Originally Posted by nismomo

Can someone post dyno sheets? I'd like to compare curve patterns, I saw a PPE sheet with similar flattening at the top. I also read mixed articles on the benefits (or lack of) stepping. Both companies provided different info. Having said that, there is a local shop that works on many Zs. They've installed both FI and PPE and they are saying PPE are delivering better gains. This thread has not helped me pick one over the other. FI has a great reputation and I think Tony would be interested in evolving his header design if he thought they could be better. People above my post are making claims about collectors, materials, etc... Are these just opinions? Let the charts tell the story.