MY SDS EFI Install, Some details of my recent installation of a SDS EFI Options

[Joe Owensby]

I thought I'd share some details of my recent installation of a SDS fuel injection control unit. First, I would like to thank the admins and contributors on this board for all the information available to help me make the choices I made. I spent a lot of time reviewing the posts about various benefits of the different FI systems, carbs, etc. People such as McMark, MarkHenry, Ottox914, and all-- thanks. The info here was very educational. I am posting this to maybe do my part in sharing experience. A qualifier is due up front. I am no expert in cars, engines, etc. etc. , so I would not want anyone to assume that what I post is correct. It is just what I chose to do. Comments or suggestions are also welcome.

Details: My car is a '73 1.7 that I bought new in 73. I restored the car, and started it up about a year ago. Engine is one of Jakes earlier kits. I highly recommend Jake's products by the way. I had a set of Dellorto 40's on the car. I had to learn how to set the jets, etc., and finally had the car running fairly well. I didn't like the cold nature of the carbs with no choke, and I also wanted a car that I could enjoy the radio in while driving. A lot of the noise was from the carbs. I made a sort of air filter type deal to dampen the noise, but I decided to put a FI system on the car using a stock 2.0 manifold system. The FI system on my car was 35 years old, and almost everything on it was shot. This made the decision to go to an aftermarket FI system a little easier. If I had most of the original components, I would have just tried to get new or at least good components. At least now, all the components should be relatively easy to obtain. So, the details that follow entail replacing pretty much all of the FI system components for the car.

After reading about all the available systems out there, I had narrowed it down to a Meagsquirt or the SDS. I chose the SDS because I read a few cases where people screwed up stuff on a Megasquirt and the result was something such as either blowing an engine or letting the magic smoke out of the electronics. I have seen ME screw things up, so I decided to take the more conservative route with the SDS. I am not saying anything against the Mega or Microsquirt systems. However, I can add that the SDS system did turn out to be fairly simple to install and get running- exactly as advertised. I ordered the system on a Friday, and it showed up on my door the following Tuesday, with custom length wires and all. Also, Ross at SDS was extremely helpful in helping me decide what to order, injector sizes, etc. After I got the system, I have asked him two questions about tuning, and the reply was almost instanteous. I couldn't ask for better support than I got from SDS. I'll share details on the system later.


FUEL SYSTEM:
For fuel pump, I bought a new Bosch fuel pump from a local parts supplier. I bought one of the two port filters listed for a 75 914. This was the best price I could find, and was about half of the cost from other suppliers. I wanted as many new components as I could get to hopefully get better reliability.

I bought the front fuel hose/filter kit from AA, as well as their hose kits for the upper and lower engine compartment. These worked well. I had already replaced the fuel lines through the tunnel with SST fuel lines from Chris at Tangerine racing. Great products also. I mounted the pump below the fuel tank, using a removable cover fuel pump mount from a 75 (purchased from a member here). My system had the original type fuel filter before the pump, and I added a metal fuel filter in the engine compartment, mounted where the old MPS was.

I used the original 914 steel fuel rails for the injectors, along with a new stock fuel pressure regulator from AA. This came in set to 30PSI, which was the pressure I had intended to use. I purchased an airbox manifold and throttle valve from another member here, Adidas. He only lives about an hour away, so I was able to pick up those parts personally.

More details next post.

[Joe Owensby]

FUEL INJECTORS:
There is a lot of discussion on this board and others such as thesamba, etc. about what injectors to use. I looked at a lot of options. Several people have used new type Ljet injectors that need slight modifications to fit the original air manifold tubes. These can be found reasonably cheap, but require making a fuel rail or modifying the injectors to accept hoses, and also modifying the injectors to fit the air manifold. Not too big a deal, but something that has to be done. I had almost decided to do this, when I fould new Bosch 0282150007 injectors that were originaly for a VW 411 or 412. These have a flow of 340cc at 3Bar, or about 268cc at 31PSI. This is about 26 pounds/hr at 31PSI, which is a pretty good value to use. These were about $56 each new from Summit. They fit the original manifolds exactly. I wanted to have new injectors as opposed to rebuilt ones, particularly since the ones I had were 36 years old. These are low impedance injectors, so I had to get the resistors installed on the SDS controller. On my engine at high load and high RPM, the injectors max out around a 50% duty cycle, so they are probably a pretty good choice. The recommended maximum duty cycle is 85%, so I am pretty good here.

