Why is my raptor slow?

[Puddin]

So I bought a used 2011 700r it came with a fuel customs filter on it. My brother bought a 2016 700 and put a slip on hmf on it and his bike was fast so I decided to try making mine faster.After riding a bit I bought barkers duals, pcv with auto tune. Everything seems to be running great, I have more power than I used but instead of my brother beating me we are now tied. I dont get it, why does his stock 2016 with a slip on pull so much harder? Why after I pipe and tune mine can I not beat his? Is the 2016 that much better? Is it his single port head? Why am i not faster?

[09RappySE]

No, switch bikes and see what happens.

[Wreckless]

Check gearing also

[Puddin]

Stock gearing on mine, I guess idk what my brother has but I'd assume stock since he bought it off an old farmer. I have a 15 tooth front sprocket sitting here I could put on.

[gghouck]

Traction issue perhaps?

Are you like a couple hundred pounds heavier?