Some NEWB E85 Questions

Sounds like you're relief valve is failing. Hpfp active pressure should remain 1600+ under load.

 

Glad you're enjoying the ethanol also the "Cobb" set of hpfp internals = autotech. Options really are autotech or corksport with them being similar enough. I know Raider had his autotechs fail and swapped to CS.
Definitely worth testing your PRV

 

I replaced my PRV less than 10k miles ago with a new Mazda factory part. Just ran out and ran the test again. it went to 1835 before it popped off but it took F O R E V E R to get there. Like 20 mins. When I ran the test last time, I thought I remembered it taking less than 5 mins.

I understand why we run this test and why it is valid, but I do not understand how it works. I don't understand how pressure climbs without the cam turning and pumping the HPFP. Is it purely the fuel heating up in the rail?

 

Yes. That's why having a hot engine is important for the test.