How hot do the spices have to get to extract the most flavour from them please?

If its over 100C, does this mean that I have to add the dry spices to the hot oil (at 200C plus) before i add anything else containing water? 

Because as soon as I add water (like in onions or pastes) the temperature will struggle to get above 100C (and will probably be about 85C on a domestic hob) wont it? 

Will the flavour of the spices still be released ok at 100C and below?

I've been trying to replicate BIR curries for some 20 odd years now!. 

I've been invited into several BIR kitchens to cook my own meals and have befriended a couple of BIR owners and chefs.  I think my currries aren't far off the mark.

I can't believe that it has taken me this long to find this site!  There is some very interesting stuff here and I hope this site helps me to "put the icing on the cake", so to speak!

I look forward to participating in the discussions here, trying some recipes and tips and to offering some suggestions of my own!

Cheers all!