...-spark-advance

To answer your question yes.

Pull 6-8 degrees out of it while you are getting your fueling straight.

To start out I would set your Commanded EQ to .78-.81 Lambda. I can't remember at the moment what FA WOT multiplier you will need to get that Commanded EQ.

Make sure both injector tables match each other, the inverse table I mean.

I cant remember what the stock gap is on these cars, you might need to tighten the gap up to .025-.028 or consider going to a colder plug and tighten the gap up.

Tuning with ANN on is pretty simple. Leave the MAF table and VE table stock.

Raise your max airflow and P ratio limits.

Don't add too much timing around peak torque.

You may have to desensitize your knock sensors some, they are pretty sensitive from the factory and the stock blower is noisy as hell, especially when you start spinning it faster.

[mrnorm_hemicide]

https://forum.hptuners.com/showthrea...-spark-advance

To answer your question yes.

Pull 6-8 degrees out of it while you are getting your fueling straight.

To start out I would set your Commanded EQ to .78-.81 Lambda. I can't remember at the moment what FA WOT multiplier you will need to get that Commanded EQ.

Make sure both injector tables match each other, the inverse table I mean.

I cant remember what the stock gap is on these cars, you might need to tighten the gap up to .025-.028 or consider going to a colder plug and tighten the gap up.

Tuning with ANN on is pretty simple. Leave the MAF table and VE table stock.

Raise your max airflow and P ratio limits.

Don't add too much timing around peak torque.

You may have to desensitize your knock sensors some, they are pretty sensitive from the factory and the stock blower is noisy as hell, especially when you start spinning it faster.

So per your write up (great one, btw), whatever I do with the PE v. air charge v. RPM table I should apply to the PE v. Pratio v. RPM table too? Looks like its set to 0.011 factory, which combined with the 0.0722 factory stoich would be right around 12.01:1 AFR or 0.87 lambda... so if I go 0.018 on the adder, that should put me at 11.08:1 AFR or 0.80 lambda.

I do have the inverse fueling tables matched, so looks like I just need to log my FTs against the fuel mass, as you recommended, and adjust.

Would you recommend pulling several degrees out of the WOT spark table just across the board?

Thanks for the help!

[Jay@HAP]

yup, your math is good.

I would put the timing table back to stock, take 4-5 degrees out from everything above 2880 RPM It's better to be safe than picking up parts off the ground.

Make sure you log throttle torque source, aircharge, injpw, fuel mass cylinder 1 and both banks knock sensor voltage.

[mxatunerjg]

https://forum.hptuners.com/showthrea...-spark-advance

To answer your question yes.

Pull 6-8 degrees out of it while you are getting your fueling straight.

To start out I would set your Commanded EQ to .78-.81 Lambda. I can't remember at the moment what FA WOT multiplier you will need to get that Commanded EQ.

Make sure both injector tables match each other, the inverse table I mean.

I cant remember what the stock gap is on these cars, you might need to tighten the gap up to .025-.028 or consider going to a colder plug and tighten the gap up.

Tuning with ANN on is pretty simple. Leave the MAF table and VE table stock.

Raise your max airflow and P ratio limits.

Don't add too much timing around peak torque.

You may have to desensitize your knock sensors some, they are pretty sensitive from the factory and the stock blower is noisy as hell, especially when you start spinning it faster.

I had to read this a couple of times. When I saw what Lambda you were suggesting to command I was thinking in my head FA Ratio. I kept thinking that is pretty lean for a boosted engine....but then I realized it was .xxx and not .0xx....that is when I realized it said Lambda. Guess that is what happens when you skim read while waiting for a flash to finish

[Jay@HAP]

sorry if I didn't explain it better.
Stoich FA .0722+ WOT FA .0170=.0892 FA

1.0 Lambda/.0892 FA=11.21 AFR

11.21/13.65=.82 Lambda, roughly

[mxatunerjg]

sorry if I didn't explain it better.
Stoich FA .0722+ WOT FA .0170=.0892 FA

1.0 Lambda/.0892 FA=11.21 AFR

11.21/13.65=.82 Lambda, roughly

Oh, you were fine....I just mis read your sentence. It said Lambda not FA Ratio....I just saw the numbers and was really confused until I realized it was Lambda. All my fault man.

[mrnorm_hemicide]

Side question: I see that the max voltage setting for both the main throttle body and the bypass throttle body is 5V, and is linearly positive for main throttle WOT and bypass closed... does anyone know if 5V is required for the main throttle plate to be truly WOT, and vice versa for the bypass to be fully closed? I currently have the peak value at 4.49V.

[06300CSRT8]

Doesn't need to be 5v to be completely open. Remember in the middle of the throttle body you have a "dead zone" equal to the diameter of the throttle blade mounting bar. Makes no difference in flow if the tip of the blade is in plane with the bottom of the mounting bar (4.49v) or the top of the bar (closer to 4.8v), motor will see the same flow, difference is going to 4.8v means now the blade has extra distance to move to close when you are off the throttle, for no reason.

[mxatunerjg]

Doesn't need to be 5v to be completely open. Remember in the middle of the throttle body you have a "dead zone" equal to the diameter of the throttle blade mounting bar. Makes no difference in flow if the tip of the blade is in plane with the bottom of the mounting bar (4.49v) or the top of the bar (closer to 4.8v), motor will see the same flow, difference is going to 4.8v means now the blade has extra distance to move to close when you are off the throttle, for no reason.

This is a perfect answer....I've tried so hard to explain this to so many people and everyone gets so stuck on it being perfectly flat. If the mounting bar was milled down to make it thinner, then there may be some amount of gain to be had, but unless racing in a series with limiting sizes on throttle body, why not just install a bigger throttle body? It would be less work, and less risk of breaking the milled mounting bar.

[mrnorm_hemicide]

So with the help of Jay, I think I got the fueling dialed in tighter.... that was the source of it pulling boost at the 1000ft mark on the first track session...

Went again last night, this time running MS109 fuel for added safety. Car only went 11.34 @ 125 mph. Granted my 60 ft was only 1.78 (running 20" MT ET Street R). I feel like my setup should at least trap faster? Am I leaving too much spark on the table? I also noticed that it is short shifting in drive (trans shifts around 5900 rpm, even though I have the limiter set at 6700).

I've attached the latest tune that I ran. Unfortunately my laptop crashed at the track, so no data log But I did get a data log this morning on the same fuel, same tune, on the street. However, this time I shifted it to see if it was still limiting me... looks like it only short shifts in drive

Anyone have any suggestions? Can I pickup some more power by upping the spark in the base tables?

[Jay@HAP]

You need to log Throttle Torque Source and your TM pids.

I noticed that you haven't licensed the TCM. There are RPM limiters and a couple other things in the TCM that is keeping it shifting at 5900 regardless you set your Engine RPM limit at.

[mrnorm_hemicide]

You need to log Throttle Torque Source and your TM pids.

I noticed that you haven't licensed the TCM. There are RPM limiters and a couple other things in the TCM that is keeping it shifting at 5900 regardless you set your Engine RPM limit at.

Throttle torque source is in the log file... further down the list of pids. When you say "TM", do you mean torque management? If so, what specific variables are of interest?

[Jay@HAP]

Throttle torque source is in the log file... further down the list of pids. When you say "TM", do you mean torque management? If so, what specific variables are of interest?

I see it now. Yeah it says RPM Limit, my guess it's hitting a Trans RPM Limit.

There are several TM pids. I would log all of them starting out.

You also have all of your TM enabled in the tune. You can play with turning some of them off to see if it helps you out down low.