Ok, so I've been researching about velocity stacks. I have heard GREAT things about BPI, and a lil' about Prototype. But I was wondering if there is really that big of a difference between brands. For example Turbonetics sell some too, are they any good? I mean aren't they all just about the same? Am I really going to be able to notice a difference bewteen one form another?

Any input would be great.

 

The BPI ones have proven to have good gains, im not too sure about the Phototype ones or the turbonectics one.