DIYEFI.org Forum

Tell us what you require to run your engine in a minimal way.

Obviously you will need something to read your existing wheel pattern, but what else?


Right now we have :

Solid communications
Solid pure speed density
Up to 6 fuel outputs configurable however the author of the decode wants to use them
Fixed/static injector dead time
Live tunable single VE table
Save state of tune via screenshot and flash dump
All fixed config and lambda table adjustable via recompile of firmware (injector size, displacement,etc)
Real time data display in the tuner
Ability to reset the device remotely
Ability to overide sensor values in various ways


We don't have :

Any correction algorithms such as engine temperature enrichment, transient corrections, altitude correction, etc
Any form of pre start priming pulse
Any form of post start enrichment
Any form of fuel pump control
Any auxiliary item control
Any idle control algorithms or logic or outputs
Any number of other things that I can't think of right now
Any variable averaging


I was using the stock ECU to :

Warm up the engine
Provide fuel pump control
Provide idle air and idle up control
All ignition duties
Any other aux item


I found that :

I didn't need any transient enrichment
I didn't need any priming pulse
I didn't need any after start enrichment
I didn't need any averaging
Bad tune state fought the idle air control of the OEM ECU


Stuff that I wanted :

Warm up enrichment of some sort
Tunable lambda table contents
Tunable table axis values
Syncing of visible values with ecu contents
More cell tuning options (areas, by % etc)
Some sort of IAT correction curve/algorithm or preferably move the sensor to where it didn't heatsoak


Tell us what you want/need before you alpha/beta test FreeEMS on your engine, and point out anything else we have or are missing, etc.

Fred.

Things I need before I can use it are a rev limiter.

Things that would be nice include.
-- soft rev limit. (I need full throttle to run at 3k RPM, soft rev limit will help prevent oscillation perhaps another solution would be nice)
-- prime pulse
-- intake air temp compensation

My application is generally fixed 3k RPM or idle at say 1k RPM. Idle isn't required. 1cyl, fuel only, ambient temp ranging from -20C to 5C (-10f to 40f), hall pickup off a magneto magnet.

I think the only physical part I'm missing is the TA card, or equivalent brain board. If I had a brain board, I would likely have the rest of it together in a week or perhaps two.

Good call on the RPM limiters - they would need hysteresis too. Thanks. Not too difficult to implement either.

jharvey wrote:-- intake air temp compensation

What do you mean? Just the standard "hot air is less dense" stuff? If so, built in provided you can provide an accurate reading. On the Volvo the reading was a lie, so I couldn't use it - I opted for fixed 20C instead which worked by and large. If you don't mean that, please explain :-)

Fred.

For beta testing on my car:

1986 Porsche 944 Turbo with 2.7 liter big bore engine with Wossner pistons and Carillo rods, bigger turbo, completely new wiring loom which will be setup to easily swap standalones in and out, sensors out the ying yang, etc. The wiring loom will be configured for sequential everything, lots of sensors, etc but will terminate inside the car in a cheap AMP Circular Plastic Connector. My Link G4 Xtreme will have a short adapter harness going to that CPC. Thus I can use almost any standalone on my car by making a short adapter harness going from standalone to this CPC connector, adjusting things in between like two injectors into one output for batch, or two coils into one for sequential.

Sequential Injection - My smallest reliable injectors are a set of 75lbs low impedance, I also own a set of 120lbs low impedance, I have stock injectors (also low impedance...) but no longer trust them due to one already seizing open on me.... Combine with no enrichments, and it might get tricky but I could probably live with batch for beta testing (see above).

Wasted Spark - I have four coilpacks, which will be wired for coil per plug, but could be done as wasted spark (see above). They are LS2 coils, so just need logic level control.

Wideband Input - Doesnt need to be control/closed loop/etc just to view and hopefully log. I dont have a display for mine (PLX Wideband).

Crank Signal - I am undecided... Stock is 132+1 and I will likely be using that with my shiny new Link G4 Xtreme, with a cam trigger for sequential. But I have all the parts for a 36-1 and a 60-2 crank trigger in conjunction with the stock 132+1. So Any of the above would be needed.

Fuel Pump Control - Optional, I would just need on/off control, basically an Aux output would work. Do you mean that kind of control, or that lame ass PWM returnless control? I can wire it to turn on another way though, so this is optional.

Tach Output - Would be nice... But optional for beta testing/minor driving around.