The vehicle is 100% hardware complete.
We weighed it and we are at least 10% under our target weight!!!!!!!
I'm not going to publish the weight until I can repeat the measurement, with a better calibrated scale,but this gives us significant performance margin for reaching 180 seconds!
The target weight with payload was 326 lbs.
The target empty weight was 271 lbs
The actual empty weight 230 Lbs.
My actual empty weight is 15% under Budget!!!
In order to do the 180 seconds I need a realized in flight ISP of ~152
As John Carmack rightly points out it won't be as high as I expect or wish.
The theoretical ISP for the pressures and fuel combination I'm using is 227
So I need to realize 66% of theoretical.
This is with tanks 90% full.
If I go to tanks 97% full I need an ISP of 145