Michigan Skip

suggestions? I' like one that mounts the same as the stocker, but also like it to be adjustable.

mdacton

iTrader: (3)

why do you need it?

Michigan Skip

Well, I'd like to be able to bump the pressure up a little more than what it is now.

mdacton

iTrader: (3)

is there a reason why?

I have heard of the problems with aeromotive ones that replace the stocker.

ss.slp.ls1

iTrader: (36)

Fuel pressure is computer controlled. No need for an adj fuel pressure regulator...
What do you think bumping up the fuel pressure is going to do for you?

RamAir95TA

iTrader: (2)

Correction...fuel pressure is vacuum controlled. Injector pulse-width is computer controlled.

Michigan Skip

I've heard of the trouble with the Aeromotive ones too.

ss.slp.ls1

iTrader: (36)

I meant to say fuel delivery is computer contolled...

shbox

Unless you have a 93 or are running speed density only or have larger injectors that need more pressure for proper delivery, the stock regulator is fine and there is absolutely no need to change the normal pressure. Unless for the exceptions above, changing the pressure will do nothing in the long run, as the computer will adjust fuel delivery based on O2 readings, essentially negating any changes you made. Maybe if you gave some more reasons or mod info to support what you want to do, folks could understand where you are going with this.

koolaid_kid

iTrader: (21)

I suggest that everyone go to the fueling section and go to the fuel injector calculator sticky. Punch in some numbers for our pressure of 43.5 (3 bar), then change the pressure to 58 psi (LS1 pressure, or 4 bar). Changing the pressure has the effect of rasing the effective size of the injectors. For example, a 36# injector at 3 bar is a 42# injector at 4 bar. No injector "needs" higher pressure, it is just that the numbers change when the pressure changes. This is how some vendors have artificially inflated their injectors sizes to LS1 owners.
There are more brands out than Aeromotive, btw, such as Accel or Jet. I use one that cuts off the top of a stock regulator and installs a new top with an adjusting screw. I got it from Hypertech.
You can also go to Frankens page and find a way to make your own from a stock regulator.

mdacton

iTrader: (3)

well I was going to say depending on your needs or why you want one I would do an external myself. they seem to be alot more accurate. I used to run high pressure on a stock injector b/c I was poor and cutting corners, I had to try something and it worked. Just welded some bungs on the end of the rails and had some -6 lines with an external. I had all the spare stuff on hand so I did it for free

DriftR

iTrader: (4)

So on my speed density 93 the only reason to change to an adjustable regulator would be internal engine mods that require larger injectors?

shbox

Knowledgable people can tune speed density with fuel pressure adjustments. The key point is they have to know what they are doing and be able to monitor it to make it work right.

96capricemgr

iTrader: (1)

The regulator should be used only as a fuel system component NOT as a tuning tool. It makes the same change across the whole operating range of the engine. When you modify and engine yes every operating point is probably going to need some tweaks but not exactly the same tweak, and that is all a regulator can deliver.

Just to be clear a regulator does NOT change fuel pressure but rather keeps it constant compared to manifold vacuum. We see this as a change because the gauges we use are referenced from atmospheric pressure.

Took me a long time to understand that, wish someone had explained it too me eariler on which is why I write it so often. I find it helps a LOT to understand the hows and whys.

skinnies

iTrader: (33)

I've been using the borg warner one from Oreilly's for about 2 years now without a problem and also have seen it on a few other local cars with great success. It works great up to around 70lbs of pressure, beyond that it will spike from 71-81 up to around 85-90lbs. I ran ~68lbs when I had my turbo setup because I was only running 42lbs injectors and couldn't find a good deal on a set of 60's and didn't want to buy new 60's only to run a few weeks at the end of the year.

Also with my cam only setup I'm running 58lbs of pressure so I can run the stock injectors right now in my rx7.

Michigan Skip

The reason I want an adjustable one is not so much to boost pressure in closed loop, I know the O2 sensors will comp for the added fuel, but to boost pressure in PE mode where the O2 sensors aren't used. I want to try to atomize the fuel a little more and see what that does. I am familiar with manipulating the fueling in PE mode and I use a wideband to verify my changes to the afr table.

I had low fuel pressure at the TB _39# with a cheap summit fuel gage. people told me it was the pump. I swapped out the stocker for a racetronix and it didn't help. New filter didn't help, so I'm going up the stream replacing stuff and the next is the reg. Probably woudn't hurt to get a good gage though.)

Thanks for the input guys, I know you're all just trying to help and I really do appreciate it.