Flex Fuel with MegaSquirt Controller - 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 07-01-2008, 02:01 PM   #1
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Jul 2006
Location: Colorado
Posts: 403
Total Cats: 2
Default Flex Fuel with MegaSquirt Controller

The write up in the MegaManual says
Quote:
MegaSquirt-II (including MicroSquirt) is the first aftermarket EFI controller with direct flex-fuel support for experimental only testing of ethanol fuels and blends.
http://www.megamanual.com/flexfuel.htm

Does this work with MS-1 as well? I am contemplating switching to MS but need to decide between MS-1 and MS-II.

The main driver for me is to run more timing with the improved octane of e-85, but it's not always available ( and not always 85% ethanol either ).

The writeup addresses fueling adjustment, I assume I will have to add a MS Knocksense to back the timing down if the percentage of e-85 in the tank falls to low and I start to get some knock.

Anyway to use map switching to change the spark map if the concentration of e-85 drops below a certain point?

Is anyone using the flex fuel sensor? How is it working for you? What are you doing about timing?

This is not a "Green" or fuel efficiency exercise, it's all about power.

Thanks in advance,
--Chris
Chris Swearingen is offline   Reply With Quote
Old 07-01-2008, 03:04 PM   #2
Elite Member
iTrader: (24)
 
Join Date: Jun 2007
Location: Sherman Oaks, CA
Posts: 4,481
Total Cats: 3
Default

id rather have greener car then have 40whp more. interested!
UrbanSoot is online now   Reply With Quote
Old 07-01-2008, 04:28 PM   #3
Supporting Vendor
 
Matt Cramer's Avatar
 
Join Date: Sep 2006
Posts: 2,266
Total Cats: 51
Default

MS-I does not support flex fuel sensors. MS-II can make both fuel and timing changes in response to a flex fuel sensor with the right mods, but it adds a certain amount of spark advance for every % change.
Matt Cramer is offline   Reply With Quote
Old 07-01-2008, 04:41 PM   #4
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Jul 2006
Location: Colorado
Posts: 403
Total Cats: 2
Default

Quote:
Originally Posted by Matt Cramer View Post
MS-I does not support flex fuel sensors. MS-II can make both fuel and timing changes in response to a flex fuel sensor with the right mods, but it adds a certain amount of spark advance for every % change.
Unfortunately the amount of spark change required is not proportional with the fueling.

Would map switching based on a value coming out of the flex fuel sensor work?
If not, does the KnockSense provide enough protection?
Chris Swearingen is offline   Reply With Quote
Old 07-02-2008, 09:08 AM   #5
Supporting Vendor
 
Matt Cramer's Avatar
 
Join Date: Sep 2006
Posts: 2,266
Total Cats: 51
Default

Unfortunately the software currently doesn't support table switching based on flex fuel input. And I don't recommend on relying on a knock sensor to keep your spark settings in tune.
Matt Cramer is offline   Reply With Quote
Old 07-07-2008, 08:54 AM   #6
Hear me Meow
iTrader: (3)
 
skidude's Avatar
 
Join Date: Apr 2008
Location: Outside Portland Maine
Posts: 1,993
Total Cats: 13
Default

We have successfully used megasquirt to convert a yamaha snowmobile to flex-fuel. I won't pretend I know all the details as my task on the team was a completely different aspect of the project, but I know we used a flex fuel sensor from a GM vehicle and it automatically adjusts something important depending on the percentage of ethanol in the tank.

I think they (the engine control part of the team) had to generate a gasoline table, and an E85 table, and the megasquirt interpolates between the two tables. That is the part I'm a little fuzzy on though.
skidude is offline   Reply With Quote
Old 07-14-2008, 07:58 PM   #7
Senior Member
 
Join Date: Nov 2005
Location: Austin, TX yall
Posts: 849
Total Cats: 0
Default

:subscribed: In for the power as well.

Matt, do you have any more info on this or any other links to successful installs for street vehicles?

Chris
Miatamaniac92 is offline   Reply With Quote
Old 07-15-2008, 09:06 AM   #8
Supporting Vendor
 
Matt Cramer's Avatar
 
Join Date: Sep 2006
Posts: 2,266
Total Cats: 51
Default

There's a few discussions on the msefi.com forum - I don't have any particular links to mention but you'll find some accounts of people there running it.
Matt Cramer is offline   Reply With Quote
Old 07-15-2008, 09:34 AM   #9
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Jul 2006
Location: Colorado
Posts: 403
Total Cats: 2
Default

Quote:
Originally Posted by Matt Cramer View Post
There's a few discussions on the msefi.com forum - I don't have any particular links to mention but you'll find some accounts of people there running it.
My MS-II is hopefully on Joe's workbench right now having an input circuit and whatever else added to accomodate the flex fuel sensor. In reality, I won't get to the flex fuel experimentation stage until after September, but I will keep you guys posted when I start the process. The #51 SM2 SystemStrategies.com/DIYAutoTune.com Mazda Miata just has too many events scheduled to start playing with variable fuel mixtures until after the SCCA Solo National Championships.


