changing injector dead time, what about VE? - Page 2 - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MEGAsquirt A place to collectively sort out this megasquirt gizmo

Reply
 
 
 
LinkBack Thread Tools
Old 05-21-2015, 01:59 PM   #21
Junior Member
Thread Starter
 
Join Date: Sep 2010
Location: Belgium
Posts: 77
Total Cats: -2
Default

Quote:
Originally Posted by 18psi View Post
This will sound corny, but: it's really about creating harmony between ALL the settings to get a good idle. Then it's about smoothing everything over and dialing in enough correction and buffer zone such that extremes (high power load, cold temps, ac kicking in, fans kicking in, etc) don't disrupt the idle and are compensated for timely and efficiently.

You need proper afr
You need proper timing
You need to pay attention to the cells AROUND both those areas too, they affect it
You need to do idle valve test to determine iacv range
You need to tune CL idle control settings, PID, and dashpots
You need proper AIT compensation
You need proper EGO correction settings
There's probably more I'm forgetting

A lot of this stuff gets overlooked
You're right about that, but I think most of that's covered. I've attached my tune a few posts earlier.
rpm is stable enough in my opinion but it's the vibration I want to get rid of...

I will post a log when idling, maybe you guys notice something wrong.

Thanks
miatadaxdriver is offline   Reply With Quote
Old 05-21-2015, 02:15 PM   #22
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,165
Total Cats: 2,573
Default

idle searching is very often caused by large variations between affected and surrounding cells. needs moar smoothing (but that's just a guess, I can't open your MSQ from work computer)
18psi is offline   Reply With Quote
Old 05-21-2015, 03:06 PM   #23
Junior Member
Thread Starter
 
Join Date: Sep 2010
Location: Belgium
Posts: 77
Total Cats: -2
Default

here you are
Attached Thumbnails
changing injector dead time, what about VE?-schermafbeelding-2015-05-21-om-20.04.26.png  
miatadaxdriver is offline   Reply With Quote
Old 05-25-2015, 12:13 AM   #24
Junior Member
 
Join Date: May 2015
Posts: 86
Total Cats: 10
Default

My experience with the 1.6 is that it's sensitive to injection timing at idle. You can smooth it out by changing end of injection timing in the idle area if you are sequential. Since you are batch fired you don't have that option.
arghx7 is offline   Reply With Quote
Old 05-25-2015, 11:04 AM   #25
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,814
Total Cats: 1,780
Default

<p>
Quote:
Originally Posted by miatadaxdriver View Post
here you are
</p><p>why arent you using idle VE table?</p>
Braineack is offline   Reply With Quote
Old 05-25-2015, 02:11 PM   #26
Junior Member
Thread Starter
 
Join Date: Sep 2010
Location: Belgium
Posts: 77
Total Cats: -2
Default

I would like to, but can't activate it right now I think...


Is this possible with MS2 firmw 3.3.3?
miatadaxdriver is offline   Reply With Quote
Old 05-25-2015, 02:23 PM   #27
Murderator
iTrader: (76)
 
18psi's Avatar
 
Join Date: Apr 2008
Posts: 36,165
Total Cats: 2,573
Default

I thought that was ms3 only
18psi is offline   Reply With Quote
Old 05-25-2015, 02:41 PM   #28
Sadfab Union President
iTrader: (3)
 
Join Date: May 2014
Location: Kansas
Posts: 2,690
Total Cats: 113
Default

You are correct, no idle VE cells outside the normal VE map in MS2.

I don't think 3.3.3 adds that feature either, but as a 3.3.2 user I'd sure like confirmation.
deezums is offline   Reply With Quote
Old 05-25-2015, 02:53 PM   #29
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,814
Total Cats: 1,780
Default

<p>no i was thinking ms3.</p>
Braineack is offline   Reply With Quote
Old 05-25-2015, 02:57 PM   #30
Junior Member
Thread Starter
 
Join Date: Sep 2010
Location: Belgium
Posts: 77
Total Cats: -2
Default

too bad, it's a nice feature in my opinion
miatadaxdriver is offline   Reply With Quote
Old 12-24-2015, 05:05 PM   #31
Junior Member
Thread Starter
 
Join Date: Sep 2010
Location: Belgium
Posts: 77
Total Cats: -2
Default

problem solved, bought a Link G4+
miatadaxdriver is offline   Reply With Quote
Old 01-05-2016, 09:58 AM   #32
Newb
 
Join Date: Sep 2015
Posts: 18
Total Cats: 0
Default

The fueling calculation is as follows:

PW = DT + (ReqFuel * MAP * VE[RPM,MAP] * AirDen * BaroCor * corrections)

Forget the corrections and we get:
PW = DT + (ReqFuel * MAP * VE)

Rearange the formula to find VE:
VE = (PW - DT)/(ReqFuel*MAP)

Assume we have 265cc injectors and a deadtime of 0.8ms, a required fuel value of 5.51 and want to find the PW at 80kPa with a VE of 55%:

PW = DT + (ReqFuel * MAP * VE)
PW = 0.8 + (5.51 * 0.80 * 0.55)
PW = 3.2244 m/s

We can rearrange to find VE as below:

VE = (PW - DT)/(ReqFuel*MAP)
VE = (3.2244 - 0.8) / 5.51 * 0.80)
VE = 0.55

Re scaling for new injectors example:
We upgrade to blue 540cc injectors, an assume a Required Fuel value of 2.25, and a dead time of 0.95

If we want to re-scale the VE table for new injectors we first solve to find the current PW (3.2244m/s in our example).
Then find the correction factor for the new injector. In our example using 265cc and 540cc injectors:

Correction factor = Old Injector cc min / New Injector cc min
Correction factor = 265 / 540
Correction factor = 0.4907

Applying this correction factor we find the new pulse width:

New PW = Current PW * Correction Factor
New PW = 1.58 m/s

Then we calculate the NEW VE value to populate our VE table as below:

New VE = (New PW - New DT)/(New ReqFuel * MAP)
NEW VE = (1.58 - 0.95) / (2.25 * 0.80)
New VE = 0.35 or 35%
RichieVee is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
In what world... curly MEGAsquirt 11 09-22-2015 12:54 PM
Interpreting Deatchwerks Dead Times from Battery Wizard compuw22c MEGAsquirt 0 09-14-2015 07:08 PM
VE values too low? compuw22c MEGAsquirt 4 09-12-2015 08:42 PM
First to get it out of the way main Meet and Greet 1 09-05-2015 01:39 PM
ME221 Now has Autotune and Long Term Fuel Trim Tables Motorsport-Electronics ECUs and Tuning 0 09-05-2015 09:02 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 11:39 AM.