Overboost protection based off RPM

[93supercoupe]

Had a friend (forum member) fold a rod in his motor this weekend due to wastegate failure. That started a discussion about why and what happened.

As we know, if you create a ton of torque with a power adder with out enough engine speed, the rods take a beating. In our friends situation, hes got a relatively small turbo (borg 52mm) on a 24v BMW engine. Something happened to the wastegate where the car saw 25+ PSI below 3500rpm and it folded a rod.

In his case, 25psi wouldnt have been catastrophic had it come in a little later.


Currently, the boost protection is a single setting. What im suggesting is a just a single line graph that has boost VS engine speed. So a graph that might look something like 1000RPM-4000 boost protection happens at 200KPA, 4000-7000 is 250KPA (but have multiple points obv).

Chime in with thoughts

[CRSTune]

It kind of already has that kind of protection available as closed loop boost control. Once enabled, a boost tolerance parameter can be set that trips overboost protection when you're a certain pressure above your target pressure referencing the boost target table.

Even if you're not using an EBCS, you could still enable closed loop to take advantage of that feature alone.