|
Title: MAF 3" and flow stopped on 262 g/s Post by: krzysiek50 on November 04, 2019, 10:54:29 AM Hi. I have VR6 turbo (AUE, 022906032E) and problem with MAF. In logs flow stopped everytime on 262 g/s, but in MLHFM max flow is rated to 310g/s. Voltage measured at MAF output is 5V on 1bar boost, however at 262 g/s voltage should be about 4,76V. WTF? Do i need remove some limitter in bin file?
Title: Re: MAF 3" and flow stopped on 262 g/s Post by: fluke9 on November 08, 2019, 12:43:36 PM Are you sure you measured the output of the MAF, not the supply voltage ?
When does it actually hit like 4.5 Volts ? Is this a Stock MAF or bigger one? Title: Re: MAF 3" and flow stopped on 262 g/s Post by: Blazius on November 08, 2019, 05:01:29 PM im pretty sure you need to take the 200kg/h offset in the max maf limit maps , if its a Bosch one.
Title: Re: MAF 3" and flow stopped on 262 g/s Post by: RBPE on November 09, 2019, 06:46:05 AM Unless you're running custom code for boost/post ambient pressures, you haven't underscaled the HFM to cater for it.
Title: Re: MAF 3" and flow stopped on 262 g/s Post by: krzysiek50 on November 12, 2019, 09:59:12 AM Are you sure you measured the output of the MAF, not the supply voltage ? When does it actually hit like 4.5 Volts ? Is this a Stock MAF or bigger one? Yes, i'm sure, it was ~5,05V on output. This is stock 3" MAF. im pretty sure you need to take the 200kg/h offset in the max maf limit maps , if its a Bosch one. Now offset is equal 200kg/h. You can see this in my bin file. Unless you're running custom code for boost/post ambient pressures, you haven't underscaled the HFM to cater for it. What do you mean talking about underscaling HFM? I have stock MAF and stock KLHFM (only for idle is slightly corrected). Do you think changing to bigger housing and underscaling KLHFM will help? Can you take a look on my file? Maybe you find what is wrong, because i don't have any ideas. Title: Re: MAF 3" and flow stopped on 262 g/s Post by: _nameless on November 12, 2019, 10:04:26 AM im just going to throw it out there with vrts ive always seen the maf stop flowing around 4.7v. underscale and use a larger housing or find the load caps and use a larger housing with more realistic scaling
Title: Re: MAF 3" and flow stopped on 262 g/s Post by: fluke9 on November 13, 2019, 04:33:50 AM im just going to throw it out there with vrts ive always seen the maf stop flowing around 4.7v. underscale and use a larger housing or find the load caps and use a larger housing with more realistic scaling Thats why i asked, according to the specs they should ceil at ~4.5v not 5v. 5,05v sounds more like the supply not the output. For my supercharged 3.0 GTV with a really old Motronic only used for igniton (Megasquirt for fuel) i had to limit the hot air MAF output otherwise the Motronic would drastically retard ignition or even cut it. My superhackish but nicely working solution was to put a diode with ~0.4v forward voltage in series, which also resulted in a bit retarded igniton but still got really really nice dyno figures ;-) Title: Re: MAF 3" and flow stopped on 262 g/s Post by: Blazius on November 13, 2019, 11:27:27 AM 200 kg/h = 55 g/s , as I said, you are simply hitting maf limit ,unless underscaled or other things. If you look for other max airflow maps they always 200kg /h than it actually is
some people had this "issue" before too on the forum. Title: Re: MAF 3" and flow stopped on 262 g/s Post by: krzysiek50 on November 13, 2019, 11:22:35 PM 200 kg/h = 55 g/s , as I said, you are simply hitting maf limit ,unless underscaled or other things. If you look for other max airflow maps they always 200kg /h than it actually is some people had this "issue" before too on the forum. Change offset to 0? I understand that offset is a limitation to getting a full airflow reading. Title: Re: MAF 3" and flow stopped on 262 g/s Post by: nyet on November 14, 2019, 12:02:41 AM Change offset to 0? I understand that offset is a limitation to getting a full airflow reading. No, that is insane. Offset is there to support MAFs that can report negative flow. The limitation here is the voltage. Use a larger housing if you are anywhere near 4.7v This has literally nothing to do with offset. Title: Re: MAF 3" and flow stopped on 262 g/s Post by: Kompiesto on March 31, 2020, 12:12:49 AM MLMAX = 1000kg/h.
|