Shaping the boost curve AKA EBC solenoid tuning - 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 07-30-2008, 01:02 PM   #1
Senior Member
Thread Starter
iTrader: (5)
 
Join Date: Nov 2007
Location: Troy, MI
Posts: 860
Total Cats: 13
Default Shaping the boost curve AKA EBC solenoid tuning

I want to start playing with EBC since my MS is set up for it.

I did some tests yesterday, all in 4th gear @ WOT. The goal in both cases was to see where I hit boost cut of 155 kpa (~8.5 psi) as a very easy way (in the absence of a passenger) of seeing how soon I can reach the target boost.


Setup #1: Baseline, no changes to set up

Did not hit boost cut. Boost creep to about 1.5 psi over wastegate pressure after ~5000 rpm. Refer blue line in graph below.


Setup #2: Disconnected wastegate actuator with open downpipe

Hit boost cut at 2000 rpm. Meaning I can make the target boost at 2000 rpm with EBC! Great turbo choice, after all!!


Setup #3: Disconnected wastegate actuator w/ baseline full exhaust

Hit boost cut at 3000 rpm. Meaning that even with EBC, I can't make target boost before 3000 rpm. Refer red line in graph below.



Since I want to keep my exhaust for now, I want to go with setup #3.


To that end, I installed an MX6 boost solenoid since I had it lying around:



This is how it works, is this different to the GM valve???:

0% DC:



100% DC:




To test the solenoid, I set all the cells in the duty table to 100%, and saw if it boost cut anywhere. No dice. That means it isnt leaking the boost at all as it is supposed to.

Should I just get an ARO/GM valve? Or is there an easy way to tune the solenoid settings (frequency, differential and proportional values) to make it respond?
The_Pipefather is offline   Reply With Quote
Old 07-30-2008, 02:24 PM   #2
Elite Member
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,240
Total Cats: 290
Default

The most amazing thing is that your full exhaust moved your target a full 1000rpm. Is it stock? I see the 2.25" dp - but that was used in the first non signal test.

Did you verify the physical action of the solenoid right? Did you verify the ports with some air pressure? I just went through all this with link and ended up putting an led w/resistor in the ebc circuit so I could verify an actual signal from the ecu.
m2cupcar is offline   Reply With Quote
Old 07-30-2008, 05:16 PM   #3
Senior Member
Thread Starter
iTrader: (5)
 
Join Date: Nov 2007
Location: Troy, MI
Posts: 860
Total Cats: 13
Default

No its an ebay catback exhaust.

I checked the solenoid as per factory manual. At 0% DC you shouldn't be able to blow through Port 3. At 100%, you should. Is there a better way of testing?
The_Pipefather is offline   Reply With Quote
Old 07-30-2008, 05:22 PM   #4
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,860
Total Cats: 1,788
Default

0% you SHOULD be able to blow through, 100% not at all.
Braineack is offline   Reply With Quote
Old 07-30-2008, 05:48 PM   #5
Elite Member
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,240
Total Cats: 290
Default

Still stunned by the change in spool. That's a real eye-opener.

Hmmm... the DC is getting confusing. Let's talk dc + volts for testing. Make sure it closes when powered.

Then I'd verify the MS ebc signal (This is where the led comes in handy for real time testing.)

I'm not familiar with the MS trigger signal, but what about load. Is it sufficient to manage the +v load on the solenoid? or is it something like a +5v signal?
m2cupcar is offline   Reply With Quote
Old 07-30-2008, 06:11 PM   #6
Elite Member
iTrader: (5)
 
Atlanta93LE's Avatar
 
Join Date: Sep 2006
Location: Marietta, GA
Posts: 2,198
Total Cats: 1
Default

Damn...that exhaust is a real killer, but it sounds real nice and stealth, eh? We have the same one.
Atlanta93LE is offline   Reply With Quote
Old 07-30-2008, 06:43 PM   #7
Senior Member
Thread Starter
iTrader: (5)
 
Join Date: Nov 2007
Location: Troy, MI
Posts: 860
Total Cats: 13
Default

Quote:
Originally Posted by m2cupcar View Post

Hmmm... the DC is getting confusing. Let's talk dc + volts for testing. Make sure it closes when powered.
Quote:
Originally Posted by Braineack View Post
0% you SHOULD be able to blow through, 100% not at all.
that must be for a GM valve. For this one Port 3 must be OPEN at 100% DC therefore you SHOULD be able to blow through it. That's the only way it can increase boost with increasing DC.

Quote:
Originally Posted by m2cupcar View Post

Then I'd verify the MS ebc signal (This is where the led comes in handy for real time testing.)
So check the brightness of the LED?

Quote:
Originally Posted by m2cupcar View Post
I'm not familiar with the MS trigger signal, but what about load. Is it sufficient to manage the +v load on the solenoid? or is it something like a +5v signal?
Its not a signal, I believe it grounds the solenoid proportional to the duty cycle specified in the table. In other words, the solenoid is always "hot" i.e. +12 supplied, but not grounded. Much like every other ECU-controlled device on the car.
The_Pipefather is offline   Reply With Quote
Old 07-30-2008, 08:15 PM   #8
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,860
Total Cats: 1,788
Default

Quote:
Originally Posted by The_Pipefather View Post
So check the brightness of the LED?


its more like the speed it flashes...

IIRC im using a 470ohm resistor, maybe 100ohm...i cant remember.

Braineack is offline   Reply With Quote
Old 07-30-2008, 10:32 PM   #9
Elite Member
iTrader: (5)
 
m2cupcar's Avatar
 
Join Date: Jan 2005
Location: Atlanta
Posts: 7,240
Total Cats: 290
Default

Quote:
Originally Posted by The_Pipefather View Post
...Its not a signal...
yes, I should have just said trigger

Boost solenoids are on/off and work via pulsing- usually going to ground to complete the circuit. When you speak of 100%DC and 0%DC, it sounds as though there's an in between and there's not. It's either +12v or nothing, ON or OFF. The duty cycle (DC) reference is for the percentage of pulses. IOW at 50% DC it is pulsing at rate that for a given unit of time where it is open half the time and shut half the time. I'm stating all this to make sure we're thinking the same.

So- for your solenoid, it wouldn't care what's constant and what's pulsed on the circuit, as long as one goes to ground and the other to hot. I don't see any reason why your solenoid wouldn't work, unless it's broken.
m2cupcar is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 Yesterday 10:04 PM
WTB MP62 (Hotside) (NB2) Rick02R WTB 3 01-03-2016 08:18 PM
Expected intake temps on the track? tazswing Race Prep 20 10-03-2015 12:04 PM
Going back to stock. Need some 1.6 parts. Trent WTB 2 10-01-2015 01:15 PM
Time to start learning and play with tuning The Gleas MEGAsquirt 3 10-01-2015 10:30 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 04:33 AM.