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Hello all, I joined HP Academy last fall in preparation for installing and tuning a VEMS engine management system on my 1986 Porsche 944 Turbo.

I am a professional Porsche/BMW technician with over a dozen years of experience in diagnosing and repairing all sorts of induction systems, from carburetors and mechanical fuel injection to '80s Bosch EFI systems to the latest direct injected cars. While we work on a number of fast and modified Porsche 911 Turbos from all eras, I had a limited amount of experience with aftermarket EFI systems. One of my favorite aspects of my job is learning new things every day, and I wanted to find a way to learn more.

Through the miracle of Facebook's targeted advertising algorithms, I began to see HPA posts populating my feed. I was impressed by the content, so I decided to sign up for some courses. So far I have completed the EFI Tuning Fundamentals and Understanding AFR courses, and am in the middle of the Practical Standalone Tuning and Boost Control. While I was quite familiar with familiar with most of the concepts detailed in the basic courses, I was impressed by Andre's straightforward, logical approach and how these concepts are relevant in the context of high-performance EFI tuning.

As for my 944 Turbo, it has been both my primary means of transportation and track car for over 10 years now. While the suspension has steadily evolved into full race-spec (double-adjustable coilovers, spherical bushings everywhere, geometry-modified front uprights, etc), the engine has remained stock for reliability's sake (and because of California's draconian smog/emissions test laws!). The original bottom end has over 170,000 miles, with over 10K of those being track miles! I have a spare engine on a stand to build and fortify for reliable track use, but I wanted to start tuning my existing engine as a guinea pig so there were no surprises once the new engine is installed.

I chose the VEMS system as it looked to be a good middle-of-the-road setup which had all of the features I wanted (and it plays nice with the 944's old-school/noisy inductive crank/ref sensors that use the starter ring gear and a single stud, respectively). Plus, a fellow in Estonia offers a complete plug-and-play setup for the 944 Turbo and has great tech support! Installation was quite easy, and I installed a Tial F38 wastegate and MAC boost control solenoid at the same time. I adapted the factory airbox for a clean look, and to make sure that everything was easily reversible for emissions testing purposes.

Initial tuning with the VEMS is relatively straightforward, and it was much easier once armed with info from the HPA courses. After a decent amount of road tuning, the original engine/turbocharger setup now offered much crisper throttle response than the old Bosch DME/vane airflow meter, along with a nice bump in midrange torque, even at the factory boost setting.

Next, I installed a trick Evergreen K27/K26-6 with modern "billet" compressor wheel and lightweight turbine wheel, along with a 3" downpipe and mid-pipe. I also installed Siemens 800cc injectors and a Bosch 044 fuel pump to ensure adequate fuel supply. Again, all bolt-on and bolt-off per my requirements! Retuning the VEMS for the larger injectors was a breeze.

While my factory airbox and intercooler are likely restricting things, boost response is amazing, with positive manifold pressure at 2000 RPM, and my wastegate spring setting of 0.7 bar boost pressure achieved at 2800! I will get into PID boost control soon and take it to 1.0 bar.

As for other cars, I also have a 1973 BMW 2002tii, which retains its original Kugelfischer mechanical injection system, along with a salvage yard rescue 1981 Alfa Romeo GTV6, which runs great on its Bosch L-Jetronic system (VEMS is probably in its future :).

Thanks to Andre and crew for a great experience so far!

Hi Chris, nice and detailed post of your proyects, I am sure with your mechanic background and all the knowledge you are going to catch here in HP Academy

you are going to enjoy a lot your tuning experiences and have very good results . Nice cars you have...

Hi Chris,

Nice write up, I don't suppose you'd fancy sharing some pictures in a build thread?

Hi Chris,

Nice setup! I live in Northridge CA and I own an 1984 Mercedes 500SEC, I am doing the same thing to my car, Vems ECU for EFI conversion !

I love me a nice 944. Something about that wedge shape, it just seems to right, not to mention the fender flares. If you've got the time, I second Chris's suggestion of popping up some pics in the build-threads section, or even a link here to any other info you've got online about the car, sounds like a really great build with a good story behind it :-).

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