Kitcarlson EMS update, Engine Management System Development Options

[KitCarlson]

A Status Report:

Things are going well on the EMS development.

The hardware has been excellent, no failures, or known limitations.

The DIS with user programmable RPM and MAP advance control has worked great! Sensing means has been trouble free. The dual coils have been replaced by one quad terminal coil (a mechanical change for simplicity). There is a tach output to interface directly to a 914 tach.

The injection strategy was modified to inject a bank every 2 engine revolutions instead of every revolution. This reduced the injector error at short injector times.

Battery voltage compensation for injector open time and dwell are implemented.

Starting fuel feature implemented (Cold start valve not required).

TPS change (derivative) enrichment implemented (An improvement over throttle switch).

Temperature enrichment is implemented. Weather is starting to cool down now for better setup and testing.

A case has been designed by volunteer Mark Bland. He is also a 914 owner. He is also designing the sensor interrupter for manufacture.

Fuel pump, master relay drive, and stall shut-off impemented

Testing on a kitcar with a type3 engine in progress. Runs very well, a great improvement over the carb. Started without hesitation the first try. What a warm feeling!
Why type3 instead of 914?, the kitcar tail is removed with 2 bolts, for easy engine access. Type3 is a baby 914. 914 application comming soon.

An improved bench simulator, and test set has been developed.

A software programmer is developing PC application to dress up the MMI, all setup at the present time with a VT100 terminal emulator running on a Palm® or PC. Setup screens will be posted on my website.

I need a Dyno. Any leads on a reasonably priced ones are welcome. Interested in both engine and chassis types. Even consider a tractor dyno, driven by an axle.

That's all folks!

KitCarlson Please visit http://home.mindspring.com/~dave.c/kitcarlson/

[KitCarlson]

EMS setup:

In answer about Jeff's question about out of the box ready for 914's. I have both 2.0L and 1.7 liter Porsche engines, and 1.6L T1 and T3 VW that will be tuned with the system. These setups could be retrieved from setup library for excellent starting points. Plenty of memory exists for setups.

Setup is very simple at the moment. The VE table is 2D at the moment. I will move to 3D when I get a dyno.

VE closely follows the torque curve of an engine. %'s are entered in table Vs Rpm. A fuel base and fuel scalar #'s are used to bias or grow the table. This enables an engine to be started and roughed in moments. Readings of the total FI pulse in mS and the base and enrichment values are displayed. Also all engine operating parameters are displayed. RPM is updated every 1/3 of a second. All setup values can be changed real time while the engine is running without hesitation. You must at the correct cell for the operating parameter (Rpm, or Temp) for example to feel the change in the engine.

Timing adjustments are similar, two tables (RPM and MAP) and base timing # set with distributor. These curves can be found in service manuals as starting points. Additional tables for temperature and TPS timing controls may be added.

There are also the typical starting fuel table Vs time, Enrichment vs CHT Temperature, and TPS and MAP derivative controls. The enrichment Vs air intake temperature is part of the fuel calculation.

Alpha-N (TPS fuel) is also implemented and can be used in conjunction with the speed density for wild cam applications. I have not played with it much yet.

This is what exists at the moment, things may change as part of the development process.

I have a G-Tech and 5-Gas.

I have been thinking about a brake dyno using an old VW swing axle trans. Locking the differential, and operating the brakes regulated by rpm could give load points long enough for gas tests, with cooling periods. Might be able to measure a crude torque at spring plate (Torsion bar movement). Has this ever been done??