Mega Squirt EFI controller
Custom buil computer system
LCD Screen for computer system
Autometer 3401-M Boost/Vacuum gauge
Custom built fuel rail
944 944 Turbo injectors
Well here goes the begining of the long story about the EFI project. Lets start by getting one thing straight, I hate CIS. Even though it does work well when it works (keyword WHEN), I just hate the idea. I knew from the day that I decided to make this car fast that the CIS just wasn't going to cut it. The airflow meter plate adds too much restriction, and it pegs itself after 2bar of boost, which would be too limiting. So I knew I needed EFI. First choice Electromotive. We use Electromotive ignition on our race cars (carbueted by class rules), and we are a dealer for all of thier products, but the stuff is pretty expensive even with my rather large discount. Then one day Larry comes to the shop and shows me this crazy MegaSquirt thing, an EFI computer for $110. I was skeptical at first, but after downloading the tuning software (written by a fellow FAST 5000TQ owner, Eric Fahlgren) I knew that was the one for me. Larry ordered 2 kits even before I owned my Q car, one kit for my Porsche 914, and one for his 914. Then of course the path of mine changed when I purchased the Audi. So mid February 2003 we assemble the first kit, but I wasnt anywhere near ready for EFI as I had just barely made the ignition system work properly again after a month long nightmare. About mid March I got my second parts car, and after I took its engine out I decided that was going to be my EFI engine. Built the fuel rail, got the engine all clean and shiney, ordered new motormounts, and about the second week of april I did the engine swap and permanently removed the CIS setup from the fender well. After a few days of setup, a bit of wiring, and some timing issues (backwards distributor oops), she fired on EFI. That was a great day. The car has been running well ever since, except one minor issue (to be covered later) with the MegaSquirt ECU.
Its a small ECU, at about 3x6x1.5, but really does a big job. Its a fuel control only ECU, which means the factory ECU is still in place controling the ignition. Cost is about $130 and it comes as a bare circuit board and a pile of electronics. Takes about 4 hours to solder it all together and test on the test board (sold separately). Inputs are RPM, Manifold air temp (MAT), Coolant temp (CLT), manifold air pressure (MAP), throttle position (TPS), and O2. It controls the injectors, fuel pump, and idle air control solenoid. Works on basically any engine, 2 stroke or four, piston or rotary, gas or diesel, turbo or NA, odd fire or even fire, you name it.
Larry assembled the one for my car in a few hours, spread over 3 days, and I installed it in the car in about an hour. Takes about 5 minutes once everything is hooked up to get the car to start, and from there it only take a few passes down the road to rough tune it. Fine tuning is like fine wine, the longer it takes the better its tuned (for the most part). I did have one issue though, the injector driver control circuit had a minor melt down because of an overheating problem. Took just a few minutes to solder in the new part to replace the old melted one, and this time it got mounted to a nice heatsink to prevent that from hapening again. Since this fix I have driven the car all over, in rain and shine, for about a month now without a hitch.
The fuel rail was an interesting experiance. I started off by replacing this CIS injector cups with the EFI injector cups, then I stuck an injector firmly in each cup and measured the exact spacing. Then it was off to Home Depot in search of useful stuff. What I found was a piece of 1" sqaure tubing (has four flat sides instead of being round) in a 5ft length for about $2. This was then cut down to the measured size of the injector spacing between cylinders 5 and 1, with about 3 inches added on each end. Then I got 2 Porsche 944 fuel rails that were unndeeded in the shop and but the injector bungs off with a hacksaw. But how to attact them? Well I knew bazing would work well, and I know how to solder (even propane torch plumbing style) so I figured I would be able to braze, except I was unsure of how to safely work the Acedaline/Oxygen torch as I had never used it before. After a re-assuring that its hard to screw up bad enough to blow up the gas canisters, and a crash course on whats-what I was off. I first cut off 2 short lengts of the spare rail material and brazed them together. Not so hard! So after drilling the holes for the injector bungs to fit into the rail, I brazed each in. Then I polished it up with the bench grinder mounted wire wheel, and checked for obvious holes, many of which were found. After fixing all of the obvious ones it was time for a more difficult test. I mounted the rail in a vice at an angle so liquid would flow from one end to the other, and with the injector bungs facing downwards. Each bung protrudes into the rail a bit, so carefully poured liquid would flow arround the bungs, but not out of them. Then I got some air conditioning dye, which is a special type of esther oil that glows bright neon green under ultraviolet light, used for finding leaks in air conditioning systems with a special ultraviolet flashlight (which can also be used to give yourself a tan, and cancer for that matter).Out with the lights, on with the special flashlight, and then start pouring. It took a few seconds for the oil to seep through the nooks and crannies, but it did eventually, and it revealed a bunch of tiny leaks in each bung. More brazing, then ultraviolet tests, them brazing then testing etc. After getting every leak I could find I brazed the fittings on the end for the presssure regulators. Back to testing/brazing. Now after it was all done I plugged in the injectors and took the rail out to a car in the parkinglot and hooked it up. A few off/ons with the key to build pressure, only to find one of the end caps was leaking. Fixed that, and viola a perfact homebrew fuel rail. Picture to come soon. I also hope to build a new one using all the info I learned on the first one, and I'll get a bunch of pics during that making of it.