Nothing has changed mechanically in years. So. No new parts to blame.

This has happened twice now. Rev the car out under full boost in 2nd gear and everything goes to hell. Seems to be running on 1 or cylinders for a few seconds and then dies altogether. Let it sit for 10 minutes and it fires right up like nothing ever happened. Would a bad coil be intermittent like this? I cannot replicate it when I try but I have been left stuck in the middle of the road twice. Stock coils on HKS box.

Coil?
Cam Angel Sensor?
Bad Flux Capacitor?

 

Check coils and check plugs, those would be the first suspects

 

Is it going lean? could be fuel supply issue.

 

Agreed with above. Check the coil packs and see if you are getting any misfire codes.

 

Try pulling the hks box and run just the stock stuff and see if it falls flat.

 

My vote is for the hks box as well. Aside from that, crank sensor issue is possible.

 

Could be a lot of things. Is your CEL light on?

It could be your coils, fuel pump, or your cam/crank sensors.

How many miles do you have on the engine. And, when was the last time you did the timing belt.