I am running two fuel pumps with the stock fuel filter. something is restricting the fuel up top would it be the stock fuel filter?

 

I'm not even sure how much the stock fuel filter can handle, but I would say it wouldn't be 440hp...

 

I would say your maxing out the line size as well. Its aprox 5/16 i run 2 that size and have no problem.

 

I am thinking about running a single -8 feed and Y off two -6 feeds for both rails

 

I don't think the stock fuel filter is limiting you. Banzai racing is changing my fuel filter right now and is putting a stock replacement on. He knows I will pry end up at a little over 500rwhp.

 

..and make sure the rx7store was using a latop, the datalogit, and recalculating the base map rather than just using the commander before you go changing hardware. Chuck knows more about tuning the PFC than most people (I've used his documents).. he pinpointed one possible cause and you haven't updated us about whether or not that was it.

 

They used a lab top data logit software

 

...and hopefully they were using the 'recalc' base map.
To ask the obvious, did they replace the fuel filter?

 

well they have been tuning cars now for about six years I would hope they would know how to tune a car. I changed the filter about two months ago

 

This has NOTHING to do with a mechanical problem. It is PFC/datalogit related. There is NOTHING mechanical on the car that can prevent the injector duty cycle from raising if you are increasing injector on-time (adding fuel) in the PFC.

Closing this thread, the thread in the PFC forum is valid. https://www.rx7club.com/power-fc-forum-47/440hp-15psi-what-happen-fuel-system-654641/