2009 Cobalt SS TC (LNF) - Boost limited to 22.4 psi??

[metroplex]

1. What turbo are you running that you think you can hit 28psi at 2800rpm?
2. If you are looking at the intake manifold sensor, it maxes out and you won't see anything higher.
3. I am 99% sure you are logging something incorrectly.
4. It doesn't look like you are logging much of what you should be logging (this is separate of boost).
5. (Previous post you had) fuel pressure has nothing to do with PSI from the turbo.

1). I'm not trying to hit 28 psi. I'm just saying that the table (stock) allows for up to 28.84 psi at 2800 RPM, yet I am actually hitting 22.4 psi / 25 psi at that RPM and it's a limit of some sort (not a curve). Basically, I'm hitting 22.4 psi or 25 psi at points where the Pressure Table RPM allows for 27-29 psi. I'm just looking at the table you recommended I examine.
2). Using the Intake Manifold sensor, the boost peaks out at 22.4 psi. Using the Boost Lo Res sensor, the boost peaks out at 25.x psi (about 3 psi higher but same "curve" as Intake Manifold Sensor). Looking at my EcoBoost 3.5 data, I'm not hitting the same ceiling for boost as it flows up/down slightly (9-11 psi) whereas with the LNF it is basically pegged across the board.
3). For boost, it seems elementary unless I am missing something. I'm logging Boost Lo Res and subtracting Atmospheric Pressure from that reading. kPa, PSI, or inHg it's the same calculation.
4). I'm logging knock retard, spark advance, fuel trims, RPM, airload, throttle, etc... and the usual stuff I use to log and tune my Fords. I'm trying to find the LNF E69 video that shows what the other people use for datalogging. I had the HPTuners config file that someone posted about 3-4 years ago here, but I don't have it anymore. I'll keep trying to find it.
5). I was looking at fuel pressure because it was odd that it is pegged at the max, along with boost. I figure if the fuel pump is peaked out, then the ECU won't allow more boost/air. I'm just trying to understand how it works.

[metroplex]

I just watched the 30 min video on Youtube. I used that same configuration 3 years ago and changed it for VCM 3. The only thing I wasn't using was the waste gate histogram which he based on load vs RPM but the waste gate dc table is desired boost % vs RPM. I'm not sure what his thought was for that table. I'm logging most of the same things just not putting then on the graph output.

[MikeM173]

I completely understand you are trying to learn, and I wasn't trying to say you were completely jacked up, so I hope it didn't come across like that. I'm a bit busy, and texting works better for me. I still have to upgrade my software to 3.0 and get a good log file going for it, but I am going to inbox you my number. I can explain all of this and have you understanding everything you are asking in this thread. The PSI vs KPA discussion is nothing. It is just a preference of mine. That doesn't mean you are wrong, I'm just not used to looking at that because every time I do, I look at KPA. That's all I was trying to get at.

[cobaltssoverbooster]

The calculations look fine (about 2.5 * 14.7 psi) more than enough ceiling for boost?
I'm curious why the boost hits a ceiling at around 25 psi, but the fuel pressure is maxed out at the same point (flat line for boost and fuel pressure).

your max limits are determined as such: [14.69*(pressure rpm table value)] - 14.69
therefore at 5,000 rpm 22.76 psi will be all you can achieve.

[metroplex]

your max limits are determined as such: [14.69*(pressure rpm table value)] - 14.69
therefore at 5,000 rpm 22.76 psi will be all you can achieve.

So how come I am limited to 22.4 psi / 25 psi at 2800 RPM when the Pressure Table says I can achieve up to about 29 psi?

[califcarm]

So how come I am limited to 22.4 psi / 25 psi at 2800 RPM when the Pressure Table says I can achieve up to about 29 psi?

The 22.4 is the max reading (255kpa) the ECU will accept from the upper manifold map sensor. It will never register above that. The software is just coded that way for some reason. So you can ignore the reading from the manifold map when you reach 255kpa or above and must look only to the boost lo res sensor.

I might guess you just don't have enough WG duty cycle (combined with DAL) to generate more than 25 psi (your actual pressure from boost lo res?), or the turbo might not be physically able to generate more than that until a little higher rpm (I am new to LNF's and K04's)? I think the Ford's you are used to have a little more engine displacement (2.3L?) and will spool a turbo a bit earlier than on the LNF? (I replied with more detail in the cobaltss thread you started).

What boost do you hit at 3500 rpm for example?

