i have a 2000 Si, and i want to get my shit ported and polished. how will it benefit me with hp, and will it lower my 1/4 mile time, if so by how much?

 

Well port & polish is not a big plus, but it does help w/ engines driveability. Improved A/F, gas Mileage etc.. it will add a couple extra ponies, if you plan to ever go turbo, do & mild port & polish don't waste any extra cash you don't have to. If you got the cash just upgrade the vavletrain while your at it. Pm me for some prices on vavletrain!

 

The most you'll see is 5HP, unless your running a lot of boost.

 

port and polish just makes the passages for air smoother. The less resistance that the air has, the faster it will go. If your going to consider doing things like port and polish, you midas well replace the valves with skinnier ones. That will help reduce resistance as well.
Just make sure not to port and polish too much or you'll make the walls too thin.

 

Unless you're running big boost or lumpy cams, a P&P isn't going to be a huge benefit.