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LSX454 swapped 95 BASS burb.

Little lower, little cooler, bigger sounds.
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I have a tbss intake, with gm rails. I added an inline pressure sensor at the rail. I’m also running the regulator Heath is mentioning.

Zero fueling issues and mine is overkill for my cammed 6.0
 
The npt vs AN connection thing doesn't bother me.
Not too worried about billet either lol.
In a part like that, it's only really a looks thing.

Does the vacuum reference help in a way? Less fuel heating or something?

Looking at it it seems like it would let more flow go by under vacuum. Like heavy vac would allow more return, and less pump fighting spring action.
Then boost would add pressure to the spring, increasing pressure some for high RPM feeding..

Is that right?
 
The idea behind vacuum reference is you end up with more resolution from the injectors. The difference in pressure across the injector is kind of constant, so spray pattern and the length of pulsewidth to deliver a certain amount of fuel are kind of constant. With fixed pressure, the ECM just has to compensate more for the changing pressure, either by monitoring it, or that being baked into the fuel map. One way of looking at it is that your injectors don't have a fixed "lbs/hr" rate, but it varies with both rail and manifold pressure.

Most EFI cars were vacuum referenced in the 90's and 2000's, including LS engines, until they went returnless around 2004.
 
@Blue85 is correct, it equalizes the pressure delta between the injector fuel rail and the intake manifold side. So at low load, (high vacuum), it reduces the pressure for better resolution.

On the flip side, for boost, it increases the pressure for more flow potential.

The billet model with the o-ring is less likely to leak. I don't like NPT threads with gasoline at 60 psi. However, if you use some gasoila, it should seal up fine and save you some dough.
 
The vac reference one, wouldn't affect the tune, since it's already reading the MAP in the Terminator X, and probably adjusting for it internally?

If that's the way I should go, then I probably will. Just making sure I don't have to change anything in the ecm.
 
The ECU will compensate again, target AFR is still the same and the change is not that big. If you want you can try it first without a vacuum reference hose hooked up, then hook it up after.
 
Would it be ok on the frame below the driver's seat with 3'-3.5' of -6AN running up to the rail?
If so all I'd have to do is land it where my current one is and figure out the return line connection.

Looks like it'd be a pretty simple install that way.

It'd be over a foot away from my exhaust like the current one. So no worries there.
 
I think with vacuum reference a shorter vacuum line is better for response.
 
After you said that, I remembered that I'm using the internal MAP sensor that's inside the Terminator X unit still. With about 3' of hose.
I have an actual sensor in my intake, I just never turned it on in the ecm.
 
I played around with the TB again, with a different camera angle.
Looks like it does stop at 90.
Looking at it from the front, and the angle of the body gave me an optical illusion.
This view show positive stop, and my pedal.
The difference is miniscule and would equate to about 3 HP or so, maybe.
But I can see how it would allow the wot to waver a percent or 2 when holding it down.
Only way I can fix it, is extend the arm on my pedal assembly to get more arc.

I have an idea how to do that easy enough. Just gotta get it done.
At the same time, I'm still going to space the assembly out a touch to keep it out of the carpet, and remove the pad behind the carpet in that general area.

Screenshot_20240501-120806~2.png

Screenshot_20240501-120752~2.png
 
shady said:
Looks like the stock L92 rails don't have the pressure port either..:dunno:

Notice the mounting tabs.

On the TBSS intake, they're inside the rails

View attachment 474008

View attachment 474009
Click to expand...
That's so weird. Now I remember an issue I had with a leak on the original fuel rail from the TBSS intake I'm running. I bought a replacement for a gen IV truck and it's mounting tabs were different so I had to return it and buy the TBSS specific one. The original TBSS one had a test port, while the new AC Delco one did not. The original rail here:

PXL_20210604_020132983.jpg


But it wasn't a big deal since my regulator has a fuel pressure gauge on it. Since I'm running a stock ECU, it expects a constant pressure so I never hooked up the vacuum line

PXL_20230627_040109796.jpg
 
Could this 75 psi thing have anything to do with having a 3/8 feed, and 5/16 return?
 
shady said:
Could this 75 psi thing have anything to do with having a 3/8 feed, and 5/16 return?
Click to expand...
Are you running a stock fuel pump? If so on paper it should work, but the design of the Corvette reg might be set up for a 3/8 return if that's what it had in it's original application. If you think it's restricted, take the return line off, and drop a temp 3/8 line into a gas can right below it and cycle the fuel pump. If the pressure drops to the designed 58psi, then it's a return line issue. If not then it's a regulator issue.
 
:thinking:
Now that you bring up the pump, I gotta go through and see what one I have.

I know it's a lingenfelter, but I don't remember if it's the 50gph, or 67.... I may not have enough pump for the new parts going in.
 
shady said:
Could this 75 psi thing have anything to do with having a 3/8 feed, and 5/16 return?
Click to expand...
That setup is fine for what you are doing.

The return line on EFI setups can be a size smaller usually.

Now if you are trying to drop the fuel pressure back to carb pressures with a high flow EFI pump, I recommend the return line be the same size, or it can become the restriction.
 
I know I bought my pump at summit.
But unfortunately summit doesn't show orders from that far back.
So last night I went all through the motor thread I started for the LS build, then onto this thread.
I can find mention of what I would want in a pump. And I can find where the tank is already going in.
But I can't find what pump I used anywhere.:dunno:

So I went to summit to look up the lingenfelters.

They only have the 2 I would have chosen from.

The pic I see in my head when I think about it, is the 50gph.

But I remember having a conversation with someone. May have been Beags (Brian) , and we were saying the one I got should be good to 700 HP.
So now I have absolutely no idea lol.

May end up buying another one and dropping the tank, just to KNOW what I have :doah:
 
Something came to mind.

Will a pump that claims 60 psi from the manufacturer, run 75 psi even?

The 2 lingenfelters at summit are a 60 psi 50 gph/190lph.
And a 90 psi 67/255.
 
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