[metroplex]

The Boost Lo Res sensor is about 3 psi higher than Manifold MAP, I am hitting 25 psi across the board. At 3500 RPM, I'm at 24.89 psi but it looks like it hit a ceiling. Here's a screenshot that shows Boost Lo Res. It basically hovers between 24-25 psi until I let off the throttle.

The EcoBoost I was datalogging is the EcoBoost 3.5L V6 from my SHO, it was between 9-11 psi max (twin Garret GT15 turbos) but I could monitor actual throttle angle and the torque limiters prevented full opening of the blade (it was about 50% when my pedal was 100%).

[cobaltssoverbooster]

if you capped out it would be flat...not the case in your screen shot

[metroplex]

The only time it started to dip down was when I started letting off the throttle. When I was actually WOT, the boost was very steady. I'm fine if that screenshot looks normal, because 25 psi is probably more boost than I need with the stock K04.

[Area47]

oe sensors will read up to 22.93 psi. pressure vs rpm factor. max air load. my money is on you runing a lot higher boost levels due to the factory sensors limitations.

[califcarm]

The Boost Lo Res sensor is about 3 psi higher than Manifold MAP, I am hitting 25 psi across the board. At 3500 RPM, I'm at 24.89 psi but it looks like it hit a ceiling. Here's a screenshot that shows Boost Lo Res. It basically hovers between 24-25 psi until I let off the throttle.

The EcoBoost I was datalogging is the EcoBoost 3.5L V6 from my SHO, it was between 9-11 psi max (twin Garret GT15 turbos) but I could monitor actual throttle angle and the torque limiters prevented full opening of the blade (it was about 50% when my pedal was 100%).

I agree that you don't seem to be "capped out" in a sensor, as that would peg the sensor and it would not vary at all. Not a 24-25 kind of thing, it would stay exactly the same. You can see that if you log your manifold map at over 255kpa (over 22.5 psi approximately). It would just continue reading 255kpa no matter how much higher your boost goes.

For you difference in manifold map to boost lo res of 3 psi, you say that exists at all boost levels, even below 22.5psi? (should read pretty much the same at WOT especially in the 15-22psi range, so something like an offset for those sensors is out if you have a 3 psi difference everywhere).

You are correct that not many people from my limited research think there is much to be gained by going for more than 25psi on a K04. In fact you are not going to hold 25 psi to redline any way as the turbo/wastegate combination won't do it in stock form. As for hitting 25psi if you wanted to, I just don't think you have enough DAL/WG duty cycle to get there in the lower rpm at a quick guess.

Is your Max WG duty cycle setting (the singular value that is not in the table) still set at GMS1 of 95%? If so, you can increase that and for me it seemed to increase what all WG duty cycle setting delivered for boost that are inside the table: ie: 90% WG duty in the table with 100% WG max setting delivered more boost than 90% WG duty in the table with 95% WG max setting. It's how I hit 29 psi accidentally, as I had my table setup to deliver about 23 psi and then changed WG max from 95 to 100%. So if you do change the max setting be careful to lower your high load WG table values down quite a bit and inch them back up to desired boost.

[metroplex]

The Max WG DC is still at 95%. If I'm really running 25 psi now, I think I'll keep the WG settings the same. I'm going to look at reducing the torque for 1st and 2nd gear, because the car is pretty much undriveable during a hard launch.

[ECaulk]

oe sensors will read up to 22.93 psi. pressure vs rpm factor. max air load. my money is on you runing a lot higher boost levels due to the factory sensors limitations.

Going to go ahead and quote this post. Since I'm fairly certain Area has the OPs issue highlighted.

[califcarm]

I think the OP is running the 3bar GMS1 sensors and has adjusted his parameters for it already. (so he does indeed show over 23psi on the boost lo res).

[metroplex]

Yes, that's right. I have both 3-bar MAP sensors from the GMS1 kit. I'm going to change the Pressure RPM table anyhow. What I'm going to do with the torque limiters is reduce the stock 1st gear limiter by another 5%, copy the stock 1st gear limiter to 2nd gear but increase by 25%. Only one way to find out how it goes...

[TurboCobalt]

I keep reading this again and again all over the place and i have to say something.
the manifold pressure sensor (3 BAR sensor in th OP's case) can read up to 3 bar absolute pressure, assuming the OP changed the calibrations to read the sensor correctly the controller can read that high. The problem is not the sensor or the controller reading the sensor, the limiting factor is the MAP PID that has a limited resolution and has a maximum read out of 255kPa, when you pay attention to the SI units, 255 is a very evident number, 8 bits, or hex 0xFF, however u want to read it, again, the controller READS THE RIGHT VALUE, internally, but the MAP PID you record is the limitation. the MAP PID saturates, it has a ceiling, of 255kPa. you can convert that into PSI if you want, but still same thing, it'll have a maximum possible value.
Now, 2 pages into this tread OP, do as every good poster here has recommended and read the Boost Low Res PID, which is a lower resolution, but higher maximum, to determine your true boost pressure. (why are we still debating this after so many people told you what to do.)

