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 The dual coils have been replaced by one quad terminal coil (a mechanical change for simplicity).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/

Very cool! Can't wait to see the dyno results including the air/fuel ratio across the entire rpm range.

Got an estimated cost on it?

Why I ask is because I did the SDS group buy thingy last winter/spring and one thing I learned is that some VW and Porsche people are just a tad thrifty. Lots of tire kickers, few buyers.

I'm not trying to discourage you, but this is the reason almost all of your competitors build systems generic to any make of engine.

I can buy a Dual 44 IDF Weber Kit for about $600 so I would be willing to pay about $1200 for a well thought out f/i system designed specifically for the 914.

The system will be affordable. I like to get the most from my money also. The design supports this idea.

There is no reason the EMS cannot be used on other engines. My plans include applications to other engines as time permits. This involves mainly wiring harness work. I will have other options for sensor inputs. The ECU will remain the same. Software will be expanded.

My best guess at the moment is a selling price under $1200 for a complete turnkey D-jet upgrade. This price would include EMS unit, wire harness , TPS, quad coil, ignition wires and setup timing sensor. A inexpensive VW distributor may be used as the core.

Kitcarlson

I love this nuts and bolts, err, transistors and resistors stuff.

I am interested in replacing my D-jet, yes.

Been keeping an eye out, it's looking very nice, hurry.

Post 906, it's getting serious.



M

Since other units out there run about $1200-$1500 I would be interested in a system that was under $1000. And it would replace those damn Dellorto carbs on my Squareback!!!!!!! I hate carbs...gimme FI any day!!

One thing to consider about any aftermarket FI...

Daves EMS is more than just a D-Jet replacement, it also has ignition control.

Dave, do you intend this to be plug N play, meaning bolt it on out of the box, and the 914-specific programming is either provided in hard copy or already loaded?

Aftermarket systems are generic and must be tuned...a major hassle and expense.

Dave,

This sounds super. I'm currently putting together the MegaSquirt controller as my first attempt to "upgrade" the stock FI. Its been a learning process. By the time I'm finished you should have some good data for the 914. I'd like to be able to compare them.

Keep up the good work.

Has anyone thought about developing a new intake system for larger displacement engines.

The argument always comes up when drying to adapt the DJET system to larger engines like 2270ccs and larger, that the limiting factors for air flow are the inner diameter of the intake runners or the throttle body. People talk about enlarging throttle bodies, but not seeing any real benefit because the runners are too restrictive.

One approach is to use individual throttle bodies on a Weber-like manifold such as they do with the CB Performance EFI kit, but then you are faced with making sure all your throttle butterfiles are synched and either individually read or their position read off a common linkage.

Couldn't you adapt a larger diameter throttle body from another Bosch equipped car (i.e. Volvo, Rabbit, etc.), and then have larger diameter intake runners and a the plenym box fabbed to mate to the cylinder heads? Then you could adapt larger injectors (that can pump more fuel) and maybe a more aggressive fuel injection compatible cam?

Just thinking...

(accessory to thread-jacking)

How about billet heads, made to do something a little more?



M

I don't see the intake runners or the plenum as being too restrictive with bigger motors and the stock FI, it's more of a combination of the MPS and ECU not being able to be easily tweaked to compensate for the increased demand for more fuel/air. That and most people when going to a bigger engine, use a more aggressive cam, again, the MPS and ECU are not designed for this change.



It all comes down to fine tuning, the $100.00 MS can perform just as good as a poorly setup $10k Motec system.

My MS ran crappy until I spent time with it on the dyno....

I agree with Jeff, plug-n-play would be best for most people, as long as they have the ability to tweak the system if they need or want to.

I'm not aware of any aftermarket f/i systems designed specifically for a 914. The Redline Weber system looks very interesting and could probably be adapted to work. Here's some more info on it.

The redline stuff looks pretty good. I like these bodies.
throttle bodies

this is the direction I want my teener to take.

I think this setup is in the $2500 range (not installed and no dyno time included in that price)...ouch......

Tune it from the passenger seat using a lap top and a g-tech pro. I know, it's not the same.

anyone use cb performance's Digital fuel injection? what about a modified djet w/ dual throttle bodies?

Thanks for that link.


M

CB's system, all I've heard is that it blows chunks and D-jet will only tolerate minor changes to the cam and intake, dual TB's would just totally F___ it up.

If you use multiple TB's, where do you get the vacuum signal, and how do you interpret it?

I would love to have multiple TB's also. But without combining the intakes into one plenum I suspect that it's hard to measure airflow or manifold pressure in a straightforward way.

Porsche did it with MFI by NOT measuring anything except throttle position and RPM. This is an open loop system and very different from the programmable aftermarket systems I have seen.

Humm, I've heard that the CB system is pretty good.

To me, a FI system MUST be tunable to whatever it mounts to. If you have an after-market system on a stock engine then later transplant it on another like engine that's been beefed up there should be no problems except for the necessary mapping/tuning i.e. no new parts necessary or else a very limited number of parts changed (injectors, intakes: YES; brains, TPS, etc.: NO).

Using off-the-shelf parts is great! Systems I've seen that are specific to a particular car actually cost more so I don't see that as an advantage.

Compared to?? Stock FI, single carb, dual carbs???

The CB system works, it's just that now there are better and cheaper options that work better (or at least have more options or inputs/outputs)

The Megasquirt (and almost all other good PEFI systems) allow one to set it up similar to the factory MFI, basicly TPS and RPM based = Alpha-N, a total pain to setup if you don't know how to tune it, and it does not compensate for changes all that well, if at all

For systems setup to use a MAP sensor, multiple T/Bs are handled by running a line from all of the T/B's to a common port. Some experimenting must go on to optimize hose length and size.

I wonder if you could run 4 lines to 4 separate MAP sensors?

I think it could be made to work if there was custom code involved.

Oh god, yeah, you could, if you wanted to waste...er, spend...that much money on parts and programming.

My SDS system runs on both the TPS and MPS, or just the TPS, or just the MPS.

You only need one MPS.

A_C_Nut, go and ask about the CB system over on the STF fuel injection Forum. You won't find very many fans.

Kitcarlson has the right idea, a bolt on system would be great.

Below is the link to my SDS install, the big problem with my system is fabracating the crank trigger mounts and disc, welding in a bung for the O2 sensor, coil mount etc. etc... total PITA. The rest was not that bad.

http://www.914world.com/bbs2/index.php?act...f=2&t=5396&st=0

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??