Hi Gear MPG Gauge

For discussion of Phil Tobin's Tuner Studio software (Only about the tuning software itself, not about how to tune or firmware features)

Moderator: LT401Vette

roarin_mouse
Helpful MS/Extra'er
Posts: 76
Joined: Sat Jun 27, 2009 4:24 am
Location: Umatilla, FL, USA
Contact:

Hi Gear MPG Gauge

Post by roarin_mouse »

Man, I really like Tuner Studio. This has made tuning so easy. I was thinking that an astute software person could create an MPG gauge that works like this: User would enter the RPM at 60 MPH in high gear. That would then be a constant. Now from the injector flow rate, injection duty cycle, injector dead time (opening time), and RPM, the MPG could be determined and hence displayed. This would only be correct for high gear but that's when we want to know the MPG, right. Comments?
1979 Camaro
383 stroker w/Ramjet EFI manifold
MS2 Extra running semi-sequential, wasted spark
LT401Vette
Super MS/Extra'er
Posts: 12697
Joined: Sat Jul 16, 2005 8:07 am
Location: Moorseville, NC
Contact:

Re: Hi Gear MPG Gauge

Post by LT401Vette »

It is on the todo list. I've worked through the formulas in MLV way back.
What it has been waiting for is OutputChannels that are application based, bot controller ini based. I just added the core of that in this week, so this should not be too far off.
Phil Tobin
EFI Analytics, helping to simplify EFI
Next Generation tuning software.
Supporting all MegaSquirt versions and firmwares.
http://www.TunerStudio.com
http://www.efiAnalytics.com/MegaLogViewer/
Support the firmware running your engine:
http://www.msextra.com/doc/donations.html
jsmcortina
Site Admin
Posts: 39587
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK
Contact:

Re: Hi Gear MPG Gauge

Post by jsmcortina »

The formula is fairly easy (although not necessarily wholly accurate). I'll post what I used later.

I plan on building something into MS3 that will improve the accuracy by capturing the injected fuel figure a little better.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
LT401Vette
Super MS/Extra'er
Posts: 12697
Joined: Sat Jul 16, 2005 8:07 am
Location: Moorseville, NC
Contact:

Re: Hi Gear MPG Gauge

Post by LT401Vette »

What part are you improving accuracy on? It always seemed to me the biggest error factor is injector open time, usually just the default 1.0 gets used.
Phil Tobin
EFI Analytics, helping to simplify EFI
Next Generation tuning software.
Supporting all MegaSquirt versions and firmwares.
http://www.TunerStudio.com
http://www.efiAnalytics.com/MegaLogViewer/
Support the firmware running your engine:
http://www.msextra.com/doc/donations.html
jsmcortina
Site Admin
Posts: 39587
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK
Contact:

Re: Hi Gear MPG Gauge

Post by jsmcortina »

LT401Vette wrote:What part are you improving accuracy on? It always seemed to me the biggest error factor is injector open time, usually just the default 1.0 gets used.
The code I've yet to write will sum up the injection pulsewidths before dead time is added. As you say, using 1.0 is "close" but usually not close enough to get accurate mpg.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
roarin_mouse
Helpful MS/Extra'er
Posts: 76
Joined: Sat Jun 27, 2009 4:24 am
Location: Umatilla, FL, USA
Contact:

Re: Hi Gear MPG Gauge

Post by roarin_mouse »

This is good to hear.
1979 Camaro
383 stroker w/Ramjet EFI manifold
MS2 Extra running semi-sequential, wasted spark
LT401Vette
Super MS/Extra'er
Posts: 12697
Joined: Sat Jul 16, 2005 8:07 am
Location: Moorseville, NC
Contact:

Re: Hi Gear MPG Gauge

Post by LT401Vette »

