Originally posted by qitstrn
If you took your racing around a cone coarse. There would be alot of heat build up from being in boost but not cooling down. When you are in 5th gear you might be getting alot of air but that boost and heat build up from accelerating lets say through 3rd,4th and 5th. When you are in 5th you are not gaining much speed quickly. There for you will get the motor so hot it will melt a piston. When i had my LS tranny with my gearing the car would be capable of 170+. The problem is i could never reach that speed without breaking something. You dont want to race in 5th gear just trust me on this one or you will find out the hard way.
i dont know about all that happening from just one time. maybe if this is done repeatedly it can cause some serious damage but i personally have made multiple runs to 150mph with no damage occuring to my motor. obviously it all depends on how well its tuned and how high egt temps get. but like ron said this is definitely not recommended as the motor isnt the only thing on a civic not meant to go that fast