It's doing its job then in protecting your engine. So although its hitting boost cut that's not the issue the hot temps is.

Can't remember if you've gone FMIC or not?

If so are you still running the scoop? Mine always struggled with temps there in the summer my plan was to delete the scoop and have a flat vent in its place.

The problem you have with an FMIC AND the scoop in place is the warm engine bay air cant escape. You have warm summer air being forced into the engine bay via the hood scoop which is stopping the hot air in the engine bay escaping which means temps just climb (including intake temps).

If you just put a flat vent instead of the scoop you improve the flow of the hot air out of the engine and temps will drop significantly.

This was an issue on a Time Attack car I worked on. The first lap or two were ok but temps started to climb after that and for 20min sessions that was no good.

Although we didn't have anything to replace it with we just removed the scoop completely and the problem went away. It was a cheap fix. Certainly worth a shot in your case.

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605whp
Quarter Mile in 10.9 seconds @ 135mph /217kph
0-100 kph 3.2 seconds