I've owned my Dodge for over 4 years now, and have upgraded the lift pump, which is the raptor 100 gph on the side of the block, edge ez, 4 inch exhaust, and I believe it has at least 60hp injectors that were installed by the previous owner. I am at 400 rwhp now, tested at the hunting for horse power up in cda. My question that I am asking, why is my fuel pressure dropping down 5psi at WOT? I have spent many hours trying to find information on this, and its hard to get a definite answer. the Diesel mechanic I take my truck to says its normal, but I know its not, especially since my truck will start to stutter if I let off the pedal after stomping into it for to long( by no means do I drive the truck aggressive, I drive it like an old man, like my old man lol)  I want to upgrade my fuel lines to half inch from the tank to the lift pump, including fittings. but when I look online, I'm only finding the big line kit from the filter to the injection pump. Any advice would be much appreciated. I'm not looking to start a proper fuel psi forum, as I know its been beat to death.

 

15 psi at idle, 5 psi at WOT- doesn't seem normal. I'm on my second raptor 100gph -----this is my first post, let me know if I'm doing anything wrong.

Edited March 10, 20178 yr by Alexio Auditore

12 hours ago, Alexio Auditore said:

Are there anythings to be worried about going the mechanical way? How long have some of you been running mechanical? Any issues?

 4-5 years, on 25k miles. Downside is no extra filtration other than the stock fuel filter and will only work with oem harmonic damper, no aftermarket viscous damper.

The mechanical is sounding better and better lol. Is it a whole new serpantine belt or is it a small one that goes around, whatever it is it goes around, the harmonic balancer?

A new small pulley is installed to the front of the crankshaft pulley/ harmonic balancer and the pump attaches to the engine block via the front oil pan bolts.  This is where the belt adjustment is also.

 

Nice. That's 1/2 fuel line right? Does it come with half inch line to the tank or just to the stock filter?

Edited August 1, 20178 yr by Alexio Auditore
Fix sentence

This is what comes in a Fuel Boss installation kit.  The hose is 3/8 or up grade it to 1/2 and you can add a draw straw or use the stock pickup.  For my needs I stayed with the 3/8 hose and stock pickup.  If I was to opt for more power like bigger injectors and such then I'd install 1/2 line with a straw.

 

http://www.glacierdieselpower.com/product.aspx?pf_id=FB-98502

I'm seriously leaning to getting the mechanical. I can just get a replacement raptor under warranty ( since it will rarely be used) and then just do the mechanical pump.

I would've gone the same route but I chose the extra/better filtration. I'm sure you'd be happy with the mechanical pump.

A shop here in CDA I believe makes a separate unit for the filter and water separator, it's like what the fass looks like but without the pump, so that could be a option also, I'd have to double check just to be sure((( I could be totally wrong to, wouldn't surprise me))))

I kept the 3/8" line as well.  If I saw a drop in fuel pressure with acceleration I'd consider going to 1/2", but I don't have that issue.

I am cheap and do not spend more than needed. I installed a raptor 100 on the frame with a push on 3/8 screen (P550749) Vulcan. NO new drop tube.  Bought a tapped (tab) banjo for the pressure gauge which is manual and 3 push lok banjos (B1206) from Vulcan. I drilled all banjos out to size of the tapped banjo. Ran 3/8 hose clamp line all the way to the pump. The pressure gauge is a 30 psi oil filled mounted through the floor on the transmission hump fed by 1/4 in nylon tubing. This set up is a 294% improvement from stock. I set my pump to 18psi at idle. I have  13psi at full throttle on a 6% grade pulling 18,000 gvwc.  I change my fuel filter at 20,000. Spend more if you like, but this worked for me. PS , Stay away from QD fittings. QD's are not made for suction. 

8 hours ago, Hawkez said:

I kept the 3/8" line as well.  If I saw a drop in fuel pressure with acceleration I'd consider going to 1/2", but I don't have that issue.

What hp do you have?

14 hours ago, Alexio Auditore said:

What hp do you have?

Not much more than stock.

Near stock.RV275 injectors, no tuner