Turbo Speed Sensor

Hello everyone!

How do you guys use the turbo speed sensor on a race car. I mean, what do you do with the data. Is it solely to make sure you are not overspinning the turbo, or do you use to help with the sizing of the turbo, or using it on an actual boost map axis to open the wastegate and slowing down the turbo if needed, etc…

I’m working on a friend’s rally car equiped with that sensor along with a turbo restrictor, and I’m just curious on how other uses it.

Let’s discuss!

Frank

It depends a bit on what other sensors you have and how accurately you can model airflow, also if the engine is otherwise strength limited or knock limited. The most basic is as a diagnostic/fault finding tool just for logging to identify potential leaks or restrictions if behaviour changes or confirm modelled engineairflow. Ideally minimum active strategy will be wastegate control to avoid overspeed. More complex strategy without other sensors may be using it and/or target boost for rpm vs boost/turbo speed mapping to avoid unnessessary pumping loss/charge heating on a restricted intake/when approaching choke flow/speed limit of the turbo. If you are also running a differential or absolute sensor between atmosphere/restrictor/turbo inlet and know restrictor flow behaviour you can target post restrictor target vacuum/max turbo speed so you are getting the most out of the available air/fuel without additional pumping loss & heat generation.

Thank you Michael for your reply. We are planning on adding MAP sensors in the inlet pre and post restrictor to get some data and make sure we are not making the turbocharger works outside its efficient range. He also runs an IAT pre intercooler and post intercooler, and the pre intercooler shows temps over 100deg C in boost, post intercooler was showing around 25 deg C on the dyno. Never ran a pre intercooler IAT sensor before so I kinda felt that these temps were high due to the turbocharger working too hard and pumping heat more then it should. I’ll post the results here when I have more data!