Smart Fortwo 2009 CDI Turbo

[Mjolinor]

I reckon my car is not boosting soon enough. I have only had the car a few months and have been sorting lots of bits with it. No fault codes for a while now other than over boost when I hammer it.

The problem I have is that the gear ratios seem too far apart. I know that mid 2009 they changed the gearing on the box when they increased the power from 45 to 54 along with fitting the DPF and associated crud. This is a 54.

Having run the car for a while I am sure that the turbo start revs is too high. In the attached graph you can see the four points where the turbo starts working, this coincides with 2300 revs and given that this is red lined at 4k it is surely too high.



Blue > boost
Yellow > RPM
Red > Speed (km/h)

Can anyone suggest anything? There are no air leaks and the profile of the boost is not the same as you get with an air leak anyway.