What has been on my todo list for years now, but I think I have all the ground work in place finally to do it. Make a tool to measure injector open time.
The high level plan is to make a wizard sort, where the engine is held at about a 2000 RPM free spin. The ve's for the run range get altered up and down slightly. By taking measurements of the delta PW and delta AFR, a effective one time could be measured. An engineering approach, but could give a much better open time to use in the tune settings and be used for calculating better net pw's.
Phil Tobin
EFI Analytics, helping to simplify EFI
Next Generation tuning software.
Supporting all MegaSquirt versions and firmwares.
http://www.TunerStudio.com
http://www.efiAnalytics.com/MegaLogViewer/
Support the firmware running your engine:
http://www.msextra.com/doc/donations.html
jsmcortina
Site Admin
Posts: 39587
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK
Contact:

Re: Hi Gear MPG Gauge

Post by jsmcortina »

Some other ECUs allow an automatic switch from 1 squirt per cycle (per injector) to 2 squirts and derive the dead time by iterating there. I have that in mind to add to a future MS3 release. (I think that the pulses need to be in close succession to maintain the injector timing.)

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
LT401Vette
Super MS/Extra'er
Posts: 12697
Joined: Sat Jul 16, 2005 8:07 am
Location: Moorseville, NC
Contact:

Re: Hi Gear MPG Gauge

Post by LT401Vette »

That might work better if it doesn't cause to dramatic of and effect. I'll play around with it this week.
Phil Tobin
EFI Analytics, helping to simplify EFI
Next Generation tuning software.
Supporting all MegaSquirt versions and firmwares.
http://www.TunerStudio.com
http://www.efiAnalytics.com/MegaLogViewer/
Support the firmware running your engine:
http://www.msextra.com/doc/donations.html
M30guy
Experienced MS/Extra'er
Posts: 361
Joined: Fri Jul 10, 2009 2:43 pm
Location: West coast USA.

Re: Hi Gear MPG Gauge

Post by M30guy »

jsmcortina wrote:Some other ECUs allow an automatic switch from 1 squirt per cycle (per injector) to 2 squirts and derive the dead time by iterating there. I have that in mind to add to a future MS3 release. (I think that the pulses need to be in close succession to maintain the injector timing.)

James
That's how I figured out the deadtime is by changing the squirts and alt vs sim should give you the same afr if the deadtime is correct. Worked great for me anyways.
Ms2-3.4.2 v3.0 .
Turbo BMW m30b35.
subwoofer
Super MS/Extra'er
Posts: 884
Joined: Sat Apr 30, 2011 12:34 pm
Location: Sandefjord, Norway

Re: Hi Gear MPG Gauge

Post by subwoofer »

DTA recommends toggling 2-stroke mode to determine dead time, so your plan should work just fine. I don't think there is much to be gained by adding code to split one pulse into two at the same point in the engine cycle, but maybe the MS3 should pull the idle up to 2k or so while autotuning to make sure air and fuel are flowing the right way all the time?
Joachim
1974 Jensen-Healey
1990 VW Caravelle Syncro - running MS3+X
2014 Ford Fiesta EcoBoost
jsmcortina
Site Admin
Posts: 39587
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK
Contact:

Re: Hi Gear MPG Gauge

Post by jsmcortina »

I don't think there is much to be gained by adding code to split one pulse into two at the same point in the engine cycle, but maybe the MS3 should pull the idle up to 2k or so while autotuning to make sure air and fuel are flowing the right way all the time?
On my engine at least, the engine runs audibly differently with different injector timing, so it seems very much needed to keep the two injections within a similar time frame in test mode or else you will likely invalidate the test?

The way we schedule sequential injection in MS3, swapping to semi-seq from seq won't work while the engine is running. What I have in mind ought to give a smooth transition from one to the other.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
subwoofer
Super MS/Extra'er
Posts: 884
Joined: Sat Apr 30, 2011 12:34 pm
Location: Sandefjord, Norway

Re: Hi Gear MPG Gauge

Post by subwoofer »

The reason I suggested a raised idle was to get flow velocities up to the point where injection timing doesn't matter too much, but sensitivity will probably be reduced since pulse length will increase somewhat - thus making the dead time less of the total.

