Still tuning the Turbo Concepts

I’m continuing to work on replicating the boost profile that the car operated at with the BorgWarner K04’s.  In this effort I am mainly concerned with the top end boost so that I can compare the pre-turbine backpressure produced by the Turbo Concepts Stage 1 turbochargers with that from the other logged turbo’s.  The current state of the boost profile is shown below:

Turbo Concepts Stage 1 Turbos Boost
Turbo Concepts Stage 1 Turbos Boost

This tune started from a FrankenTurbo F21 tune that I used with the same hardware, aside from the turbochargers.  The wastegates on the Turbo Concepts turbochargers are set about 1.5 psi less than what the FT’s had, so I was anticipating some adjustments needing to be made.  The first few revisions were not generating the results I was wanting, so I went back and logged the boost developed at a variety of fixed wastegate duty cycles.  A sample of some of these are shown below:

Turbo Concepts Fixed Wastegate Duty Cycle Boost Levels - 50, 60, 70
Turbo Concepts Fixed Wastegate Duty Cycle Boost Levels – 50, 60, 70.

I suspect one of the reasons this effort to modify the tune is proving a bit more of a challenge than I had anticipated is on account of the unsteady boost curve.  I’d have expected a fixed WGDC to produce a straighter line.   I was concerned with the wastegates when I was trying to set the pre-load and was having trouble, the variations shown above further my concern about the wastegates on these turbochargers.