SDS sytem includes wiring as specified. I ordered a system for the Djet injectors, and they sent the system with the resistors pre-wired along with wires to the installed connectors for the Djet. They don't have boots for the injectors, so I ordered boots from AA, and installed these on the SDS wires, along with a heat shrink tubing cover. In the first photo below, you can see the resistor block and the manifold pressure sensor both mounted on the firewall in the engine compartment behind the driver. This seemed like a good place to put them. I tried to route the wires as best as I could to keep them away from spark plug wires. There is also a relay mounted on the side engine compartment where a "6" oil cooler would go. This is for the aux air inlet valve for fast idle when engine is cold. You can also see two "new" red wires coming out of the rear end of the relay board. This is where I picked up the power for the SDS controller and the injectors. I tapped into the relay switched power supply that originally went to the original FI system. This tap is unfused, so i added an external fuse to the controller and the injectors, as can be seen better in the second photo.

More to come.

[Joe Owensby]

FAST IDLE VALVE: I ordered the system with the fast idle valve. This is progammable to open to speed up the idle when the engine is cold. I have this set to close about 217 head temperature. I also plan to add a second input from my air conditioner compressor to actuate the valve when the AC is on. I routed the hose from the outlet ont he original port in the air box that went to the original fast idle valve. First photo shows the valve mounted on the side wall near the relay box.

AIR TEMP SENSOR: I mounted the air temp sensor (comes with controller system) on the back wall of the engine compartment. This ends up being fairly close to the actual inlet of the horn on the air filter inlet. I originally had the sensor mounted in the hole where the original temp sensor for the fast idle valve was located. This location read about 30 to 40 degrees hotter than the outside air, so now the sensor is on the back wall. Shown in second photo.

ENGINE TEMP SENSOR: The system came with a standard (I think Bosch) temp sensor. It just screws into the threaded port on the head near the #3 plug. This reads surprisingly close to the temp sensor I have under the #3 plug.

THROTLE POSITION SENSOR: The throtle position sensor supplied with the SDS system had a hole that mates with the original throttle valve. I made an adapter plate from a piece of 1/2 inch aluminum. Just bored a clearance hole for the shaft on the throttle valve, tapped two holes to mount the new TPS, and finally drilled holes to mount the assembly to the throttle valve. Took about 1 hour total.

[Joe Owensby]

CONTROLLER MOUNTING AND WIRING:
I considered a lot of places for mounting the controller. Hearing that water damage was the most common cause of failure, I decided to mount the controller inside the car, on the back firewall between the seats. I routed the wires to all the components to the driver's side of the car, up along the front engine shelf, and then through a 1 1/4 inch hole in the firewall. I used a rubber grommet to fit the 1 1/3 hole. I also added a piece of aluminum with a smaller grommet that I glued on the outside of the firewall insulation. I glued this on the top half, and left the bottom half open to allow drainage. The wires were routed through the firewall, and into the SDS controller. If I had it to do over, I would have had the thrugh hole located higher so it wouldn't have been behind the controller. The first photo shows the wires from the engine compartment. Second one shows wires going to the mounted controller.

The third photo shows a modification I made to the backpad to allow it to go over the controller. I just cut out a portion of the paperboard on the backpad in the area where the controller would be. I then cut out the foam in this area, and replaced it with a 1/4 inch thick piece of foam followed by a thin 1/8 or so piece of fiberboard. I then fiberglassed this to the back of the backpad, as can be seen in the photo. This created a compartment for the SDS controller, and allows air to circulate around the controller for cooling. Worked out pretty good.

I have a PLX O2 sensor mounted on the exhaust. Wires from this were run up along the underside of the motor alongside the speedometer cable. I drilled a hold in the lower firewall near where the fuel lines go into the tunnel, and routed the O2 sensor wires into the tunnel up to the console area. I have the actual controller for the O2 sensor mounted inside the center console where it drives the gauge, and there is a wire that goes back to the SDS controller to provide O2 feedback.