Not knowing the code, I suggested what seemed likely to be easier - from a blackbox perspective.
Joachim
1974 Jensen-Healey
1990 VW Caravelle Syncro - running MS3+X
2014 Ford Fiesta EcoBoost
racingmini_mtl
Super MS/Extra'er
Posts: 9128
Joined: Sun May 02, 2004 6:51 am
Location: Quebec, Canada
Contact:

Re: Hi Gear MPG Gauge

Post by racingmini_mtl »

jsmcortina wrote:(I think that the pulses need to be in close succession to maintain the injector timing.)
Make sure you leave enough time between the pulses so that there is no issue either electrical, mechanical or hydraulic from the injectors or the fuel supply. You may need to have a user defined interval because you may have major differences in what different setups can tolerate before you start being in a non-linear region.

Jean
jbperf.com Main site . . . . . . . . . . . . . . . . . . . . . . jbperf.com Forum
Image
jsmcortina
Site Admin
Posts: 39587
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK
Contact:

Re: Hi Gear MPG Gauge

Post by jsmcortina »

Likely at least 2ms between pulses?

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
racingmini_mtl
Super MS/Extra'er
Posts: 9128
Joined: Sun May 02, 2004 6:51 am
Location: Quebec, Canada
Contact:

Re: Hi Gear MPG Gauge

Post by racingmini_mtl »

That's what I would say for petrol injectors but LPG injectors will likely need more than that.

Jean
jbperf.com Main site . . . . . . . . . . . . . . . . . . . . . . jbperf.com Forum
Image
subwoofer
Super MS/Extra'er
Posts: 884
Joined: Sat Apr 30, 2011 12:34 pm
Location: Sandefjord, Norway

Re: Hi Gear MPG Gauge

Post by subwoofer »

jsmcortina wrote:(I think that the pulses need to be in close succession to maintain the injector timing.)
Warping the thread yet again: You do realize that this is getting close to what is needed for CR diesel? Specialist Components/Simtek UK is already selling a diesel ECU based on their latest ECU with an added injector driver box, but it is expensive to say the least. I am not a great fan of diesels, but there seems to be a screaming need for diesel ECUs for engine conversions, people are actually converting the engines to mechanical control instead of going through the hassle of trying to make all the integrated electronics behave after removing them from the donor car.
Joachim
1974 Jensen-Healey
1990 VW Caravelle Syncro - running MS3+X
2014 Ford Fiesta EcoBoost
Shotgun
MS/Extra Newbie
Posts: 26
Joined: Wed Jul 06, 2011 11:23 am

Re: Hi Gear MPG Gauge

Post by Shotgun »

One method of determining the open time is to extend the injector test wizard from MegaTune. Choose an open time and cycle count, and have the user measure the output and input it to a field. Then choose a different open time and cycle count. The equation is (open + opening)*count = measured_volume. You know count and open from both (or all) runs, so it is just a matter of solving the system of equations to determine the one unknown (opening). I did this by hand, and determined that my opening time was 1.1ms.

On a related note, does anyone know what the "fuel flow" units are in MegaLogViewer? The numbers I'm getting don't seem to match anything that makes any sense to me.
Silverback
Helpful MS/Extra'er
Posts: 95
Joined: Mon Jul 21, 2008 9:55 pm

Re: Hi Gear MPG Gauge

Post by Silverback »

I was searching for something related and ran across this... both (the MPG calculation and the injector dead time tester) would be immensely helpful, did anything ever happen with either?
Mark -- aka: WS6 TA, JYDog, 83 Crossfire TA, mpikas, mmp...
MS2 Extra | PCB 3 | HEI Mod | TPI harness Adapter | AEM UEGO wideband | 87 Trans Am | 305TPI | T5 transmission - pretty close to stock
LT401Vette
Super MS/Extra'er
Posts: 12697
Joined: Sat Jul 16, 2005 8:07 am
Location: Moorseville, NC
Contact:

Re: Hi Gear MPG Gauge

Post by LT401Vette »

The MPG gauge (along with power, tq, fuel flow, etc) is in the current stable release of TS.
Phil Tobin
EFI Analytics, helping to simplify EFI
Next Generation tuning software.
Supporting all MegaSquirt versions and firmwares.
http://www.TunerStudio.com
http://www.efiAnalytics.com/MegaLogViewer/
Support the firmware running your engine:
http://www.msextra.com/doc/donations.html
Post Reply