pipelining

Hi!

I would like to use webbot as a test tool for processing pipelined HTTP
requests.
As I read pipelinig is done by webbot without any recompilation.
But I did not see any pipelined reqs when I was capturing traffic with
Sniffer. 
I run webbot on NT 4.0 aganst my local Apache server(W2K system).
What I need to do to use webbot for this kind of test? How can I force
pipelining?

Thank you.
Karina