DIY tuning

Stokes

Corporal
Jan 26, 2018
225
Houston, TX
I uploaded a log to Datazap (in case that's what you meant, if not I can upload it somewhere else). Any feedback would be appreciated. I'm also going to try to make the contact you sent me, hopefully today.

Oh Geez. I can't remember how the JB4 parameters go, they are so weird to me. Trims start dropping and so does FP_H, so my first though (might be way wrong) is that you are asking for less fuel in the upper end. My experience has been the hpfp gets taxed the most mid range, not at the top end of gear. Maybe someone else more intimate with JB4 logging can help. Also, I've found the settings on the JB4 side make a huge difference as they are inline hijacking the signals to fuel rail and MAF.
 

JPuehl

Lurker
Jul 24, 2019
19
Greater Seattle area
Oh Geez. I can't remember how the JB4 parameters go, they are so weird to me. Trims start dropping and so does FP_H, so my first though (might be way wrong) is that you are asking for less fuel in the upper end. My experience has been the hpfp gets taxed the most mid range, not at the top end of gear. Maybe someone else more intimate with JB4 logging can help. Also, I've found the settings on the JB4 side make a huge difference as they are inline hijacking the signals to fuel rail and MAF.
Houtan mentioned the same about the HPFP NOT getting taxed on the upper end. The Fuel_OL value, which is the only "fuel" related user adjustable value, is supposed to be a bias applied to what the DME is seeing for the actual pressure, the higher the user value, the lower that is "reported" back to the DME in an effort to make the DME raise pressure. A "trims" value of 25 is supposed to mean no added trims help to the HPFP, above 25 is more "help" and below is less, so it seems if my HPFP values drop <11 then the trims should be increasing even if the HPFP can't meet demand, not decreasing as seen in the log. Also my AFRs from about 4400 rpm on are ~12, which might be too low, so it seems demand is high. I could try raising the AFR in areas and see how it runs (just could use some guidance as to what I should be shooting for, besides not causing misfires lol).

Now that I think about it, with HPFP not getting taxed on the upper end yet an obvious downward sloop of trims can be seen in the log, perhaps the trims are causing the pressure to drop <11 and causing the misfire? Right around a trims value of ~26 is where the HPFP value drops below 11, even though timing and AFRs are OK.
 

Stokes

Corporal
Jan 26, 2018
225
Houston, TX
I missed where you were getting misfires. What fuel are you running? AFRs look fine enough for 93. I found Ethanol has a different target, usually leaner. Some like 12.5.

If I would drop under 12.1 on E30 I'd get that misfire feel or if rail pressure dropped below 1700 psi.

Looks like 6 degree of timing pull on #4 from 5800 on. That's not good. Oh, and earlier around 4k. Might want to verify coil/plug first before chasing a HPFP issue. Man, if that is 93 fuel, that might be too much timing for the 20 psi mid range. I'd play it safe and get correction out of there as a first step.

This is why I didn't like the BEF tunes. They were super aggressive it seemed and everyone with the JB4 were fine with corrections all over the place and "as long as your avg ignition value is low, you can crank up the boost!" I don't follow that belief.
 

JPuehl

Lurker
Jul 24, 2019
19
Greater Seattle area
For my fuel I'm running 92 pump with enough Boostane to make a "calculated" 98 octane. I'd love it if my timing was consistent across all cylinders but 1 in 5 logs has matching timing. This log it will be #4 correcting, next log it will be #2 and #6 then next log... I have my doubts about the accuracy of the JB4 logs. How can 1 cylinder have -4* correction and the cylinder next to it have +8*? That doesn't make sense. And I've made adjustments to the AFRs and timing int he BEF so it's not exactly as it was when I downloaded it from the N54tech site.
 

RealM135i

New Member
Jul 29, 2020
3
Guys

On the:
Compressor/ turbine characteristic table
Wastegate position model
Wastegate feed forward tables
And every other table under the boost section

Is the MAF axis values the MAF req WGDC logging value or just the normal MAF logging value?
 

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