Observation:

Redlining the Turbo and inducing the throttle limiter feels like stepping on the brakes. All too often while doing a little racing, 6500 RPM's come up and the Turbo's acceleration is cut off...abruptly.

Makes me appreciate how hard the Turbo is accelerating immediatley before the cutoff.

 

Happened to me the first time I took it to the track. The stock exhaust note is so low it is hard to hear the engine with a helmet on.

 

The TB does close.

 

The cut off is too sharp under other conditions. If you touch to brakes while turning with a little gas the engine cuts out. I'm glad you mentioned this about the redline, that sounds dangerous at the track.