2010 Camaro LS3 Injector Delta Pressure?

[scv_guy]

There's a mechanical regulator in the fuel pump assembly within the tank. You're going to be clipped at 58psi rail pressure if this is a LS3 Camaro. In boost, it's automatically going to drop delta pressure.



You cannot tune away a mechanical limitation.

I installed a Livernois dual pump assembly, I'm not sure if there are any setting or tables that need to be change to make the pump work properly. Per Livernois the pump will support 800rwhp I'm nowhere near that.
I am seeing the fuel pressure drop while logging and at the rail with a mech gauge. this is a 2010 L99 Camaro SS with a turbo
at 7psi the fuel pressure at the rail droops from 58 to 50 psi.

[DSteck]

Yea... That thing supports nowhere near 800whp. If I remember right, it's just a CTS-V pump assembly with factory CTS-V FPCM.

[scv_guy]

Yea... That thing supports nowhere near 800whp. If I remember right, it's just a CTS-V pump assembly with factory CTS-V FPCM.

They are claiming you need to adjust the drivers however they will not be specific on what needs to be done. They said it was a drop in replacement, using the factory Camaro FPCM

[10_SS]

Here's a screenshot of my fuel pressure drop under boost (im the OP).. is this similar to yours scv_guy?

now would also be a good time for someone to explain the Manifold Vacuum Patch if you could please... I'm the OP, and I also have been dropping rail pressure since 2012 when I installed this setup.. (stock 10 LS3 pump with MSD BAP)...

Example... without patch.. 49kpa load, 58psi rail, 65.6psi Delta... at above 100kpa, the two values display as equal, and at 151kpa MAP, fuel pressure falls to 45psi (both read 45psi), but in reality delta pressure is lower, at ~35psi right (though both are reporting 45psi)? These psi readings are from the stock location... by the tank.. not real rail pressures.

How would the patch change this situation? I would not want to apply the patch right now, since it will alter my MAF/VE tables im sure... correct?

WOT_FuelPressure.PNG

[scv_guy]

Yep that's what I'm looking at also, but I'm running the Livernois dual pump. I didn't think I would have this problem. The guys at Livernois said I had to adjust the pump drivers?? but where not where specific...

[schpenxel]

Here's a screenshot of my fuel pressure drop under boost (im the OP).. is this similar to yours scv_guy?

now would also be a good time for someone to explain the Manifold Vacuum Patch if you could please... I'm the OP, and I also have been dropping rail pressure since 2012 when I installed this setup.. (stock 10 LS3 pump with MSD BAP)...

Example... without patch.. 49kpa load, 58psi rail, 65.6psi Delta... at above 100kpa, the two values display as equal, and at 151kpa MAP, fuel pressure falls to 45psi (both read 45psi), but in reality delta pressure is lower, at ~35psi right (though both are reporting 45psi)? These psi readings are from the stock location... by the tank.. not real rail pressures.

How would the patch change this situation? I would not want to apply the patch right now, since it will alter my MAF/VE tables im sure... correct?

WOT_FuelPressure.PNG

What's happening at the rails?

If the fuel pressure is literally going down at the rails during WOT (forget about effective pressure vs manifold pressure, etc.) then it doesn't sound like you have enough fuel pump or it's not configured properly if there's a way to adjust it's output (not familiar with that setup)

Is that what is happening?

[scv_guy]

What's happening at the rails?

If the fuel pressure is literally going down at the rails during WOT (forget about effective pressure vs manifold pressure, etc.) then it doesn't sound like you have enough fuel pump or it's not configured properly if there's a way to adjust it's output (not familiar with that setup)

Is that what is happening?

Yes I'm seeing the drop at the rail. According to Livernois there are adjustments needed in the tune (what tables is the question) they didn't say! With this pump at my power level (590ish) this pump should be more then enough.

[schpenxel]

Yes I'm seeing the drop at the rail. According to Livernois there are adjustments needed in the tune (what tables is the question) they didn't say! With this pump at my power level (590ish) this pump should be more then enough.

Have you tried increasing the MAF values at the areas you're going lean?

[scv_guy]

Have you tried increasing the MAF values at the areas you're going lean?

No I have not, I was hopping to correct the fuel pressure drop at the rail before playing with the tune.
Is there a voltage table for the pump/FPCM im not aware of?

[schpenxel]

No I have not, I was hopping to correct the fuel pressure drop at the rail before playing with the tune.
Is there a voltage table for the pump/FPCM im not aware of?

I've never seen or heard of one, but that doesn't mean there isn't on that car

I know there isn't on mine, but I am not very familiar with the Camaro platform, so hopefully someone else can give you a solid answer.

[scv_guy]

Any help would be great!

[Jeffrey110]

This is perfect timing for me, I am currently going through something similar.


I was reading, and I am aware that everything I read is not always true, hard to believe, but anyway. I was reading that to get your pressure or to at least determine if your good on FP, that you take your injector delta pressure and add your boost number. So if my injector delta pressure is at say 47 and my boost is 14, then that would effectively give me 61psi, which would mean I'm good and not running out of fuel.....Is this true?

Can anybody shed some light on this subject for me?

