What are the major differences in the Piers unit and a stock HX-35?I am wanting to upgrade to a '35' but dont now which one to go with.I would prefer to get a Piers unit but dont know if I can afford it.A used HX-35 is a lot less$$$What are the performance variances of the two?Also,is the piers unit alot louder?Thanks guys

 

I think they have larger vanes giving it about a 12% increase in air flow compared to stock 35. Not sure though but it works just great on my truck.