Under the list of crazy cars I have built over the years this is one of the top tier. This 86 930 was stout to begin with but was ready for more under the tail so to speak. We started with a 3.3 motor and threw anything we knew would make it strong, fast and powerful. The list includes knife edged crank, TBC pistons, dry lubed skirts, custom cams, extensive flowing and porting of the heads, larger oil pump, Raceware HeadStuds, Pauder Rods, dual oil cooler additionally the wastegate was moved via 934 to the rear and middle of the bumper with a zork dump tube. We used a 3.2 Carrera intake but the throttle body side of the intake an rotated it to the front. The intercooler was then cut apart and re-welded to meet the new angle of the throttle body. Additionally, the throttle body linkage had to be fabricated as it no longer was operating as a OEM unit. One unit pulls over and one unit pulls under. After this was completed I welded up a longer section of the throttle body shaft and ground it down to house the TPS. The head was tapped and fitted with a head temp sensors. This just scratches the surface of all the work performed on this motor.
The important part of any good motor is the brain to make it all run like you would want it to. For this I chose a MotecM48 Pro, M&W Expander and 12 double ended M&W coils. We then used a dummy dist and installed a hall sensor and wheel to calculate the ignition angle along with a mag sensor on the crank pulley.
My style of tuning has been discussed here before but just to recap the procedure is two part. The AFRs and set steady state. Each rpm and kpa plot is held with the forces of the dyno holding the car in place and at that cell. You then add or remove fuel until you achieve the AFR you want, then move to the next cell. The timing is done in the same way but rather than watching a AFR you are watching the the TQ. As you add timing the TQ will continue to go up, when it has reached it max TQ it will no longer make any more gains regardless of how much timing you add. Once complete, you move to the next cell. Now imagine this 50K motor screaming at 1.3 bar@7K RPM. Talk about nerve racking. One wrong move and you are back into the engine room.
This car weighed 2400Lbs and would haze the tires at 80MPH! The car would make 545 to the wheels at .7 bar and, well use your imagination what 1.3 bar looked like 😉