How much do you know about Ayahuasca? Because if you do not know the average time it seems like you've skipped doing proper research. I strongly suggest(and I believe many others will agree with me on this one) that you do extensive research on Ayahuasca. Start out by reading the
Wiki here on the Nexus. Then see what Erowid has to offer and perhaps google a little bit around.
I understand that you may be eager to use Ayahuasca but remember that you are using a substance that will cause strong hallucinations. You do not just want to jump into that unprepared. Taking psychedelics require a form of mental preparation combined with taking in information on what you are using, how it works, why it works that way and what to expect. The more preparation you do, the better. It will arm you against being overwhelmed and trampled by the experience. My first psychedelic experience was truffles / mushrooms and our 3rd man joined in last minute and without preparing himself. He had quite a terrible time and I had to put my own trip aside several times to calm him down and make sure his trip was a happy one.
I urge you to read this page first:
Using psychedelics safelyThe spice extends life.
The spice expands consciousness.
The spice is vital to space travel.