So on Saturday, I took the little car to Bob at Hayes Engineering for a Power Run to see what she is running in standard form. With only 1250 miles on the clock, I knew there was a strong possibility she wouldn’t be up to full power, but I wanted to have a ‘neutral’ comparison for once the car has been mapped so I can compare on the same rollers later down the line. The 595’s are supposed to be 160bhp, so I was hoping for about 150bhp, with room to improve over the next few thousand miles.
Here she is, ready to be run:
Once all strapped down and ready Bob did 3 runs. The best of them all was 142.9bhp, with about 165lbft Torque… Hmm…. A little low on what I was expecting, so no wonder I have been a little disappointed with how she has been going.
Here’s the graph showing Power and Torque:
However, one of the reasons I go to see Bob is he always explains what's going on, and this second graph really shows why the power is so low:
This shows Power against the Air Fuel Ratio. As you can see, at about 4000RPM, the AFR suddenly shoots down to 10:1 and the car is running very very rich. Bob even said he saw it down into the 9’s at one stage on the unit he had in the car, but the graph scale doesn’t go that low to show it! At this point, the power just sits at the 140 level and can’t go any more because so much fuel is being pumped in. At the point when the power curve stops increasing, if you instead keep following this with an imaginary line, you can sort of see that in theory it should keep going up to about the 150bhp mark which would have been more what I was hoping for. It is quite common for manufacturer’s to run the car’s rich for safety reasons, but I was quite surprised how much effect this has had on the car. With a good map, I should easily be able to get this sorted and allow the car to produce the power it should be.
It is a little disappointing, yes, but knowing the car would be a bit down to start anyway, and then seeing the AFR so low, explains why the car feels the way it does and is only producing the power it is.
I’m certain now that the car needs a remap, and with intercooler, exhaust and actuator at the same time to make the most of this, I should see some decent power and torque gains.