What will a 2lbs upper give you in the 1/4? (stock computer)

When I was stock my best was 14.1

I added FTVB, K&N with 2 hoses going to front bumper (not ram air), slapper bars, and still was at 14.1. I know the mods I have will not make a big difference in the 1/4.

When I added the upper I went 13.6. All on F1s

Thanks

 

i dont know how much hp it gives,but i could tell a big difference when i put on my 2# upper,then i put in the pred tune BIG difference