[billnchristy]

I need to sit and really do some screengrabs to prove all this but here's my theories:

1) we don't have a fuel problem stock, would need modified logs but I bet you're seeing similar
When on boost the system never leans and trims fuel as much as 16% that should mean that's your window on modifications plus buffer
2) the super lean condition off throttle is intentional as the system defaults to 0 trim when either the system calls for lean or the calculated is there. It's as if the computer allows the actual a/f to mismatch for a full second before agreeing.
3) at idle trims are super positive but a/f is generally around standard. I think the system runs lean for economy here as there is no threat of boost just coming on
4) there is a legit 1 second delay from throttle open to response

[billnchristy]

Added timing to my logs and am happy to say that it continues to advance even at full boost or nearly, only hit 20.7 but between 14.5 and 20.7 it advanced another 1.5 degrees and isn't pulling timing.

Found a spot at 22.7 and it dropped another degree but still 5 advanced

[xcelir8bmw]

Not literally, but I had a bug up my butt last night thinking, pondering, and looking back at the last month of trials and tribulations on R&D, etc.

1. I spent quite a bit of time with bright lights in my garage and flashlights and mirrors, looking at the entire engine and noodling in my head comparing to what I did to the STI.
   
2. Maybe I was a little miffed because a few YouTube videos I was watching about BMWs and the use of 'plastic' in the engine bay for major components and their durability and reliability.
   
3. In comparison of old EJ STI engines compared to the new BMW engines, the basis of forced induction and use of plastics were similar. However, I did notice that there were crimp-style bands rather than worm-style bands in some places and was a bit surprised at that.
   
4. Also, the packaging in this vehicle is a bit tighter (not dramatically by much) than the STI.
   
5. Relatively speaking, everything is so similar at the core system.
   
6. Why do I care? Well, I didn't plan on buying this car and doing a shit ton to it like the STI. Nope. Didn't even phase me. I kind of wanted to be done with 'how much I wrench' on a car at this point, but having the capability is always good.
   
7. I added the fake Carbon Fiber on the inside, a dash cam, a radar detector, additional Qi charger, dragy, and a boost gauge. As well as a 12V battery tender lead in the engine bay. I've done a very good job and it's all very clean and good.
   
8. And then for performance, finalized on the JB4, with the pedal tuner removed.
   
9. I just wanted to do 'a little more' to smooth out the rev band if possible - so we'll see what the Pipercross filter does.
   
10. Thinking more about this discertation, and as the market matures, I could easily see someone spending probably five grand for some 'package of sorts' to include an intake, downpipe to muffler tip exhaust system, fuel delivery, and a good ECU tune. I didn't really want to go there, monetarily, but mentally I have.
    
11. So where does this lead me?
    
12. Post Pipercross filter R&D - I am stopping this endevor and trying to curb my 'addiction'.
    
13. However, I do want to understand, what is behind everything to know the art of the possible.
    
    

P.S. Below is some of the past cars that I have owned, not including two current civics, a fit, a minivan, and the bimmer.

[billnchristy]

Here's a graph of a 12 second basically full throttle run

[//TMT]

Originally Posted by billnchristy

2) the super lean condition off throttle is intentional as the system defaults to 0 trim when either the system calls for lean or the calculated is there. It's as if the computer allows the actual a/f to mismatch for a full second before agreeing.

It's certainly intentional. But it's not the trim. When off the throttle and moving, the DME shuts off the injectors and cranks the valve timing. Basically it runs the engine like a closed air compressor - adiabatically. Then it energizes the alternator and attempts to soak up energy.

You can see this on the dashboard - the red economy meter swings to way over 40, and shortly after that, the blue energy recovery bar lights up. If you're displaying instantaneous fuel economy, it will go sky high.

[rice_rocket88]

So after the weekend I just put on the stock box, same half tank of the same fuel. It's much colder today at 55F and raining. Now other than thinking the BMW has other fancy programming to reduce boost or timing (ie windshield wipers on or anything like that)... I didn't see any boost over 27, nor any lean conditions. No matter how hard I could beat it on map 2,6 or 0.. nothing will failsafe which is nice. Surprised that air intake I made could suck that much more air in or make it that much more boost happy (and lean out the fuel).. what do you think?

Oh.. and while I was putting together the stock box, I popped out the X1's air filter. It is very similar, but one corner notch is taken out of the m35i and it's slightly larger.. so unless the m35i shares more parts with other b48's then maybe they did need more air flow than the X1\X2 28i engines.. seems like a waste to make such small adjustments in production rather than reuse the same parts.

Also got me thinking that I did not have to chop up my snorkel like xcelir8bmw so bigger diameter piping and maybe a faster flowing filter made my car gulp tons more air. I don't see how heat soaking could cause issues of leaning out at all, rather it would be the opposite. Besides, now that I'm looking at my logs from Friday, I have the same IAT temps as today. And Today is colder outside with the stock box.. so when the car is going, my intake seems to be seeing the same temp air on the highway.

