they are but i think that you would get better performance with the money spent else where they run about $250 and arent really needed until a bigger turbo is in. But you might get a little more performance with it i would rather buy a downpipe that is more power and a better investment

 

I would steer away from this unless you have modded the exhaust components first, because this is a tiny mod and $250 spent on a downpipe would be a LOT more noticeable than the inlet hose,

I have a Perrin Inlet Hose, increased my spool time by a couple hundred rpm, but I have a wrx not an STi, good mod if you have done everything else and are looking for something new to add under the hood

 

definitely go with the Samco one. I've got a Samco one ready to install with my SR/50 and supporting mods. when i brought it to LIC, they compared it to the Perrin one, and the quality is much better on the Samco. All the hookups for the hoses etc. are in the same place as the stock piece on the Samco, where as the Perrin ones are all located in 1 place, instead of their stock locations.