Rev limiter
 

I have a 1987 RX-7 and it has a rev limiter of 4 thousand RPM and it is very bad for my racing life. if you know how to remove it or adjust it please email me at viper050@hotmail.com

This is most likely caused by the secondary injectors not firing. At 3800 RPM the secondary injectors come online and the primaries drop back to half the previous duty cycle (it goes from primary injectors only to the two sets sharing the load). If the secondaries aren't firing, the engine will not rev past 3800 RPM.

It could be something as easy as the clips having come off the injectors - the injectors you can see with the intake manifold on are the secondaries.

-=Russ=-