P7100 Lift pump fuel pressure

In the middle of my build. Building a street/strip truck for the time being, but eventually becoming a full time comp truck. Having the pump built for 5-550 cc, 5gsk, 5x20. The trucks a 1st gen, which I've engine swapped , and already has a Sump/1/2" lines. VE intended Fass is history, and I'm in need of a new lift pump. Seems to be alot of opinions on fuel pressure for the P7100. Airdogs 12v pump is present for 25-30 psi, Fass 45 psi, and yet people run 24v pumps with P7100 (15-18psi).

What is the recommended fuel pressure for these pumps?

And trying to decide is a 150gph is enough, or of a 220/240 is necessary for my goals

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my understanding is typically 10 psi per 1000rpms as a rule. We run street trucks between 50-60psi, and race truck runs about 70-80. I think 215 pumps require less psi than a 160.

I've run less in the past, like 25lbs full load and didn't see any difference jacking the pressure up. I know 160 pumps will benefit some with higher pressure but I didn't see any with my 215 pump.

Why not go mechanical?

There's a thread on CF by Dauntless89 regarding the hp the stock mechanical LP can support by streamlining the stock fuel system and removing all the banjo bolts. Pretty legit. I'm probably sitting around 500hp and my needle idles at 45 and never drops below that. And with a larger turbo, I can certainly put more horsetorques to the pavement. I'm anxious to see what this thing can do with compounds ..... but that will be a while.

Anyway ..... I'm in support of the mechanical LP.


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Stox5225 said:

There's a thread on CF by Dauntless89 regarding the hp the stock mechanical LP can support by streamlining the stock fuel system and removing all the banjo bolts. Pretty legit. I'm probably sitting around 500hp and my needle idles at 45 and never drops below that. And with a larger turbo, I can certainly put more horsetorques to the pavement. I'm anxious to see what this thing can do with compounds ..... but that will be a while.

Anyway ..... I'm in support of the mechanical LP.


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I've seen that and it's a pretty cool thread. You could also look a the one PDD sells. It's supposed to support up to ~750hp.

However, I believe the previous post was referencing a Waterman pump that can flow stupid amounts of fuel, but you have to run a billet timing cover with a hole for it and you need to modify your vacuum pump shaft to have an output for it.

Another option over the waterman is a belt drive automotive pump. I've been running one for 7yrs and it will make 50psi as soon as it cranks and ramps to 60 on a hard run feeding a 13mm. That's with the return regulator back almost all the way off, will make and hold much more I just haven't seen the need to.

Or Aeromotive makes some bad ass pumps. Lots of people run two A1000's to feed 13mm pumps. I know they have an A2000 and A3000 pump now too, but haven't seen any on trucks yet.

I'm running a modded mechanical lift pump following the outlined ideas in Dauntless' thread. 60psi on a 160 pump with racked barrels. Somewhere north of 600hp. PDDs pump is just a modded stock Cummins pump.

Bosch spec for a stock pump is 2 bar. I would recommend running at minimum 25-30 psi for a stock engine and I prefer to run a minimum of 45-50 psi on a 12mm performance build to ensure adequate fill.

Oh, and to answer the question of recommend FP for the P7100 .... anything 100psi and over you risk blowing seals and stuff. So I'd stick below that. I have mine set to 45ish with an Aeromotive X1 regulator with the 35-60 spring. Like I said, at WOT with 5x.012, 7mm DV's from PDD, and a 63/65/14 Super B, my FP never goes below that 45.


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