I was wondering If there is a way to swap FPR on my Radix? My Flex Fuel engine FPR holds the pressure back to 50psi at idle and lets it spike to 62 at WOT. I was wanting to swap to a FPR that allows me to idle at 60 or so and then spike up to ??psi at WOT. Can I just do a swap with what normal trucks (non Flex Fuel) use or do I need a special one?
Thanks

 

I'm looking to go with a Aeromotive regulator with an adjustable base pressure vacuum indexed to add one psi fuel pressure for each psi of boost.I don't know if your system is different than mine,but I will fill you in on the details of the change in a couple of weeks.

 

When you say 1 psi for each psi of boost, does this account for the vacuum? So, if I normally sit a 18psi vac and then hit the gas and go to 0 boost/vac am I going to get +18psi of fuel pressure? OR does it only kick in after you get into actual boost so at 7psi I get 7psi more fuel pressure? That doesn't seem like much.

 

The reason you see a much lower FP when idling is becasue there isnt as much air to be fueled flowing into the engine, when the throttle is opened and vacuum drops the FP will rise because there is actually more air now.
This is how ALL vacuum reference FPR's work, even stock units.

Now the Aeromotive does EXACTLY the same thing as the stocker EXCEPT that in addition to normal NA FPR duties, when it senses boost, it will continue to add an ADDITIONAL 1 psi of FP for every pound of boost it sees.

You dont want a FPR that will sit at 60 spi at idle because the injectors will be injecting TOO much fuel, the idle mixture would be rich. But the Aeromotive has an adjustable base pressure so you could dial it to wahtever you want.

I beleive what you need is a vacuum referenced ADJUSTABLE fuel pressure regulator, like the 1 that whitt1 is talking about.

The AFPR that whitt1 is talking about is on a 1:1 ratio, so if it sensed 10 lbs of boost, it would raise the FP by 10 psi.

Aeromotive makes some very cool stuff, it is expensive but they make products that can fuel several thousand hp.
email Aeromotive, they will send you a free catalogue, they sent 1 up here to Canada for me.
peace
Hog

 

I am willing to get the truck tuned for the increased rail pressure. I am thinking along these lines, tell me if I'm off:

Higher rail pressure means I get more out of my injectors HP wise.
Higher pressure should mean more volume of fuel so I don't run lean as soon on top (if at all). I know volume and pressure are two different things but with my inline fuel pump I figured it should be able to keep the volume up with an increase in rail pressure. I was thinking switching to a standard FPR like most NBS trucks use would get me to 60psi at idle and 64 or so at WOT. Right now I sit @ 50 at idle and only get to 62 @ WOT and if I'm going to up the boost, I want more than enough fuel flow. I've read on here of guys with rail in the 70-80psi range. That's why they get crazy HP numbers on stock injectors.
Let me have it.....

 

You are on the right track with your reasoning but your methods are off. If you are currently seeing 52@idle and 60@wot, you are seeing the same pressure as a stock reg fuel truck(assuming the stock regulator is reused with the radix). If you do have the same reg as us, it is slightly adjustable using a small security torx bit so you may look at it and try turning it up to get the pressure you desire. If that dosnt work, you may want to take hog's suggestion and try and aftermarket adjustale vacume referenced regulator.