This has nothing to do with your fuel pressure, completely separate systems, I notice you keep going back to that fuel pressure thing. also log Fuel pressure desired, AND fuel pressure measured.

Also, anybody going to mention that the DAL's are unnecessarily high for a stock turbo ?

[metroplex]

Thanks. Since I already log Boost Lo Res, if you read some of the older posts you will see that I've already posted the data. It is basically 3 psi more than reading the Manifold MAP (So 22.4 psi for Manifold MAP, 25.4 psi for Boost Lo Res). I just had to create a new Maths parameter since the data was already there.

It was explained that the ECU is hard coded to read the manifold MAP up to 22.4 psi even with the GMS1 tune and 3-bar MAP sensors. If you looked at some of the screen shots I've posted, I'm running the GMS1 settings for everything. Doing a comparo with the Delta and Kappa GMS1 files, the sensor settings are the same.

For the DAL's, I'm going by what BYT posted in an earlier guide. I haven't found any newer guides that explained better settings for DAL. It seems everyone that tunes their LNF has a different opinion on how DAL correlates to boost. One of them was that the numbers are in kPa and subtracting 101 kPa (atm) gives you the desired boost. If you have a better idea, please do share. It looks like I'm reaching about 240%+ max airload from the data I could gather.

Whatever the case, I think holding 25 psi is good enough unless someone out there objects or sees something blatantly out of place. I'm not out to push the envelope of my SS/TC, just trying to make it run a bit spicier than stock. The front tires light up in 1st and 2nd gear too easily, so I'm going to have to play around with the torque limiters for those 2 gears. It is fine in 3rd.

As for fuel pressure, I only mentioned it in the beginning because it was practically flat lined at the max with 25 psi of boost. As for desired vs actual, I just wanted to look at the actual fuel pressure for now. On the EcoBoost 3.5L V6, I was told that the direct injection high pressure fuel pump is the limiting factor. The engine and stock turbos can make more power, but the pump would run out of fuel and would be evident with low fuel pressure readings.

[ECaulk]

I thought someone mentioned the high DALs earlier. Another thing I just noticed on his screen shot log, why are you starting your log pull around 2,000rpm?

Also OP are you asking why you're not seeing higher than 25psi boost? (~273kPa)

[ECaulk]

How much air are you flowing from the MAF reading towards the top of the rpm range (5750-6250)?

[ECaulk]

I think you just read a few of the first posts and decided to chime in. Since I already log Boost Lo Res, if you read some of the older posts you will see that I've already posted the data. It is basically 3 psi more than reading the Manifold MAP (So 22.4 psi for Manifold MAP, 25.4 psi for Boost Lo Res). This was addressed awhile ago. I just had to create a new Maths parameter since the data was already there.

It was explained that the ECU is hard coded to read the manifold MAP up to 22.4 psi even with the GMS1 tune and 3-bar MAP sensors. And yes if you looked at any of the screen shots I've posted, I'm running the GMS1 settings for everything. Doing a comparo with the Delta and Kappa GMS1 files, the sensor settings are the same.

For the DAL's, I'm going by what BYT posted in an earlier guide. I haven't found any newer guides that explained better settings for DAL. It seems everyone that tunes their LNF has a different opinion on how DAL correlates to boost. If you have a better idea, please do share.

Whatever the case, I think 25 psi is good enough unless someone out there objects or sees something blatantly out of place. I'm not out to push the envelope of my SS/TC, just trying to make it run a bit spicier than stock.

As for fuel pressure, I only mentioned it in the beginning because it was practically flat lined at the max with 25 psi of boost. As for desired vs actual, I just wanted to look at the actual fuel pressure. On the EcoBoost 3.5L V6, I was told that the direct injection high pressure fuel pump is the limiting factor. The engine and stock turbos can make more power, but the pump would run out of fuel and would be evident with low fuel pressure readings.

We can't see if anything is blantantly out of place if you don't upload the tune for us to look at. Also the pressure of the fuel pump does matter to a point, but it's not the limiting factor if you're meeting the demand. Assuming you're running pump fuel I'm sure you are not near maxing out the injector window for the LNF, I've never looked at a tune file for a 3.5l Ecoboost, nor do I know anything about their fuel pumps or injectors.