I know what I have done to my 99GL would never be allowed in historic rallying or racing, but it has been very enjoyable and worthwhile, my reason for this project was to get my humble 99’s power higher than that of a standard 99 turbo and to make it very user friendly and of course no turbo lag .
My first thoughts went to how and where to mount the crank sensor and 36-1 toothed wheel, I decided to have a custom crank pulley made so it would easily take the toothed wheel, I then just needed to make a simple bracket to mount the sensor. I needed to do this with the engine out of the car, because it is not possible to remove the pulley on the H series engine when it is in the car.
The ECU I used is a DTA S40, this comes with several maps from many engines so it is quite easy to choose something similar to your specification, I used a map for a 150bhp Ford Zetec, the other very useful feature with this ECU is the built in oscilloscope, this enables you to see exactly where the ‘spike’ is for the crank signal and to enter the degrees into the spark map. The car started and ran well, not perfect but enough to be able to drive it to the rolling road to have it mapped. It looks very strange to see a Ford coilpack where the distributor should be.
The result after a full day tweaking the map was to have a powerful ‘old timer’ that can be used very easily on the road and in traffic. The peak power is 167 bhp at 6400rpm and a torque of 141 lb/ft at 4800rpm, we could have taken the power above 170bhp but this is a fast road car and because I will be using ordinary unleaded fuel, it was mapped to a safe limit. An interesting note for those using carbs with trumpets, initially I had 40mm long trumpets fitted to the 45mm Jenvey throttle bodies, then fitted 90mm long trumpets and the torque came in 500rpm earlier which is very good, this sacrificed a few bhp at the top but it is worth it.
I have purposely limited the maximum rpm’s to 6500 because I am using standard valve train parts, except for the 44mm inlet valves, but on the dyno the power is still rising. The noise from inlet is beautiful and very addictive!
I just have one part that I need to experiment with, the 4-2-1 exhaust manifold, this is from MSS in the USA and at the time it was the only ‘off the shelf’ performance manifold I could find, the diameter of the primary and secondary pipes is the same and this is unusual, the primary pipes are usually smaller than the secondary pipes in order to keep the gas speed high, I will alter the primary pipes and watch the result on the dyno.