There were a number of errors on this thread and before they were rectified the thread was closed.
1) If the fuel rail pressure is increased during mapping as it often is then the trip computer will show an improved fuel economy. There may well be an improvement in fuel economy but not to the exagerated extent shown on the trip. For accurate consumption, brim the tank on level ground, clock the trip distance, rebrim on level ground and calculate the mpg. Divide litres by 4.54 to get gallons.
2) Adding water methanol injection, properly set up WILL improve power produced. Historically on my Wife’s car, 12-18 bhp. It was claimed there was no power to be gained from water methanol injection but the person making that claim had previously posted elsewhere regards the gains from water methanol on his own car.
3) The depth of the intercooler core on the Elahi car is 92mm. The core size is generally determined by packaging constraints. Providing the core is large enough to do the job in hand the actual size is very much secondary to other considerations. Efficiency, pressure drop across the core, construction method and shape/fitment.
4) The core for the pre-facelift car, ( Elahi’,s) is different to that for a facelift, ( my Wife’s) because of packaging constraints. The one on the facelift is taller but thinner. They both do the same job efficiently. Selection of the right intercooler to gain maximum efficiency has a big effect on the engine’s overall performance. Fitting just any intercooler kit, particularly on the basis of cost is likely to result in substantially less than optimal results. Both these cores are tested by the manufacturer to over 700 bhp on petrol applications and both these cores are tube and fin construction.
5) The point at which O/E injectors max out will vary greatly, car to car. In part it will depend on the efficiency of the setup and the fuel rail pressure. On my Wife’s car it is somewhere well in excess of 250 bhp and onElahi’s car it is somewhere in excess of 240 bhp because that is the power figure he has produced up to now but how far in excess of that figure is not known. Unless the injectors are maxed out no more power will be gained from changing to injectors with greater flow. Injectors that are greatly oversized are to be avoided.
6) On a diesle the injector spray patern is critical. It will effect power, emmissions, fuel consumption and engine life. For that reason I decided against renozzling and went for modified injectors which worked out at +19%. I had already calculated that for my purpose I needed +15%. Reworking the injectors is also less costly. Incidentally, Vectra 120 and Vectra 150 injectors are different.
I hope this information may assist some of you wanting to get further power out of these cars.