Help identifying this engine sound (injectors?)
 

After installing an Innovate Motorsports supercharger on a friends BRZ, noticed this sound - consistently happening? It turns on like a switch once the car warms up and gets to it's stable low idle.

You can hear it specifically start at exactly 1m 27s in this video I took today.
[ame="https://www.youtube.com/watch?v=KeNAoty-5Pk&t=1m20s&hd=1"]BRZ sound (D4-S injection system ?) sound changes at 1m 27s - YouTube[/ame]


My first guess is it's related to D4-S injection system - but I couldn't find anything specific here --> http://www.treadstoneperformance.com...brz-explained/ that would explain the sudden switch making the sound we are hearing.

Regardless, can anyone else confirm this is "Normal" for this car. We are probably just being over sensitive to everything as we just installed the SC and a little anxious/curious.

Thanks in advance :thanks:


Video
[ame="https://www.youtube.com/watch?v=KeNAoty-5Pk&hd=1"]BRZ sound (D4-S injection system ?) sound changes at 1m 27s - YouTube[/ame]

Yeah, that's normal lol I think every boxer engine sounds like that actually.

And I'm saying it's normal because a friend of mine drives an FRS and I also have BRZ and they all make that same sound.

[ame="https://www.youtube.com/watch?v=3lzXgGo9wNU"]2013 Subaru BRZ Limited In Depth Tour, Engine Sound, Exterior and Interior - YouTube[/ame]

Go to 2:35 you can hear that same sound lol you're fine.

Yup, this is a normal sound. I am also very anxious over every noise this engine makes. It gets to me sometimes :/

Use a stethoscope to pin point it.

Direct Injecion

Thanks everyone for the responses.
Much appreciated.

Yep. Mine does it too. Normal.

I thought maybe some sort of solenoid retarding the DI system at low RPM (idle). But I don't know wtf I am talking about.

I am pretty sure that is the moment the DI pump starts pumping fuel. From a cold start the car starts off on the ports.

Might be wrong but at the very least it is DI related.

Normal, no worries.