MSPNP MSPNP specific Megasquirt related discussion.
Sponsored by:
Sponsored by:

Repurposing MSPNP9495 EBC Output Pin for VICS

 
Old 05-04-2014, 10:48 AM
  #1  
Elite Member
Thread Starter
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 6,169
Total Cats: 655
Default Repurposing MSPNP9495 EBC Output Pin for VICS

Planning to repurpose the EBC output for the OEM VICS solenoid on a normally aspirated car. Anyone know if the MSPNP9495 circuitry will be OK with the solenoid? Ben?
hornetball is offline  
Old 05-05-2014, 11:47 AM
  #2  
Supporting Vendor
 
Matt Cramer's Avatar
 
Join Date: Sep 2006
Posts: 2,329
Total Cats: 62
Default

Sure, the circuit can sink plenty of current.
__________________
Matt Cramer
www.diyautotune.com
Matt Cramer is offline  
Old 05-05-2014, 12:32 PM
  #3  
Elite Member
Thread Starter
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 6,169
Total Cats: 655
Default

Thanks Matt.
hornetball is offline  
Old 05-19-2014, 06:43 PM
  #4  
Elite Member
Thread Starter
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 6,169
Total Cats: 655
Default

I'm almost there . . . everything's wired up and ready.

I set X4 function to Output1. No sweat.

Now I go to the Outputs dialog to setup Output1. It wants the value as a raw byte (0 to 255) even when I setup RPM as the source. Anyone know the conversion from RPM to the raw byte?

Sorry for being an MS1 dinosaur, but the 1st gen MSPNP came with the car.
hornetball is offline  
Old 05-20-2014, 09:24 AM
  #5  
Boost Czar
iTrader: (62)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 76,387
Total Cats: 2,295
Default

why not use the EBC function, and just populate the rpm/tps duty table to go from 100% to 0% at 5252RPM?
Braineack is offline  
Old 05-20-2014, 09:27 AM
  #6  
Elite Member
iTrader: (3)
 
concealer404's Avatar
 
Join Date: Aug 2011
Posts: 10,265
Total Cats: 1,607
Default

Originally Posted by Braineack View Post
why not use the EBC function, and just populate the rpm/tps duty table to go from 100% to 0% at 5252RPM?


Does it react that fast? (Genuinely don't know, just asking)

Will the EBC function work properly with signal ground? Thought it worked via 12v pulse. (Again, genuinely asking)
concealer404 is offline  
Old 05-20-2014, 09:41 AM
  #7  
Elite Member
Thread Starter
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 6,169
Total Cats: 655
Default

Originally Posted by Braineack View Post
why not use the EBC function, and just populate the rpm/tps duty table to go from 100% to 0% at 5252RPM?
Because I'm retarded.

Darn good idea. Will do.
hornetball is offline  
Old 05-20-2014, 09:45 AM
  #8  
Elite Member
Thread Starter
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 6,169
Total Cats: 655
Default

Originally Posted by concealer404 View Post
Does it react that fast? (Genuinely don't know, just asking)

Will the EBC function work properly with signal ground? Thought it worked via 12v pulse. (Again, genuinely asking)
Yes, instantaneous (or as instantaneous as a PN junction in a transistor can be).

The circuit, whether you're using it to PWM an EBC solenoid or as a simple discrete output, provides either an open-collector (i.e., no continuity) or ground. That's why you supply switched 12VDC to the other side of the device (normally the other side of the EBC solenoid . . . in this case the other side of the VICS solenoid).
hornetball is offline  
Old 05-20-2014, 09:56 AM
  #9  
Elite Member
iTrader: (3)
 
concealer404's Avatar
 
Join Date: Aug 2011
Posts: 10,265
Total Cats: 1,607
Default

Ah ok that makes sense. I learned a thing today!
concealer404 is offline  
Old 08-06-2014, 03:45 PM
  #10  
Elite Member
Thread Starter
iTrader: (3)
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 6,169
Total Cats: 655
Default More info

I followed Brainy's logical suggestion to use the open loop EBC function for VICS control. The idea is that this would let me make use of the built-in RPM settings. This is how I set that up:






By setting my targets more than 20kPa away from what a normally aspirated car would ever see, the MS forces open loop and reverts to the duty cycle table. The duty cycle table is setup to switch the VICS at 5200RPM per the OEM specification.

Unfortunately, when I logged some pulls I found that this wasn't working. VICS was always deactivated above 5200RPM as desired. But below 5200RPM, VICS only turned on if MAP was above 90kPa.

In this pull, I keep MAP well above 90kPa and get a nice switch at 5200RPM:


In this pull, I generally keep MAP just below 90kPA and the VICS stays deactivated the whole time (except for one small noise blip above 90kPa):


And here's a picture of the kind of havoc that was being created with the VICS output in normal driving:


Looking at the MS firmware, I found code that disables the EBC output whenever you're not in boost. The comment in the code indicated it was meant to keep the EBC solenoid from wearing out. Whatever. Bottom line, on a 1st generation MSPNP, using the EBC function for VICS is not workable without a firmware change.

So I decided to use the "Output 1" function instead of the EBC function. Here's what that looks like:

X4/JS2 is changed to Output1 instead of Boost Control.


Then you setup the parameters for Output1. When you select RPM as the parameter, the numbers you specify are RPM / 100 (i.e., 52 is 5200RPM). You can also specify a hysterisis (I used 1 or 100RPM) to prevent the VICS solenoid from oscillating. Select inverted operation. With these settings, the VICS deactivates at 5200RPM on an RPM increase and activates at 5100RPM on an RPM decrease. Proper operation was confirmed by observing the "Output1" icon on MegaTune/TunerStudio and by physical observation of VICS actuator movement.


YMMV.

TL;DR - MS1 EBC function can't control VICS correctly.
Attached Thumbnails Repurposing MSPNP9495 EBC Output Pin for VICS-wot-run.png   Repurposing MSPNP9495 EBC Output Pin for VICS-part-throttle-run.png   Repurposing MSPNP9495 EBC Output Pin for VICS-havoc.png   Repurposing MSPNP9495 EBC Output Pin for VICS-bc-parameters.png   Repurposing MSPNP9495 EBC Output Pin for VICS-boost-kpa-target-1.png  

Repurposing MSPNP9495 EBC Output Pin for VICS-boost-duty-target.png   Repurposing MSPNP9495 EBC Output Pin for VICS-codebase-outputs.png   Repurposing MSPNP9495 EBC Output Pin for VICS-outputs.png  

Last edited by hornetball; 08-06-2014 at 04:14 PM.
hornetball is offline  
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Full_Tilt_Boogie
Build Threads
67
03-16-2019 08:07 PM
slomiata
MEGAsquirt
5
10-07-2015 01:11 PM
itsMikey
MSPNP
3
09-28-2015 06:40 AM
spidy
MEGAsquirt
7
09-24-2015 03:14 PM


Thread Tools
Search this Thread
Quick Reply: Repurposing MSPNP9495 EBC Output Pin for VICS


Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.