Alastair's Porsche 928
From M-Tech Automotive
Contents |
In the beginning...
Alastair brought his stunning 928 to us when it started developing problems with its Mass-Air-Flow sensor. The cost to replace this with genuine Porsche parts meant that with considering the price for fitting and mapping one of our stand-alone systems, it seemed it was time for us to work our magic yet again.
The first thing we did was offer the car in its standard trim up to the dyno to see exactly what we were starting with:
PIC
Now we had an idea where we were starting, we had to decide where we wanted to go.
The Plan
Alastair chose the following tasks for us to undertake, to get his car running as well as it looked.
- Fit V3 EMS, and map on our rolling road.
- ASNU the Injectors.
- Fit a 36-1 for the ECU, and custom bracketry for the sensor.
- Do away with the distributors and fit wasted spark coil packs.
- Remove the belt driven cooling fan and fit an electric item.
The Work
Trigger Wheel and Mounting Bracket
First we had to get a clean trigger reference singal for our V3 engine management system to use to decode when the engine was at TDC. The Porsche uses an odd 100-1 triggering system that simply wasnt compatitable with our V3, so we opted to mounbt a 36-1 (Thats a wheelw ith 36 teeth, with one removed) onto the front pulley, and then fabricate a bracket to hold the VR sensor that would detect these teeth, and feed this information back to the ECU.
We also then had to remove the exisiting cooling fan arrangement, and modify the front pulley to suit the trigger wheel. The trigger wheels centre was lathed, and becuase the Porsche lacks a form of woodruff key to locate the trigger disc, we drilled a small hole in which we could insert a locating grub to align the trigger disc with the crank shaft, regardless of when the front bolt is tightened etc.
The Results
After mapping, the car made a healthy 280bhp, with plenty of torque. Alistair is now happily driving his pride and joy with the relibaility of aftermarket EFI!
