Another 911 Turbo CIS to EFI conversion

This is a very special car and customer for me. Many years ago when I was in my 20s, longer than I would actually like to admit I had the pleasure of building this car from stock to not. It is still owned by the same customer who has remained loyal to iA as well as a good friend.  I always thought this was a great car for many reason. First of the color scheme is awesome if you are in to the not like everyone else setups. The Metallic gray paint even after all these years is still stunning, but put it over a army green interior with sport seats and leather touches on everything and you have a very stunning car. Certainly not for everyone, but I am one that appreciates the uniqueness.  


The car originally was just a stock 3.3. It had a set of headers and a Ruf 5 speed standard clutch setup. We took it in my garage no less to 487HP as document on a Mustang 500SE dyno in Michigan. The car remained this way for 12+ years. I actually forget how long it has actually been.


When our EFI kit was released he sent the car back to us. This time to rid the CIS and let me touch the car with a little electronic magic. The new system included our full EFI package of SM4 Autronic ECU, Custom rails and rising rate fuel pressure regulator, Oil temp sensor, Intake air temp sensor, crank sensor, hall sensor that is custom fitted with in the oil sump housing, map sensors, one for intake pressure the other for ambient air temperature.  We had originally twin plugged this car and ended up using a CDI500 Autronic expander and 6 double ended M&W coils. We then custom fabricated a series of high performance plug wires and hold downs. Lastly the turbo was swapped out with a newer unit and a custom inlet track was made since the original ran through the airbox.


Many hours was spent tuning the car. If you have read my tuning post before you know I am not kind when it comes to tuning. I do not believe in the sweep and tune method, rather I hold a specific kPA and RPM block on the dyno and tune that specific cell. If I have 150 cells well I hold and load all of them. This is just for AFRs. When completed I then go back and do this with timing. The proper number comes into play when the timing has maxed the TQ figure for that cell on the dyno. Once this is accomplished the tuning is complete on the dyno. We then move to the second to last phase, tuning on the street. Tuning on the dyno only gets you 90% which for most tuners is fine. Not for us though.


I wake a sat morning and head into work. I stick probes here and there, an inverter and splitter for the cigarette lighter and another batch of 12 volt accessories find their way to the power source. Some tape here and there to keep things from flapping in the wind and I head over to Karl’s.  


His job in this game, drive the car and give feed back while I sit in the passenger with the computer on my lap. I watch AFRs among other readouts and make adjustments based on them and what I feel and what Karl is noticing behind the wheel.


Once this phase is completed we then move to the cold start up. Can it start cold, can it maintain an idle cold and can it be driven within 15-30 seconds of start up. Again, all these sensors allow me to judge what the car needs and what it is doing to make it as streetable as possible.


When the project was all said and done, we made 511HP at the crank as compared to the original 487 and we did it with .2 less bar.  

We also even used it for some ads!







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