Is there an electronic speed limiter on the BA 323 Astina?

[Inconcinnity]

My brother in law has an early 1998 Astina with a BP DOHC and manual gearbox that he uses for rallysprint and rallycross. When he gets onto a straight it accelerates well until it hits 160kph (100mph) at which point it suddenly (jarringly) hits a wall and stops picking up revs. The car should be more than capable of going faster (he used to have a Ford KF Laser/BG 323 with the BP SOHC that had a higher top speed) so we're scratching our heads. There's nothing mechanically wrong as far as we know, he can run it on the limiter all day in rallysprints with no issues. It's just when it reaches 160kph it feels like there's an electronic cut.

Anybody have any idea what could be going on?

 

[tweety2300]

Some got the speed limiter and some didn't