below, pretty much answers it

should be like any long tube set up, and really help mid to upper rpm range power

Hmmm.

Want top end power, get the PPE's, want mid-low power, get FI's.

Our headers make good midrange and top end power gains. Our larger runners offer more flow, and we use a hand made merge collector with a choke/transition that brings up the midrange without loosing top end power gains. (Our new 2000 degree black ceramic coating also helps increase exhaust velocity too add a little more performance too)

Obviously I am a bit biased, but we have had several Pro race teams choose our headers including CWV-Rallysport, DWW Motorsports, and SFR Enterprises.

tbh i imagine both will make similar gains in the same areas (mid to high powerband), not saying fi's aren't great. i just am willing to say PPE's would make SLIGHTLY more because of their stepped design.

just my :twocents:

They really won't. The FI headers are great street parts, but their runners are too small to see large gains at the top of the rev range like the PPEs do.

I love F.I.'s exhaust, but the PPE headers are on a different level. The merge collector is a work of art. 15 degree angle, 5" smooth transition, they were tuned to a specific length to match the powerband of the motor, the black coating is just hawt. There is no bottom end loss, minimal gains, but the mid and top end lustworthy for an NA mod.

I refused to remove them when I wanted to go forced induction, so I spent more money to get something that fits around my PPE's ;)

Agreed with what's been said above. My low end gains were nice with the F.I.'s, but sacrifice top end numbers.

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.

FI LTH power curve: (ignoring the actual numbers because of dyno variance)



To one from my PPE's (sorry, chart is a little 'busy' hard to see the traces)

Thanks, much appreciated. I see the PPE's continued to climb while FI plateau at 7k rpm. I see PPE's file says Nismo CAI, was the FI dyno run with a CAI as well? I've read that CAI helps at the very top of the band. If the FI run did not have a CAI, could this be the reason why it plateaus compared to the PPE?

Most of the HP gains from either header mentioned here are from deleting the cats. Other than that you are losing some weight but the the power gains alone are not worth the install costs.

around $2450 including parts, labor, uprev license and tune vs resonated test pipes. Hard to justify the extra $ for the extra hp you get.

Another interesting dyno result
http://www.the370z.com/intake-exhaus...ers-35whp.html

The other car is equipped very similarly. Same exhaust, comparable intakes, etc.

The PPE's flattening out after 7300rpm is actually an intake manifold/throttle body restriction. (You can see the 'quenching' action this restriction has starting at ~6400rpm. A linear fall off of torque, that's what it looks like when you put a restrictor plate on an engine.)

I'll be addressing that eventually and then the top end will be even more dramatic.

Yeah the cost isn't worth it for a street car if you have to pay someone else to do it.

unless you do it yourself which is free :tup: