I must admit, Project 951 was taking forever to get going with its motor swap and, after it was ready, we were running into issues that kept slowing things up. Thankfully, Precision Motion-the guys behind the project's recently rebuilt engine-got the gremlins worked out.
While putting on some miles with the Link AFM piggyback system in place, it was difficult to get the car running right. Throttle response seemed a bit hesitant, especially when stomping on it, and the air/fuel curves weren't as crisp as before.
I contacted Vitesse Racing on the East Coast. Why I didn't get these guys involved sooner was my mistake. John Joseph is a real car enthusiast. Thanks to his engineering background, Joseph finds software development, turbo selection and performance enhancing second nature. He met another engineer, Terry Thacker, who also happened to be a car nut and had developed his own advanced tuning solutions. The two formed Vitesse Racing in 2000.
When Project 951 left Stuttgart, it was equipped with a vane air flow meter (VAF), in common with many European cars from the '80s. The DME, or ECU, uses the signal from the VAF to calculate load, fuel and ignition. It worked well, but when engine performance is increased drastically, the VAF becomes a limiting factor.
In Part Four, when we first upgraded the turbo, we switched to the Link piggyback system, which uses a manifold air pressure (MAP) sensor. The problem was that the software tuning made it difficult to achieve a perfect air/fuel ratio. Additionally, since it only tuned the fuel map, we were limited to the ignition maps supplied by the Weltmeister chips in the DME. The Vitesse Mass Air Flow (MAF) kit (which is available for BMW E30 M3, Porsche 944, 951, 944 S2, 911 Carrera and soon the 964) replaces the stock VAF with an MAF. The MAF operates similar to the VAF, but without any moving parts, making its response faster. Most modern high-performance cars use MAF systems.
1. Vitesse Racing blesses Project 951 with its MAF conversion and PiggyBack kit.
2. Our turbo is a Turbonetics 60-1 HiFi with a 0.68 AR housing and P-trim turbine wheel, but we'll be testing the smaller and more streetable 0.58 AR housing on the back side with Turbonetics' new F-165 wheel.
3. The Vitesse intake and MAF housing installed. The pigtail attaches to the factory AFM harness for an easy install. Power the red and ground the black.