MY SDS EFI Install, Some details of my recent installation of a SDS EFI |
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MY SDS EFI Install, Some details of my recent installation of a SDS EFI |
Joe Owensby |
Jan 30 2009, 10:08 PM
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#1
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JoeO Group: Members Posts: 527 Joined: 7-January 06 From: Spartanburg, SC Member No.: 5,385 Region Association: South East States |
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 |
Jan 30 2009, 11:47 PM
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#2
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JoeO Group: Members Posts: 527 Joined: 7-January 06 From: Spartanburg, SC Member No.: 5,385 Region Association: South East States |
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 Attached image(s) |
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