I Just picked up a 93 Honda Civic Si 5spd, and noticed when letting the car rev past 5 on the tack, She really picks up, u can feel the difference right away almost like a passing gear in an automatic. Is this normal for this car. I've had crx's before and they never did this. Any info is appreciated.

 

Yes it's working properly. That is the "VTEC" feature kicking in. It opens the valves wider and sooner to improve performance at high rpm. Not all Civics have a VTEC engine.