In Reply to: 1.5 hours enough for transit? Perth posted by daisydog on Thursday, 25. April 2013 at 06:56 Bali Time:
there is a lot of development going on around Perth International and you also need to allow some time for any unforseen problems.
There is a newish "by-pass" road now that takes some of the issues away from travelling on Tonkin Highway, but even so I think it's too risky.
You do not mention the time of day either, and this will also be a factor.
Book the earlier flight and relax.