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I'm getting close to starting the installation of Simple Digital Systems (SDS) EM-4D, so I thought I'd start a topic on the build.

First, the specs:

* 412 Coupe 4 speed daily driver
* 2056 cc Type 4
* 9550 RAT cam
* LE-180 heads (914 2L combustion chamber, 42mm intake, 36mm exhaust)
* Mallory Unilite vacuum advance distributor, Mallory Promaster coil, Mallory Hyfire CDI
* Stock 412 heater boxes & Thunderbird exhaust (until Tangarine Bus Header is available from RAT)
* 2L Bus plenum and throttle body
* 2L 914 runners
* Ford "Design II" F1TE-D9A (Bosch 0280150947) 24# injectors (modified)

Ross at SDS was very helpful in answering my pre-sales questions and the system with custom wire harness was delivered in a few days. The ECU will be housed in a gutted D-Jet ECU box located in the stock location for the 412 Coupe (left rear quarter panel). The box is fluid tight and should not be a problem. I made a custom DB9 cable to extend the SDS Programmer into the cabin (right connector).


A harness was made to include SDS, new gauges, and CDI under rear seat. A second engine bay disconnect will be added for TPS and ET for easier engine removal. The MAP sensor will be placed on the firewall and the AT sensor will be placed in the stock air cleaner.


I plan on installing the SDS on the stock engine so I can learn how to tune on a "disposable" engine (I got it for $25) while I assemble the 2056.

Helpful tips and comments welcome,
Bill

P.S. edits in bold

Looking good. Can't wait for for more pics. Mind sharing the pice of the harness?

SDS charges $42 for custom harness length. Each wire length can be specified. Otherwise, standard length harness is included with ECU. The custom length is very much worth it. Here's what I did:

Main Harness:
* TPS (to throttle body) - 67"
* MAP (to firewall) - 67"
* AT (to air filter) - 87"
* CHT (to cyl#3) - 45"
* Mixture knob (to dash connector for mixture knob) - 240"
* Tach (green wire to multi-spark box tach output under rear seat)- 96"
* WBO2 (grey wire to LM-1 output) - 240"
* ECU Power (red wire to ignition power, 1-5Amp fused) - 36"
* ECU Ground (black 20 Ga wire to chassis close to ECU) - 36"

Drive Harness:
* Injector Ground (black 18 Ga wire to chassis ground close to ECU) - 36"
* Fuel pump relay (orange wire to optional relay) - 36"
* Check engine light (pink wire to fasten seatbelt dash light) - 240"
* Injectors (wire bundle to injector harness, extends from ECU to disconnect in engine compartment) - 26"

Injector Harness:
* Cyl#1 - 45"
* Cyl#2 - 48"
* Cyl#3 - 12"
* Cyl#4 - 9"

I spent more for PVC heatshink, wiring for gauges/coil, connectors, grommet, and fuses to build out the rest of the harness to handle the gauges and CDI/coil.

Once I install the harness through the firewall and adjust the sub-harness lengths, I'll shrink the jacket on the main harness before installing the grommet. Additional sections of heatshrink will be added in the cabin between the rear seat where the CDI branch will take off and the dash where the gauges and SDS controls will reside.

I'll post more as the install progresses.

Very cool, where will the Ecu live? Package tray, under seat?

The ECU will go in the stock location for a 412 Coupe - the engine bay left quarter panel. It's held to the black plate in the picture. The harness routes through a grommet in the pass-through under the heater relay (see gray OEM harness in picture behind relay with red lever).

Niely done! Ray

Very stealth!
Won't you use the D-jet injectors I send you?

Could you take a pic of the bus plenum coupled to the 914 intake manifolds?

Wally wrote:Very stealth!
Won't you use the D-jet injectors I send you?

Could you take a pic of the bus plenum coupled to the 914 intake manifolds?

