Will this damage anything?

[RCHabit]

I just put my emaxx together,
I have an 8xl Fiegao, mamba max ESC, and 2 7.4 lipos for 14.8V. I took it on its first run and was a little disappointed on how fast is was. I thought it would be faster.

The question is, I have one 11.1v lipo lying around. If I hook up one 7.4 and the one 11.1v for 18.5V will that hurt any of my components? And would it wake it up, for a little more speed?

Anybody have any recommendations on a more explosive motor. I want to keep the mamba max ESC and I have 2 7.4v lipos and a one 11.1v lipo to use in any combination.

Thanks