As ordered wire lengths for these component locations were:
Injectors from Resistor block; 26, 29, 75, and 79 inches.
Controller to resistor block 48
Controller to following. tach signal- 102, TPS 92, Fast idle 105, MAP 48, CHT 118, ait temp 92.

[Joe Owensby]

START UP AND TUNING:
I forgot to mention at the baginning that I have a fuel only system. This is much simpler than the systems that control both fuel and spark. The SDS fuel only system operates primarily by engine RPM, Manifold pressure and changes in throttle position. These values are modified by other inputs such as engine temperature, start up conditions, and air temperature. The engine temperature input has corrections for adding extra fuel as need for the engine to run well when cold, and also to control the setting for fast idle when the engine is cold. For specific details, refer to sdsefi.com, where you can get a complete copy of their manual. Programming is done using a supplied LCD unit with pushbuttons. I made a mount to fix this to the ash tray for use during tuning. I had seen this by someone on this board, I think McMark (EDIT by McMARK: It was Mark Henry). It makes it pretty handy to do the tuning. There is also a mixture knob that enables you to adjust the mixture during tuning. The SDS unit has an O2 logging feature that is pretty neat. For tuning, you just clear the logged values, and then do a run in 3rd or fourth gear from a low RPM to a high RPM. The unit records the O2 levels for each increment of 250RPM. You then just adjust the mixture percentage to get the O2 levels you want. Photo below shows the programmer, and you can also see the gauges I added to the console. I have a digital cyl head temp gauge as well as the O2 air/fuel ratio gauge installed in addition to the std. volt and oil temp gauge. Console still needs some spiffying up.

After installing my system, I first checked out the fuel system for correct pressure, etc. I then tried to start the car; and believe it or not- it started up after only about 4 seconds of starter operation. This was with the program settings as supplied by SDS. WOW, was I amazed!!!! No magic smoke let out of anything, and I had a running engine. The original settings were just an estimated value they put in based on the specifics I gave them for the engine and injector sizes. Can you say "SIMPLE DIGITAL SYSTEMS"?? I was able to immediately drive the car down the road and make some basic adjustments using the mixture know to get a feel for what ranges of settings I needed for good mixture conrol. I did the basic tuning myself by making trial runs on a country road. Just make a full or 3/4 throttle run and then coast off onto a side road, and then review the o2 readings and make adjustments as needed.

I now have the car tuned in pretty well for all conditions except idle. The engine I have doesn't have a lot of vacuum at idle RPM, so there is sometimes some variation in the idle. I am getting this smoothed out fairly well with the combination of RPM and manifold pressure settings. I also ended up drilling out the hole in the throttle plate a little to allow the engine to idle better as the low vacuum levels didn't pull enough idle air throught the standard hole. I had to open the idle bypass screw quite a lot, and it ended up whistling. A slightly larger hole in the throttle plate fixed that problem, as I could turn the idle bypass screw back in to a reasonable level. I have also experimented with the option for just having an idle injection rate setting that can be set on the SDS systems for cars with cams that do not provide a high vacuum when idling. This works OK, so I may end up using this option. I expect to do a little more tuning tomorrow, and then remove the programming unit from the ashtray.

By the way, I made the first road trip, about 200 miles each way, on the car last week.The unit worked great. It has the option where you can turn on the closed loop control to keep the A/F ration about 14.7. This worked great when driving down the interstate at about 75 to 80 mph.

If anyone has any comments, questions, or suggestions for improvement, please let me know. JoeO

[Todd Enlund]

Great post Joe!

This is the kind of info that makes this site so great. Guys sharing what they learned so that others can benefit.

I'm gonna start with IDFs, but I'll switch to FI when I can afford it.

If it's not too much to ask, what do you figure you have into the FI system? Carbs can be had pretty cheap (IMG:style_emoticons/default/biggrin.gif)

[McMark]

GREAT WRITEUP Joe! Thanks for taking the time to share your experience.

[Mark Henry]

(IMG:style_emoticons/default/smilie_pokal.gif) Very good write up!

Watch your head temps running closed loop, if they are getting too high I'd switch back to open. On the 1.8 I took the controller/WB off for 2 seasons and never looked at my values (wife hates the gear/wires) once I did put the controller/WB back on everything was still bang on.

