Pages: [1]
Author Topic: MAF 3" and flow stopped on 262 g/s  (Read 7053 times)
krzysiek50
Newbie
*

Karma: +0/-0
Offline Offline

Posts: 6


« 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?
« Last Edit: November 04, 2019, 10:56:37 AM by krzysiek50 » Logged
fluke9
Full Member
***

Karma: +26/-1
Offline Offline

Posts: 113


« Reply #1 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?
Logged
Blazius
Hero Member
*****

Karma: +89/-40
Offline Offline

Posts: 1282



« Reply #2 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.
Logged
RBPE
Sr. Member
****

Karma: +40/-5
Offline Offline

Posts: 395



« Reply #3 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.
Logged
krzysiek50
Newbie
*

Karma: +0/-0
Offline Offline

Posts: 6


« Reply #4 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.
Logged
_nameless
Hero Member
*****

Karma: +342/-466
Offline Offline

Posts: 2802



« Reply #5 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
Logged

Giving your mom a tuneup
fluke9
Full Member
***

Karma: +26/-1
Offline Offline

Posts: 113


« Reply #6 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 ;-)
Logged
Blazius
Hero Member
*****

Karma: +89/-40
Offline Offline

Posts: 1282



« Reply #7 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.
Logged
krzysiek50
Newbie
*

Karma: +0/-0
Offline Offline

Posts: 6


« Reply #8 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.
Logged
nyet
Administrator
Hero Member
*****

Karma: +608/-168
Online Online

Posts: 12270


WWW
« Reply #9 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.
Logged

ME7.1 tuning guide
ECUx Plot
ME7Sum checksum
Trim heatmap tool

Please do not ask me for tunes. I'm here to help people make their own.

Do not PM me technical questions! Please, ask all questions on the forums! Doing so will ensure the next person with the same issue gets the opportunity to learn from your ex
Kompiesto
Full Member
***

Karma: +4/-5
Offline Offline

Posts: 109


« Reply #10 on: March 31, 2020, 12:12:49 AM »

MLMAX = 1000kg/h.
Logged
Pages: [1]
  Print  
 
Jump to:  

Powered by SMF 1.1.21 | SMF © 2015, Simple Machines Page created in 0.023 seconds with 17 queries. (Pretty URLs adds 0.001s, 0q)