In preparation for the libya-rally we did some testing adding more low end fuel @ low boost and it did help a lot but get a bit of smoke for 1 second if you floor it from zero to max torque request.
We also used the biggest turbo allowed for rally use with a 74mm inducer size compressor without the need for an inlet restrictor.
From the data it shows that the spool up of the 82/88 turbine with a bigger 1.00A/R is only marginal slower than the 74/83 and turbine wheel and TH 1.10A/R on sea level so inertia plays a big part but as the air gets thinning by gaining altitude this will chance and the 74/83 turbine will perform a lot better than it’s bigger brother.
The job for tomorrow will be to make changes to the software setting of the 13L Scania XPI race engine. The engine is now build to specifications and I did get data from the runs they made but the O2 sensor was not working so no feedback on that part on what is left on oxygen.
Also getting in correct data can be frustrating. There is a data logger getting data from the ECU and we also have the internal data from the ECU and it’s not a easy job to sync these and find out the data logger of the truck can not keep up with a part of the data stream coming from the ECU.
Than there is the thing that a race driver is not a test engineer. I want a pull from 1200Rpm up to the red line in 4 gear if possible. What do you get? A run from second gear to 5 gear up to 160Kmh where the speed limiter kicks in and a RPM drop to 2000Rpm by shifting gear only 800Rpm short of what I need on low end spool up data. Sometimes you want to reprogram the driver as well.
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For some time we now testing the 88/96 BW turbine set-up with a 1.15A/R and 0.93A/R TH.
The 1.15A/R will be on sale already and the 0.93A/R TH is something we build in house.
The 88/96 BW turbine set-up with a 0.93A/R TH work well on a 16L OE set-up converting more power @ less EMP but we did not find the time to prepare a turbo for the 13L XPI Scania race truck engine to find out if this turbine set-up can overcome the inertia of the increased mass compared to the 82/92 and 82/88 turbine wheel we normally use.
Also making so many changes in one go can make things complicated on what has been changes and why so one step @ the time for now will be better.