Fuel Pressure Question...

[Infidel Edition]

So like most things.... I read a couple threads and got excited and searched for, found, and ordered ~ XYZ

For example, Durango soft line for rear brakes and C1500 front...
Another ~ Neon fuel injectors.

After installing them, someone had told me that Neon injectors "work" but are "a waist of money" because they're designed to run at 40+ psi.
I noticed a smoother ride with them. But that also could be the 30 old stock injectors were crap.

I came across a thread for an adjustable fuel pressure regulator (like $300) so I could increase the pressure to 40-45 psi.
....but dropping $300 is more than I want to do if they currently run fine.

Then I came across a thread for fuel pressure regulators that are direct swaps. AND to get to the NEON's target of 40+, I could just find a 90'ish (I think 90/91) Caravan, it's a direct swap.
So before I go junkyard hunting, I like to check RockAuto to see what their prices are, because why drop $20 for used when I could get new for $25-$30...

I ordered 1 and should receive it in a couple days. Install it when I swap the NEON injectors from my '89.
And then I started to wonder. I haven't read on the logic of increasing fuel pressure.

SO HERE IS MY QUESTION.... Since I can't adjust my OBD1 computer
Is bumping my PSI to 40 going to cause me to run real rich?
Or (what I'm hoping), will it make the NEON Injectors do their magic and better atomize my fuel?

[4.3LXJ]

That is a good question. The Jeep ECM is really kind of stupid. It learns slow and is not very flexible, as in strokers. People in CA have trouble with making strokers pass smog. That being said, if they are designed to work at 40 psi, then go for it. The whole idea is better atomization and that is pressure related. When you do, clear the computer memory and start that from scratch

[Infidel Edition]

I guess the worst case is I'll idle REALLY HIGH.... and end up putting the stock FPR back.

...was digging around and found the Head I'd like to pick up
http://www.shop.505performance.com/product.sc?productId=310&categoryId=46

To get the stock rebuilt (not ported) + valves, guides, springs, rockers... set me back around $400 ~ to get it ported was quoted as another $100. And to grind out the valves to go 2.00/1.570 ... $????
...........AND it would still be the stock cast with the associated potential issues.

This one is spendy, but ported with the LS1 valves 2.00 intake / 1.570 exhaust.
It's a heavy cast for durability
They claim it's a 30 hp gain without the other mods I'm doing.

[4.3LXJ]

If you are going to drop big bucks, I think Edlebrock has one designed from the ground up that gives bigger gains

[Infidel Edition]

From what I've seen, Edlebrock has a cool 4.0 head that is performance designed and 1/2 the weight.
But it's twice the price and not a complete head.
Do I'd still have to pick up the valves, springs, rockers, etc.
Or at least that's what it reads like.

[Infidel Edition]

It was driving me nuts because I knew I had come across a better reference for the fuel injectors.
And I was mistaken (as were the people that pointed out the lower flow)..
The Neon injectors are roughly the same (but with better atomization) as the stock injectors.
But with the Bosch 710's and the Chrysler FPR, it's a slightly higher flow AND better atomization.
Stock is roughly 19 lbs at stock psi.
The 710's (Ford) are 18.1 or 18.2 lbs at the stock XJ psi.
And should be 19.+ lbs with the extra psi.

Here's the Fuel Injector flow ref:

9349

[Infidel Edition]

...before my laptop decided to update and reboot....I had found a site that referenced the Lbs/hr at PSI for both the stock and the Ford...
And I came across a site that did HP to Lbs/hr x psi.

In a perfect vacuum, this is roughly what I found
....Stock is like 18.8/Hr at 38.5 psi
........ Ford 710's are 19/Hr with the Chrysler FPR bumping 5 psi (should be closer to 10):

Stock
9350

With Ford inj. + Chrysler FPR

9351

Yeah, I know those are perfect world and assuming the intake and exhaust can take advantage of ....
But you get the idea.
~ so all other things being equal, 1 LB/HR and 1 psi should gain roughly 5% or 10 HP

[Infidel Edition]

And for good measure, a friend provided additional insight.

The potential HP gain associated with upgrading this / or that / or the other thing is deponent on the ability of the remaining components to keep up.

Thus, the potential HP gain from going to higher flowing injectors AND higher pressure on the regulator is dependent on the air flow of the system to more of an extent than the other way around.
~ Potential increases from better air flow are less dependent on fuel injectors until you start getting in to big mod's
Like a stroker would want a 24# injector with the increased fuel regulator to feed it.