1994 3.6 Turbo EFI conversion 516 Rear Wheel HP!
This is a special car for us. Every year for the last 6 years this car has been brought to us with a project in mind. It all started with a call to us and a call to Ruf. 3 weeks later we had the car at the shop. This is a 1994 3.6 turbo. This was the only year that the car supported a 3.6 in a single turbo configuration and CIS. The first round of mods included exhaust, turbo, cams, engine work, valves, head studs and so on. The car came back the next year for cosmetic changes and the following years after. Its last visit to us had big mods again in mind and required as much work as the original engine build. The car was finally going to rid the 30 year old CIS (constant injection system) and update to a more modern EFI conversion that would allow more control with the latest technology being fed information by my laptop. For this project we used an Autronic SM4 ECU. We pulled the motor and inserted a set of cams that would allow us a little more top and with the proper tuning yield a very linear yet quick power band. We then fitted a custom Garret GT35R and all the special plumbing required to make a turbo like this live an oil cooled only environment. The car took many twist and turns during the project but the finally we got it on the dyno.. After 3 hours of tuning I was able to accomplish an astonishing 516Wheel HP. This was up from the original 375 wheel HP that the car saw when it came through our doors. Conversions like this are not easy and require many changes and a knowledge base that goes beyond simple engine building. You must have oscilloscopes, meters, dyno, tuning equipment and probably the hardest to find….a laptop with a 9 pin serial port! The method we tune for the on looker is nerve racking. Imagine strapping your 100K Porsche to the dyno and then holding 1 bar of boost while the exhaust glows fire red and I sit with the laptop in my lap adjusting AFRs. I go through every KPA band and set all the AFRs at every RPM/KPA band. From there we do the process all over again, this time with timing. Once we hold the cell and have the max TQ then we know that the max the engine can make has been achieved. Once this process is complete then comes the hard part, making the car start, cold, hot and drive down the road without bucking like a wild horse. Wires are strung out through the car like a terrible science experiment. Literally I have cords taped to the windows coming in the car to my laptop, AFR meter and so on. Often at the lights the neighbors sitting next to me will ask what all the wires are for. The funniest thing is to see the look on peoples face at 6:30 in the morning in rush hour as I sit with the laptop in my lap driving. There is no substitute for drivability then on the street in rush hour. You can make a car 90% tuned on the dyno, that last 10% takes days!
The end result is always fun for me. I quickly called the customer on completion and said you want to hear this thing? A quick retort from the owner who all the sudden sounded like a school kid getting ready to be released for summer vacation. I asked “you ready” “YES” replied the other end. “Ok, here we go!” all you can hear is waaaaaaa womp! “That’s it?” Questioned the voice on the other end” I shot back “Yep, that was all of first gear and half the tires down the street” I chuckled. He was ecstatic and just kept saying that thing sound serious! So as of Monday it will be on a big Green truck headed home for a new year of adventures.