(* Hey Matt, did I have the cap on straight in the interview?)
Chris Swearingen is offline   Reply With Quote
Old 07-15-2008, 01:35 PM   #10
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,914
Default

It's on the bench, I'm just having some trouble communicating with it. I know the MS itself is operating as the FP output goes true for about two seconds upon powerup and then goes off (priming pulse), I just can't get my laptop to talk to it. I'm not seeing any activity on the Three LEDs, but I'm guessing that's normal for a baseline-configured MS2.

Currently I'm using the new serial adapter that came with your package, I think tonight I'll try using it to talk to my MS, and/or use my RS-232 adapter to talk to yours.
Joe Perez is offline   Reply With Quote
Old 07-15-2008, 04:30 PM   #11
jwx
Junior Member
 
Join Date: Sep 2007
Location: North of Atlanta
Posts: 78
Total Cats: 0
Default

Make sure it installed the drivers. If you need them, they are on our site.
jwx is offline   Reply With Quote
Old 07-15-2008, 05:18 PM   #12
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,914
Default

I used the tiny little driver CD that came in the package with the serial cable, and the adapter subsequently populated itself into my Device Manager tree. I changed it from COM8 to COM1 (which is unused) and configured the port for 115200, leaving all the other defaults such as 8N1, the buffers, etc.

I may simply test it with a null modem and a terminal program to one of my other known-good machines to validate the operation of the port. I expect that perhaps I'm missing something in the MegaTune config, which I've only just started tinkering with for the MS2.

BTW, Sam- can we sneak an addition into the car name somewhere? I'm thinking of The #51 SM2 SystemStrategies.com/DIYAutoTune.com Mazda Miata presented by UNC Law. I'll try to get you a hat.
Joe Perez is offline   Reply With Quote
Old 07-15-2008, 05:25 PM   #13
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Jul 2006
Location: Colorado
Posts: 403
Total Cats: 2
Default

Quote:
Originally Posted by Joe Perez View Post
<snip>

BTW, Sam- can we sneak an addition into the car name somewhere? I'm thinking of The #51 SM2 SystemStrategies.com/DIYAutoTune.com Mazda Miata presented by UNC Law. I'll try to get you a hat.
Two things?
Who is Sam?
and
To get all that on a hat it will have to be a sombrero. Great idea, even more room for sponsor stickers
Chris Swearingen is offline   Reply With Quote
Old 07-15-2008, 06:36 PM   #14
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,914
Default

Uhm, yeah... Chris... You'd think I could remember your name, given your choice of username and whatnot...

As to custom embroidered sombreros, here you are: http://www.asipinatas.com/Sombreros/index.htm
Joe Perez is offline   Reply With Quote
Old 07-15-2008, 07:10 PM   #15
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Jul 2006
Location: Colorado
Posts: 403
Total Cats: 2
Default

Quote:
Originally Posted by Joe Perez View Post
Uhm, yeah... Chris... You'd think I could remember your name, given your choice of username and whatnot...

As to custom embroidered sombreros, here you are: http://www.asipinatas.com/Sombreros/index.htm
No hard feelings Bob, better get cracking on that Sombrero order. We don't run at nationals until Sept 18th and 19th, but will probably be there from the 12th on. That's roughly 8 weeks from now. They said 4-6 week lead time on the site. :sobrerosmiley:
Chris Swearingen is offline   Reply With Quote
Old 07-15-2008, 08:45 PM   #16
Junior Member
iTrader: (4)
 
Join Date: Jul 2007
Location: Indianapolis, IN
Posts: 113
Total Cats: 0
Default

I was looking into this some time back for the same reasons. Could be a fun project. The FlexFuel sensors were a little pricey but I got the impression that there were used ones to be had (though one model tended to fail?). My main snag was wrapping my head around moving from MS1 to MS2 at the time (getting all of the miata mods converted). I was busy so I gave up - would still love to do it. A lot of e85 to be had in Indiana.

Certainly watching this thread.
sotaku is offline   Reply With Quote
Old 07-16-2008, 12:39 AM   #17
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,914
Default

Success.

Started by validating the serial adapter itself. Used a null modem to connect directly to another PC and was able to have a terminal session between them at both 9600 and 112500.

Next, used the 'scope to verify that serial data was in fact getting all the way to pin 38 of the CPU (the actual 9S12C64) when I tried communicating, but was getting nothing back on pin 39. No activity in MT, wouldn't pass the "test" in the comm setup screen.