I'm going to start with the L-Jet injectors and see how it goes. I like the connectors better than the D-Jet ones and the L-Jet injectors should be able to keep up with a 115 hp 2L. Do you want them back?

The 914 2L runners mate up to the 2L bus plenum nicely (excuse the pre-sandblast condition).

This is going to be nice! Ray

Good picture! tnx!

No, transport costs are a bit prohibitive for that.

Oops, I don't know where I got the idea that L-Jet injectors were high resistance... I mistakenly ordered the SDS harness without resistor pack. The L-jet injectors I have are low resistance ~ 3 ohm (and 2 out of 4 are stuck). I could add the resistor pack and get the L-jet injectors cleaned, but I'm going to try Ford F0TE-D5B (Bosch 0280150556) injectors. These are 4 hole discharge injectors with disc activation. Appearantly, the 4 hole discharge provides improved atomization, but they may be more suseptable to clogging. They are rated at 43.5 psi with 30.8 hp/injector at 80% duty cycle with .52 BSFC (see data). I got a rebuilt set of 4 from Precision Auto Injectors via ebay for $100 delivered. Here's a picture from www.precisionautoinjectors.com




The injectors and runners will need some modifications, so I'll test them out on the 1.7L before going to the new 2.0L.

I've also decided to go with a vacuum advance Mallory Unilite from Aircooled.net. I've read the vacuum advance is preferred for drivability and gas mileage in a daily driver.

Any advice? Thanks, Bill

Bill K. wrote: They are rated at 43.5 psi with 30.8 hp/injector at 80% duty cycle ...
Any advice? Thanks, Bill

4x30 = 120 hp maximum. I think they are too small.
Remember that injectors are rated for modern engines that run at 14,5 AFR.
Our aircooeld units run at much fatter mixtures like it or not. So you may need to deduct some of that hp and I suspect (hope for you) it makes more then 110 hp..

Thanks Walter. I didn't take into account AFR. Perhaps the 24# Blue Top version (0 280 151 947, or F1TE-D9A) rated at 37.3 HP/ at 39 psi with 80% duty and .52 BSFC is more appropriate for engine rated at 115+ HP. If I understand you correctly, these would keep up with 133 HP motor (37.3*4*13/14.5 = 133).

Or, the Red Top 30# (0 280 150 945 or F1SE-E5A) rated at 43.9 HP/ at 39 psi with 80% duty and .52 BSFC for up to 43.9*4*13/14.5 = 157 HP.

For referance Porsche 2.0L injectors run 37# (380 ccm/m) at 29 psi.

The 24# Blue Tops seem to be a better pick. Agree?

Yes, like the red tops, surely, because would you want to keep your injector flow rating to be so close to your predicted exact hp output?

I would and have used injectors that also have much more spare room for hp increase. That is also the nice thing about programmable injection imo: you can use a generously larger injector then you think is needed and just adjust the opening time. But don't overdo it of course to keep idle injection times not too short.

My 2056cc for instance used vw golf/rabbit high impedance G60 injectors that normally feed the stock 1,8 160 hp compressor engine of the VW Golf G60. Those are rated at 280cc/min IIRC but in a n/a engine are probably good for 180 hp. They are also 4-nozzle; never gave me a problem with clogging (just use a good filter).

I think you can choose a 230-280cc/min or about the same in 'lbs' injectors safely. Not sure what hp rating the G60's give each (40-45hp-ish?), but you get my line of thinking I hope
This way, you have a bit broader array of injectors to choose from and can try to get the best deal

Here is the real question. Was the lbs /hr and potential horsepower rating of that set of injectors...derived at using the maximum pressure of 43.5 psi and 80% cycle rate ..or at some lower presure setting?

IF that is in fact the pressure used to derive the HP and flow rating...they may indeed be slightly small for maximum enrichment....AND they may be too small in some of teh middle ranges to. There is going to be a lot of time through various parts of the rpm band that you are nowhere near the maximum pressure...but still need healthy feeding. Ray