I ordered the system on a Friday, and it showed up on my door the following Tuesday, with custom length wires and all. Also, Ross at SDS was extremely helpful in helping me decide what to order, injector sizes, etc. After I got the system, I have asked him two questions about tuning, and the reply was almost instanteous. I couldn't ask for better support than I got from SDS. I'll share details on the system later.

This is normal every day service from SDS. Absolutely no BS ever.
So how long did your install take? Actual time working on your teen.

BTW....wrong Mark on the ashtray mount....that would be me. (IMG:style_emoticons/default/biggrin.gif)

[stepuptotheMike]

Joe, looks great!! Thanks for taking the time to write up.

How are the sounds levels on your car now?

Mike

[championgt1]

Very good writeup!

Classic thread? (IMG:style_emoticons/default/smile.gif)

[brp986s]

Is emissions testing required in your locale for this car? Howabout fuel economy?

[Mark Henry]

Is emissions testing required in your locale for this car? Howabout fuel economy?

If emissions is an issue then you're best off to stick with stock FI. No AM (After Market) system claims to have less emissions than stock, even though you could probably program it to pass easy. No AM system would pass visual unless you did an amazing job hiding things.

I know a guy who swaps out a stock engine every 2 years for his test. PITA

When I keep my foot out of it (hard to do) my mileage is as good or better than stock.

[jc914]

Very Nice post congrats

[stepuptotheMike]

Is emissions testing required in your locale for this car? Howabout fuel economy?

Beauty of South Carolina.... no inspections, no nothing. Just pay your taxes and drive.

Mike

[ottox914]

Looks good! I would continue to work with the settings for your idle, rather than use the TPS idle programing. My ITB's provide a less stable vac. signal that the OEM plenum system, and we were able to program in a smooth, steady idle with some patience.

Good Work!

I was amazed at the mpg even with the ITB's, larger injectors, and a heavy foot. Of course, now with a turbo and at an auto cross, the mileage takes a dive, but around town and on the highway, I have hit 35mpg at 70 mph, with restrained town driving.

[Jake Raby]

Very comprehensive write up...
Now you see why I use and recommend SDS over pretty much anything else.. The tech support is unparalleled and they won't treat you like an idiot if you have a question...

How is the system behaving at low RPM with that engine combo???

BTW- I set my fast idle to deactivate at 187F, when it was set higher I had issues with fuel intrusion into the oil.

I see you have V 16, I am doing some beta testing of version 16.6 with a self learning AFR target chip in use.. If it continues to work as well as it has been, this will give SDS another big boost, then we'l share details...

My 148,000 mile 912E is now getting over 40 MPG again with this chip enhancement, prior to the chip the best MPG I could attain was 34-36.....

This post has been edited by Jake Raby: Jan 31 2009, 09:01 PM

[smdubovsky]

Nice work. I had an SDS on my old Jeep. However you should relocate the air temp sensor back into the intake tract. Its needs to measure the exact air temp entering the motor not ambient.

[Mark Henry]

Nice work. I had an SDS on my old Jeep. However you should relocate the air temp sensor back into the intake tract. Its needs to measure the exact air temp entering the motor not ambient.

(IMG:style_emoticons/default/agree.gif) Don't know how I missed that...yes it should on the intake somewhere before the TB.

[914werke]

Is emissions testing required in your locale for this car? Howabout fuel economy?

If emissions is an issue then you're best off to stick with stock FI. No AM system would pass visual unless you did an amazing job hiding things.

I know a guy who swaps out a stock engine every 2 years for his test. PITA

Not to be arguementive or to Hijack but how many monkys performing these tests are going to be old enough to visually determine if the installed system is OE or not.
Has any one ever seen the referance photos they use ? Do they evan have referances for 35yr old cars?

[jd74914]

I have always wondered that too. There is no way that the guys who do emissions tests around here know what stock is on relatively unseen cars. And on top of that, if you claimed that the new additions were replacement parts, I don't see how anyone would really have grounds to argue.

Hyjack over. (IMG:style_emoticons/default/laugh.gif)


Very nice install and writeup Joe. Thank you. (IMG:style_emoticons/default/smile.gif)