Here's the graphs from the mapping on the Dyno at Taylor Machine Services after the winter rebuild and repair work
The Engine was run with and without the fanbelt on, without the belt on made 22BHP more and over 10 Ft/lb of torque more.
The figures for BHP are slightly down on previous estimates but the torque figures are up. The change to 1.4:1 ratio rockers and shorter velocity stacks will have changed things somewhat anyhow. With the weight of the bus high torque is really what I'm looking for.
The thing that surprised me was how low in the RPM range power occurs, I had previously been shifting at 6,500rpm which is way too high and well into the power roll off. I need to map this against gear ratios to set exact shift points but the information here means that I can happily shift at 5,500rpm and set the hard limit on the ECU to 6,500 and prehaps set the soft clipping limit as low as 6,000rpm. If this works out well it should mean a significant increase in engine life as the stress of higher RPM running really does it no favours.
since these charts were done engine has been rebuilt and the top end set up differently, the rocker geometry has been altered dramatically and now makes optimum lift and higher top end. I think that the power lost from last year has been found. Although there has been very little track time so far this season the bus is running strong and looks on target to run better than last years best results. When i get an opportunity to get the bus on a rolling road i'll remap the fuel injection and get proper results.
As soon as I know i'll post them up here.
it has been pointed out that because the torque and BHP curves cross at the wrong point that the printouts I was given, as illustrated above, are complete nonsense. db september 2004