I was looking at the FRx and HPx option that Riffraff has and was wounding if others that have installed them think its a worthy purchase. Also did you notice a difference in how your 7.3 idols, did it get quieter and any noticeable change in performance?

Just looking for reviews from those that have installed them and want to know more about the product.

Thanks in advance.

 

I've heard mixed reviews on the FRx, by itself.
But along with the HPx and new fuel spring at the bowl, and the FRx - is worth it.

 

Wonder why one would affect the other? One is for the Fuel side and the other is for the oil.

 

That's correct.
But keep in mind - your injectors are using the oil in the heads, pressurized via the HPOP, to push the fuel in when activated by the solenoid.
The HPx balances/equalizes the oil pressure - which helps the cackle a little bit because the more available pressurized oil at the injector.
So now that you're able to actuate the injector more efficiently - the fuel system could use a little help.
But because of the design between Ford and International (using Caterpillar style injectors) - led to the dead head issue,
where pressures were off. Hence why there is the long lead AE injector for the 99.5 through 03 7.3's in the number 8 cylinder.
While the rest (1 through 7) were AD injectors.
Once the HPx is installed, it's just lets you take advantage of the better fuel delivery when used with the Fuel Crossover (and/or with the upgraded fuel pressure spring at the fuel bowl.)

 

What fuel pressure spring is everyone using for the FRx?

55-60 psi silver spring
61-65 psi gold spring
66-72 psi black spring

 

I love the FRx. It cured my low speed on/off throttle feeling, smoothed the idle some and quieted down the idle and light throttle.

I passed on the HPx because there was no obvious or mentioned definite improvement. It just looks to me like more possible places for oil leaks or another thing to strand you on the side of the road if it cracks.

 

It varies depending on what your needs are.

This is true - my buddy had a leak on his. Hence why he kept his bolts in the glove box with a wrench for just in case.

 

My HPx has been on over a year and no sign of leaks or cracks. I have the plugs in the center console just in case. It did help the idle smooth out a bit, and that is according to my wife who asked me what I did to the truck after I installed it. The FRx with the Hutch mod has my truck idling even quieter after installing it last week.

 

What did the low speed on/off feel like? I think I might have the same issue, thought it might be the gas pedal going bad. Its almost like you take your foot off the gas really quick. Then it comes right back at slow acceleration and parking lot cursing.

It sounds like it definitely makes a difference at smoothing out the idol. I thought more people would chime in as I see this mod in a lot of signatures.

 

That was exactly it. Parking lot speed it is very hard to get a nice spot in the peddle to just "cruise". It was either a "throttle on" where it was a little to much but if you let off the peddle just ever so slightly it would instantly return to idle speed. The FRx totally fixed this for me and I can now keep a constant slow speed threw a parking lot.

 

Well that just sold me on it! I was getting ready to buy a new adj. pedal for $550. So I will try the FRx and see what happens. Might as well just buy the HPx to I guess and keep the plugs like the others are doing also. I'll talk with Clay about it to and see what he says about just getting the FRx.

 

You'll be happy with it!