I take 300-450mg, although my tolerance is quite high, and something I should mention is you risk seizures on Tramadol at high doses. Especially after 400mg.
I think a good starting dose would be 200-250mg, if you felt nothing on 100mg. My advice would be to take 100mg, wait 30-45 minutes, if you feel nothing redose another 100mg wait 30-60 minutes and you should feel something. If you do and it's not so intense, you could always add another 50/100mg to total 250mg or 300mg but I wouldn't advice going over 400mg so early on as seizures are a huge risk on Tramadol.
Also, Tramadol for me and many others takes hours to feel the actual 'buzz'. Codeine I feel after like 15-30 minutes but Tramadol I sometimes don't peak until about 8 hours into the buzz. But you should certainly feel a light head, itchy and maybe even sedated after about 1 hour of taking the dose.