open exhaust???

[sick GN]

How much horsepower can I expect to gain if any by opening the dump on my 3" DP?? I ran a 12.6 @ 105 today and was just wondering if I could gain a little more by uncorking the exhaust. It is a totally stock engine, turbo, injectors, and intercooler. Also it has the stock exhaust from the cat back. Any help appreciated.

Thanks

 

[UNGN]

I would guess at least a couple mph and a few tenths.

 

[WarpSpeed]

Stock cat back,. you'd probably pickup 2-3 mph.
Get another 1 or 2mph more if you lock the convertor in 3rd.