ballast

I'm working on a small model yacht (~40cm) and I was curious as to why none of the designs I found incorporate ballast inside the vessel and instead use a drop keel. Why can't a model have the ballast inside like tall ships use to, and if so, how would I calculate that? Also, I am in an area...

I have 2 extra Xenon HID ballast, which came with different size headlight bulbs. I was wondering if i get a H1 HID bulbs will it still have the same effect with the same ballast? The 2 extra ballast came with H7 size headlights. and the H1 are for my fog light which is smaller than the H7s...

I have 2 extra Xenon HID ballast, which came with different size headlight bulbs. I was wondering if i get a H1 HID bulbs will it still have the same effect with the same ballast? The 2 extra ballast came with H7 size headlights. and the H1 are for my fog light which is smaller than the H7s...

I have 2 extra Xenon HID ballast, which came with different size headlight bulbs. I was wondering if i get a H1 HID bulbs will it still have the same effect with the same ballast? The 2 extra ballast came with H7 size headlights. and the H1 are for my fog light which is smaller than the H7s...

I have 2 extra Xenon HID ballast, which came with different size headlight bulbs. I was wondering if i get a H1 HID bulbs will it still have the same effect with the same ballast? The 2 extra ballast came with H7 size headlights. and the H1 are for my fog light which is smaller than the H7s...

philips 160w sox street lightings does it require a ballast to start or just st8 forward 240volt ???

i need tips, sites, videos or anythin on changing this for the passenger side. lines dropped are Appreciated.