wel since the rider make a great part of the equation maybe!
but for a same rider the gsx-r will be faster!
full exhaust and PCIII doesn't bring the hp of a SV650 near a gsx-r!
There's different way of thinking:
yes i could eat a gsx-r at lunch with is sv in the twisties!
I can't follow one of my friend which had a sv650 before
lol but seriously... if your brother is an experienced rider, he may beat me in the twisties. But on it's gonna take more than a full exhaust and stuff to follow me on the highway / straight roads.