Try uploading your images to another file storing site.
I looked up the url for your images and they all are trying to link to the photos on gtr.co.uk.
This won't work due to some of the privacy settings or whatever of that site.
Pull head off and look at gasket. I'm gonna say you have a break in cylinder 1/2.
Send head off for machining get new gasket and some head studs.
Bobs your uncle. Maybe
Lol. How can it break traction and jerk back and forth.
Axle tramp is like a hopping sensation in the back.
Sti and gtr are WORLDS apart in how they drive