I have an Impreza WRX 2.5T 2006 which I have collapsed the gearbox.
I have 350 hp so I need a sprocket-set or a STI gearbox.
Does anyone have experiences on this?

 

I do.

I had a 360/400 WRX 2.5 (2006) and 3rd gear blew on me.

I went for an STI gearbox (from a bug I believe), had to convert the clutch and ran an exeedy stage 1 without any problem.
Whilst at it, you may as well go for STI rear diff, shafts and hubs too.

You will need to modify the neutral position switch too - you'll need to add an inverse relay as the older STI boxes are different to 2006/7 STI boxes.

I have a relay from my gearbox to my ECU which does exactly this (12v feed from cig lighter).

Ecutek doesn't have an option within software to change this on our cars.

Lee

 

ohhhhh........expensive. bite the bullet now. false economy putting another 5MT back in.

 

Ok, but I have heard that I can buy gear from PPG Australia.
Then keep it as good as the 6 speed?