[xcelir8bmw]

Originally Posted by rice_rocket88

I didn't see any boost over 27, nor any lean conditions. No matter how hard I could beat it on map 2,6 or 0.. nothing will failsafe which is nice. Surprised that air intake I made could suck that much more air in or make it that much more boost happy (and lean out the fuel).. what do you think?

So what I am reading is that you proved that you are experiencing EXACTLY the same conditions of after-market intake versus stock box as I have.

Told you so. LOL.

Massive air flow requiring more fuel. It makes sense - just the amount is crazy, but not - cause our fuel pumps are not more than 200lph which I wish they were at least 250lph.

Now let's see what the Pipercross filter does.

[rice_rocket88]

It is possible.. Terry said that the BMW program runs load based, so because of the colder temp (55F) it is a lower boost target.

It still doesn't explain why I could run map 6 really hard and not have issues until the latest update. Map 1 and 2 always hit boost failsafe (but then I was at 27psi). so.. yes and no?

[xcelir8bmw]

Originally Posted by rice_rocket88

It is possible.. Terry said that the BMW program runs load based, so because of the colder temp (55F) it is a lower boost target.

It still doesn't explain why I could run map 6 really hard and not have issues until the latest update. Map 1 and 2 always hit boost failsafe (but then I was at 27psi). so.. yes and no?

What's your safety at? 30?

And map 6 was 'programmed with what values? That's a 'custom' map.

[rice_rocket88]

My Safety is at 30 now, but prior to the firmware update I was running the custom map 6 with a "1" boost additive which net me just over 27psi and never hitting any failsafe all year. After the last firmware update I could hit failsafe on the custom map which confused me since nothing else was changed. This is also why I wanted to get a new tank of fuel to see if things would go back to normal. Seeing as I'm only at half a tank of gas, I decided to throw the stock box on for this week to see what happened.. and the result is that I can push the car as hard as I want on any modes without issues.

Still next gas fill up I'm going to put my intake back on to see what happens..

[billnchristy]

Given what I have seen with my logs, I don’t think you’re going lean, I think you’re freaking the computer out. It’s calling for fuel trim, afr, timing at say 19lb because that’s what the jb4 is telling it, but the reality is different and while there is room to run 27lb of boost, there isn’t when several pounds less are telling the computer the wrong story.

[rice_rocket88]

Right I understand what you're trying to say.. we need someone with more tuning knowledge to help out here.. you'd think that JB4 would be changing all the rest at the same time they are fooling the boost. There are no logs to actually see how much more the MAF is seeing with these intakes. I did not hear any new emails back from Terry about my direct question on use of the intake or if anything can/should be adjusted. I'm still going to continue until I get to the next tank of citgo, exxon, shell,or mobil (the top tier stations near me)

[xcelir8bmw]

Terry told me no JB4 changes to be made to support aftermarket intake.

[xcelir8bmw]

Originally Posted by billnchristy

Given what I have seen with my logs, I don't think you're going lean, I think you're freaking the computer out. It's calling for fuel trim, afr, timing at say 19lb because that's what the jb4 is telling it, but the reality is different and while there is room to run 27lb of boost, there isn't when several pounds less are telling the computer the wrong story.

I think you are right.

[xcelir8bmw]

JB4 Boost vs. DME Boost and other Logging..

Compare and contrast the two plotted graphs I provided:

Boost/DME Boost is about equal in comparison.
AFR is about equal in comparison.

TRIMS is where it wigs out!

[//TMT]

Originally Posted by xcelir8bmw

TRIMS is where it wigs out!

What exactly is being logged for TRIMS? Is that purely STFT, or some kind of composite?

STFT can be pretty variable, especially when driving hard. I wouldn't worry about it too much, in isolation. If correlated with other issues (AFR, knock, whatever) then maybe more important.

[billnchristy]

Do you have regular obdii scanner? I can read maf.

It's going to try to reach afr number with stft and timing. On mine I have significant room, 5 degrees advance and another 10% trim at max boost. I would think that would be enough to handle another 2-3lb and technically you could retard timing a bit but that would go against making power.

I did research last night, we have the same hpfp as supra and it's good to 800hp. We have same injectors as xm5 which is good to about same.

I could not find data on the b58 lpfp

[xcelir8bmw]

Honestly think it is something of a piggy back vs. a real tune. The two systems, DME and piggy back are not working together IMO.

[billnchristy]

I talked to a tuner, they stopped tuning b48 because they were melting pistons.

He suggested that the dme may be getting torque limit signals from the transmission which is causing your cuts and failsafes

[rice_rocket88]

That's another interesting variable...

[Davy Jordi]

melting pistons? damn.

[xcelir8bmw]

Damn.