Will fitting a unlimited cdi unit race coil help top end speed on your motorcycle?

Yes, you're completly right. Fitting the unlimited cdi unit will do the most for your bike as this is what controls the rpm (revs per minute) the more revs you are doing the faster top end, with this you should expect an extra 7mph which may not sound alot but it's good. The race coil should give you an extra 3mph if that so 10mph more with just these two, not bad.