I recently bought a AEM failsafe gauge that reads wideband O2, boost, rpm and can datalog. The gauge also has the ability to ground a wire when the gauge detects a lean or overboost condition.

I'm wondering what is the best way to use the failsafe feature?

Thoughts have been:

1: Install a normally closed relay inline with the injector power, so technically this would be a fuel cut when the unit detects trouble.

2: Install a normally closed relay that would cut the signal to the leading coil, or power to both coils? Engine would still be receiving fuel which when ignition returns I can imagine might be very bad... But doing just the leading coil, wouldn't that just retard the timing a lot and kill power?

3: I could tie into the ECU for a boost control solenoid, not sure how I would do this or if it's a good idea. Or if any of this is a good idea...

I've read other guys cutting power to the ECU all together, that doesn't seem smart either.

Engine is a 13B-REW

 

Seems like usually the most straightforward way is to install a relay on your boost control solenoid if you have one. This way when your Failsafe comes on you can have it turn on the relay and have it run off wastegate pressure.

What EMS are you running, you can probably also get it to work with an input on the EMS to have it cut boost or add fuel trim etc.

 

Thanks for the input, I'm running a power FC. Do you know if there is a way to make it pull timing or add fuel?

I don't have a boost controller setup right now but I was worried about a spike as well; or a stuck wastegate or boost creep etc that may not be controllable. Sounds like the fuel cut to injectors may be a bad idea as well.

Maybe add a solenoid to pop the wastegate off the vacuum chamber? I don't know if that's smart either if it causes the turbo to overspeed/spool.