is there a hp diffrence with tailpipes vs. turndowns

[Chris_H]

I have been seeing a lot of messages lately with people talking about turndowns. I have been thinking about it a lot lately too, especially since these new slicks I have rub the pipes. My question is this: do you put the turn down right after the muffler, or do you shorten your exhaust some first? the reason I ask this is because my mufflers are about a foot at the most from my differential, and so I wouldn't have much pipe from the muffler before it has to turn down. What has everybody else done with theirs?

Thanks
Chris