to run 15-20 psi, you will need the 550's. That is not a question. You will have problems controlling idle, especially if you are using an SAFC to control fuel. You may be able to do it with a rrfpr and an SAFC, but it would be difficult to tune correctly. Your best bet would be a stand alone or a piggy back that could do a better job controlling those, such as a greddy e-manage.

 

tim put be down for a set, u know im good for it hit me up laterz plz if u get a chance edit: also they high or low Impedance , they come with clips ???

 

hey tim.... that is great news..... that means, my kit will be coming soon... woooohoooo