Stay away guys!
Working in an industry where somebody asks - at least - once a year; can we use Ti fasteners, the answer is NO! Ti has about 60% the density of steel, but it also has about 60% of the strength, so there are no gains to be made there - you need a bigger Ti fastener to replace a steel one and on the whole you lose out because you need to make everything else bigger to take the bigger fastener.
Even worse, Ti - like aluminium, but unlike steel - does not have a fatigue limit. With steel there is a stress - about 0.5 Fty - below which the fatigue life is infinite. With Ti, the S-n curve is asymptotic to zero stress i.e. any Ti component, however lightly stressed may experience fatigue failure.
Generally, there are no Ti fasteners on F1 cars. Don't put them on road cars! MP35N Cobalt is another story!
Paul