Oh, i see, I had no clue nacelles caused that much drag.
As for the clipping yeah, i do tend to clip engines when i get desperate for power, And well, then i came here.
Oh! Well, if clipped parts cause so much drag i'll try reducing the amount of intakes.
I tried modifying the craft a but it still doesn't seem to work for me.
Here's the craft file if anyone could take a look? https://www.dropbox.com/s/c4smkoa35xtwumm/IDS.rar?dl=0