Yet all this time I know the CPU is alive, because I see activity on the FP line for ~2 seconds at startup...

Finally gave up and re-flashed the MS with the new MS2-Extra code, and now I can finally communicate with it. Man... Two days down and I haven't touched the hardware yet.

Anyway, Chris, I think we're finally in business. I'm going to try to get the cam input triggers done tomorrow. If I can get to the point where I see an RPM indication, I'll be happy. Gotta figure out how to configure an NA CAS in MS2. The wheel decoder in this software is way different from what I'm used to.
Joe Perez is offline   Reply With Quote
Old 07-17-2008, 12:43 AM   #18
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago (Over two miles from Wrigley Field. Fuck the Cubs. Fuck them in their smarmy goat-hole.)
Posts: 26,317
Total Cats: 1,914
Default

Good news, Chris- your MS2 is officially Squirting and Sparking.

I built the CAS input and ignitor output stages this evening and just got done testing them. The circuit is a bit of a hybrid- for the inputs I built the 4G63 circuits exactly as spec'd in the MS2Extra docs, including the second phototransistor circuit: http://www.msextra.com/ms2extra/MS2-...4g63.htm#2hall

For the spark outputs, I deviated from the MS2E docs and built them to MS1 spec, using Q6 and Q8 with 5v pullups through 100Ω on the collector side, as I'm more familiar with this circuit and I know it works on both the stock igniter and the COPs.

So I've got good activity on both spark outs, and both INJ outs (I haven't modified those, and don't plan to.)

Now it's decision time. I've got to find a place to mount the two big FETs for IAC and WI control. I've already removed and tossed Q16, the high-current ignition driver, as it's worthless in this application. So I need to make one more space on the heatsink. I'll give you the choice here- I can either remove R37 & R38 which will defeat the injector overcurrent protection circuit, or I can remove Q9 & Q12, which will defeat the ability to run Lo-Z injectors. I'm leaning towards pulling the resistors- their job is to prevent you from doing something stupid like putting four Lo-z injectors on one channel and blowing up the FET, removing them won't affect the functionality of the system.
Joe Perez is offline   Reply With Quote
Old 07-17-2008, 10:15 AM   #19
Junior Member
Thread Starter
iTrader: (1)
 
Join Date: Jul 2006
Location: Colorado
Posts: 403
Total Cats: 2
Default

Quote:
Originally Posted by Joe Perez View Post
Good news, Chris- your MS2 is officially Squirting and Sparking.

I built the CAS input and ignitor output stages this evening and just got done testing them. The circuit is a bit of a hybrid- for the inputs I built the 4G63 circuits exactly as spec'd in the MS2Extra docs, including the second phototransistor circuit: http://www.msextra.com/ms2extra/MS2-...4g63.htm#2hall

For the spark outputs, I deviated from the MS2E docs and built them to MS1 spec, using Q6 and Q8 with 5v pullups through 100Ω on the collector side, as I'm more familiar with this circuit and I know it works on both the stock igniter and the COPs.

So I've got good activity on both spark outs, and both INJ outs (I haven't modified those, and don't plan to.)

Now it's decision time. I've got to find a place to mount the two big FETs for IAC and WI control. I've already removed and tossed Q16, the high-current ignition driver, as it's worthless in this application. So I need to make one more space on the heatsink. I'll give you the choice here- I can either remove R37 & R38 which will defeat the injector overcurrent protection circuit, or I can remove Q9 & Q12, which will defeat the ability to run Lo-Z injectors. I'm leaning towards pulling the resistors- their job is to prevent you from doing something stupid like putting four Lo-z injectors on one channel and blowing up the FET, removing them won't affect the functionality of the system.
While preventing me from doing something stupid is generally a good thing, I am quite happy with my 750cc High impedance injectors from RC (SH4-750D).
I think Q9 and Q12 can go.
Chris Swearingen is offline   Reply With Quote
Old 07-17-2008, 10:23 AM   #20
jwx
Junior Member
 
Join Date: Sep 2007
Location: North of Atlanta
Posts: 78
Total Cats: 0
Default

Joe,
You could also mount them to the case, or get an extra heat sink and mount them under the board, or "stack" the extra heat sink on the top level(this is how we do it here).
jwx 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 57 07-19-2017 05:11 PM
My solution for Oiltemp and Oilpressure input into Megasuirt (MS3) Zaphod MEGAsquirt 41 01-24-2016 01:25 PM
Walbro 255lph Fuel Pump $50 lsc224 Miata parts for sale/trade 2 10-01-2015 10:17 AM
Any pnp megasquirt for 2001 Big_gumby WTB 0 09-30-2015 04:34 PM


Tags
e85, megasquirt flex fuel

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 06:01 PM.