My issue is that I'm currently at 747whp on TT's, I have Livernois dual pumps, and an ECS BAP. When I installed the BAP I installed it because my SAE FP and Injector delta pressure were in the mid 40's at WOT. I have hardly noticed a change and want my FP above 55psi. I am under the impression that that 40amp ECS BAP is not enough and am thinking that I need to go to a MSD 2351 programmable BAP to get to where I need.

How accurate is the FP reading out of the E38 PCM?
I understand that the pressure sensor is near the tank, do I just need to go to a stand alone gauge and measure it at the fuel rail?

Any help would be greatly appreciated.


And to answer a question the only way to alter the Fuel pressure control module that I know of is to send it off to ADM, at least for the E38's you cannot change the values to make any difference on your own. I also was told that it was a drop in direct replacement and no other things were needed.

2012 Camaro LS3 Alky Control Dual meth nozzle

Camaro ECS BAP.hpl

[schpenxel]

I was reading, and I am aware that everything I read is not always true, hard to believe, but anyway. I was reading that to get your pressure or to at least determine if your good on FP, that you take your injector delta pressure and add your boost number. So if my injector delta pressure is at say 47 and my boost is 14, then that would effectively give me 61psi, which would mean I'm good and not running out of fuel.....Is this true?

While in VACUUM you can add your vacuum # to the fuel pressure to get your effective fuel pressure. 8 psi vacuum, 58 psi fuel pressure = 66 psi effective fuel pressure

However, in boost it's the opposite. 8 psi of boost, 58 psi of fuel pressure = 50 psi effective fuel pressure

Think about it... you're basically pressurizing the intake. That means there is air pushing on the injectors and fuel just the same as it's pushing on everything else.

The example I always do in my head is if you ran 50 psi of boost and had 50 psi of fuel pressure, what would happen? The answer is the same thing if you had 0 psi of fuel pressure and 0 psi of boost. Your effective fuel pressure would be 0

While in vacuum you're basically sucking fuel out of the injectors, increasing the effective fuel pressure

While in boost you're pushing back on it, decreasing the effective fuel pressure

(I've never worked with a car that had a factory fuel pressure sensor, so I can only guess that they read the same as every other fuel pressure sensor out there, but if not, someone please correct me)

[Jeffrey110]

I know AFR is not the proper way to judge your fuel supply but if that's the case then I'm at 32psi, and still fat in my tune in some spots. Damn this is getting worse not better LOL

I guess I figured with an 40 amp BAP, Livernois dual pumps, and dual nozzle meth, I should really not have these issues. Is there anything I need to change in my tune to accommodate the dual pump setup? Everything I have read say that their pumps are direct drop in replacements.

[schpenxel]

I know AFR is not the proper way to judge your fuel supply but if that's the case then I'm at 32psi, and still fat in my tune in some spots. Damn this is getting worse not better LOL

I guess I figured with an 40 amp BAP, Livernois dual pumps, and dual nozzle meth, I should really not have these issues. Is there anything I need to change in my tune to accommodate the dual pump setup? Everything I have read say that their pumps are direct drop in replacements.

To me, bottom line is if you can get enough fuel in to match the ratio of air you're getting, I don't really see why the problem

If it's still rich then I don't really see how it's a problem...?

Are you running a boost referenced regulator or what?

[Jeffrey110]

To me, bottom line is if you can get enough fuel in to match the ratio of air you're getting, I don't really see why the problem

If it's still rich then I don't really see how it's a problem...?

Are you running a boost referenced regulator or what?

I would tend to agree, plus my IDC no more than 65. I guess the problem is that I have always been taught that if your shooting for 58psi then you really shouldn't deviate from that more than a few psi. Most people that I have talked to or read about, like FP for 2010+ Camaros to be no less than 50psi. The Camaro's run a returnless fuel system and they do not run a boost referenced regulator.

Thank you for your help, I greatly appreciate it.

[schpenxel]

I would tend to agree, plus my IDC no more than 65. I guess the problem is that I have always been taught that if your shooting for 58psi then you really shouldn't deviate from that more than a few psi. Most people that I have talked to or read about, like FP for 2010+ Camaros to be no less than 50psi. The Camaro's run a returnless fuel system and they do not run a boost referenced regulator.

Thank you for your help, I greatly appreciate it.

Yeah I knew they ran that type of setup stock but thought might have had some sort of aftermarket fuel system.

Bottom line if it's working then I don't see the problem

[Jeffrey110]

Only aftermarket system, is the drop in dual Livernois pumps, which I believe are just CTS-V pumps, plus a 40 AMp BAP. The BAP was just installed recently and from what I can tell does absolutely nothing to help my pressure. At first I thought the BAP wasn't functioning properly, after three or four phone calls with ECS I literally put my brother in the back seat with a voltage meter and had him read me the volts as I went into boost....poor guy....Anyway It makes no sense to me. I even called Livernois today, they are drawling a blank too. According to them, there is nothing within the PCM that I can adjust to make any noticeable difference and they also say with my current fuel setup, I should be good to at least 850whp. The only thing I haven't mentioned is that I am also cammed.

The thing that scares me about the whole, "if your AFR is good then so are you" thing is another one of our hpt forum regulars who drives a 5th gen camaro also had the same or close to the same FP as I do and just recently lost his engine. From what I gather, it was fuel pressure related, and his AFR was good too. Although I don't believe he was running 14psi I think it was more like 10.


Think next year its Fore triple pump time....