using a 1/4 mile calculator. for a car with 110whp.
weight with driver - estimated ET
2500lbs - 16.49 seconds
2600lbs - 16.72 seconds
2700lbs - 16.92 seconds
2800lbs - 17.14 seconds
2900lbs - 17.34 seconds
3000lbs - 17.53 seconds
now remembering this is for the 1/4 milie we would need to adjust.
10.75x1.55=16.66 seconds. 11.27x1.55=17.46 seconds. so thats a .8 second difference.
so about .2-.3 of the .8 seconds you slowed down can be attributed to weight. then of course there is rotating mass with the wheels which can probably attribute to another .2-.3 seconds and the rest could be factors like launch rpms, how much spin you had, etc..