how far can you push a 5 speed gearbox hp wise?
 

hey folks... i have an sti import with the ra close ratio group n gearbox in i think... i know people say 400hp is the limit for the gears but if i was to have 2 boost settings, one for just under 400hp and one for lets say about 450-500hp to use at santa pod, would the gearbox give up on me or would i just have to be careful not to use it above 400hp all the time?

Its not bhp that breaks the gearbox but the torque, I would say depending on what year box you have plays a big factor, I wouldnt want to push anything classic over say 320lbs on a pre 99 car and 340lbs on a 99/00 car, supposedly the new age 5 speeds can take a little more but probably not much, STI boxes are slightly stronger on the classics though hard use will kill them quickly.
For the sort of power your looking at I would suggest a PPG or 6 speed box, a fully built PPG will set you back around 4.5-5k, a 2nd hand 6 speed will cost you around 2.5k with the rear diff (the 6 speed is stronger btw ;))

Tony:)

aww man that sucks... its a shame to have to fork out so much to protect the car before adding the big power... will just have to wait i suppose :cry::cry::cry::cry:

Just buy a new age STI, for the cost of a full rebuild and that gearbox you get a newer car with the capability of running 430-450bhp all day :D

Tony:)