smoking and loss of power

[jell]

Hi everone..I have a 98 Boxster and have just completed putting her back together, I took her over the local airstrip for a test run and stumbled on a problem.
While giving her a bit of stick on left lock the car bogs down on power then chucks out loads of smoke (not from the tyres) , On right lock it's sweet and runs perfect.
I was just wondering if anyone had any idea of the cause of the problem or if thay had herd of a problem like this before....Many many thanks