80mics is not a normal one time dose, just to be clear. He means a normal DAILY dose. That's four to six tabs a day.
Start with 60 mics a day, divided into three doses, at least two hours apart. Add 20 mics every two or three days until the sides are too much, then just stay at that dose until it stops working.
Your top dose will be an individual thing. I cannot recommend a top dose. Mine (when I used clen, which I no longer do) was a huge daily dose. A dangerous dose, really. I used it for months on end. The crash was horriflic. I was really REALLY ripped and strong.
Clen adds strength in high doses, but the cramps will be horrible too.
Hope this helps.