Yes it`s by specs and at least it has been very limited what you can change mechanically(I don`t know how it is with these new cars) so it would seem a bit strange to transfer something TMG designed to another company when they are quit limited in what they can change. I read Mercedes has a completely unique combustion chamber design in their F1 engines so maybe this is what TMR is after.. If Ilmor is part of Mercedes that is