Installing an frx and hpx soon have ?

Worktruck00' · Jan 12, 2015

First off new to the form and all info is appreciated! As title states I'm going to be installing a frx and hpx from riffraff soon my main question is what are the pros and cons of the higher and lower springs in the frx kit I know they regulate fuel pressure but why wouldn't you want to use the spring that creates the most fuel pressure I'm sure there is a great reason why im just curious and wanting to know more before installing?

Arisley · Jan 13, 2015

The 7.3 likes between 60 and 65 PSI. More than that is not good on a stock truck. Mine runs best with 62PSI. That's with 250\200 injectors.

Justin@DP-Tuner · Jan 13, 2015

Use the middle spring. I too, have found that my truck likes 62psi the best.

DEEZUZ · Jan 13, 2015

the higher the pressure the more strain on the injector seals. There is no need for anything above the middle spring.

I also run the middle spring and have this same kit. truck loves it and with a good pump, the fuel pressure should not vary much even under WOT.

ghohouston · Jan 13, 2015

Same here installed the middle spring on my obs

Magnum PD · Jan 13, 2015

Tell us about the truck and Welcome!

stock73 · Jan 13, 2015

I've read about the hprx and the frx , really interested on how it goes

Keep calm and Stand on it !! Sent from my iPhone using Tapatalk

Justin@DP-Tuner · Jan 14, 2015

stock73 said:
I've read about the hprx and the frx , really interested on how it goes

Keep calm and Stand on it !! Sent from my iPhone using Tapatalk

It's a great kit/upgrade for the price. There is really no replacement for a full regulated return kit, but for stock to minor injector upgrades, the FRx works very well.

stock73 · Jan 14, 2015

Thank you Justin , is there any manufacturers that are better than others?

Keep calm and Stand on it !! Sent from my iPhone using Tapatalk

five0merc · Jan 15, 2015

That's good to hear that those are good products. Was planning on ordering those myself for the truck I just picked up. On the to do list for sure now.

Justin@DP-Tuner · Jan 15, 2015

stock73 said:
Thank you Justin , is there any manufacturers that are better than others?

Keep calm and Stand on it !! Sent from my iPhone using Tapatalk

Riffraff is the only one who manufacturers the FRX. We carry it though. Check it out HERE.

Strictly Diesel's is the best full regulated return kit in my opinion. We carry it as well. Check it out HERE.

lariat 7.3 · Jan 15, 2015

i ran one for 2 years, just recently pulled it off to do a full RR. Every time i swapped injectors it always fired up within ten seconds. I think do to the frx allowing fuel to circulate the heads before i would crank

DEEZUZ · Jan 17, 2015

yep. with filter changes, injector swaps, etc, there is no longer a need for cycling the pump, just key on, wait a few seconds and GO!

It truely gives you an idea of how well of a design flaw this was from the factory, to dead head and airete injectors... blasphemy!

Worktruck00' · Jan 21, 2015

Installed the hpx last night truck is much smoother at idle quited the single shots down a lot
Took literally 20 min to do, just had to take intake out, installed the frx tonight went pretty good little over an hour but forgot to re instal the plunger into bowl first time around oops&#55357;&#56833;
Over all both great products from the initial test drives and starts much faster now good feature at -10 here in MN

Worktruck00' · Jan 21, 2015

Drove truck to and from work today and noticed at WOT it makes a high pitched chirping noise coming from driver side of motor is this what it's supposed to sound like now with the frx or is this any issue air/fuel leak? Truck didn't do it before frx, injectors are only a few months old if it matters?

Black 02 · Jan 21, 2015

I added an FRX to my truck a couple years ago and it made zero difference in the noise.

Justin@DP-Tuner · Jan 21, 2015

Worktruck00' said:
Drove truck to and from work today and noticed at WOT it makes a high pitched chirping noise coming from driver side of motor is this what it's supposed to sound like now with the frx or is this any issue air/fuel leak? Truck didn't do it before frx, injectors are only a few months old if it matters?

Sounds like turbo surge. Can you video/record it to confirm?

Are you just using the stock turbo with WW2? No ported compressor housing?