[Joshinator99]

Originally Posted by JSH

What are the best PIDs to look at to determine how much room is left in your OEM high side with 30+?

Low side commanded/actual pressures
Rail commanded/actual pressures
Injector pulse width

Ted may have some more thoughts but that’s the TLDR version.

[JSH]

Originally Posted by Joshinator99

Low side commanded/actual pressures
Rail commanded/actual pressures
Injector pulse width

Ted may have some more thoughts but that’s the TLDR version.

Yes, but what are we looking for in those pressure differences, and IPW? For example is low side commanded 80 v. 75 actual a problem, or IPW >6 or <5, or?
I thought high-pressure fuel pump delivery duration was a key PID.

[Joshinator99]

Originally Posted by JSH

Yes, but what are we looking for in those pressure differences, and IPW? For example is low side commanded 80 v. 75 actual a problem, or IPW >6 or <5, or?
I thought high-pressure fuel pump delivery duration was a key PID.

You should be able to consistently hit commanded pressure on both low and high (rail) side. If you’re commanding 80 psi and it’s 75 the whole run, then that’s probably fine… but if it continues to drop then you could have an issue with the low side. I command 90 psi low side and it’s right around 90 the whole way down the track.

High pressure fuel pump pressure IS rail pressure…the HPFP is what charges the two fuel rails that feed your injectors. If that pressure drops off then your IPW will jump up… no bueno.

Keep your IPW under 6.0 in my opinion.

[KingLT1]

Originally Posted by radz28

Does anyone think this pump would work with a completely OEM tune (on the fueling side) and be able to run full E' on a bolt-on-only car with a low-side only? E.G. - with OEM injectors, OEM fuel pressure-settings-tune, and an aux'-pump for the low side? I'm talking from the perspective of being stealth, visually, and tune-wise. I want to run a Maggie 2650 tune with only this pump, as far as fueling for E' goes (and the aux' pump, which is in stealth mode already).

No you will run out of injector.

[KingLT1]

Originally Posted by JSH

Yes, but what are we looking for in those pressure differences, and IPW? For example is low side commanded 80 v. 75 actual a problem, or IPW >6 or <5, or?
I thought high-pressure fuel pump delivery duration was a key PID.

Low side 70+ psi

IPW <6.0ms

Rail pressure no more than 2-300psi lower than commanded.

HPFP delivery angle < 130 degrees

EOI >150

[JSH]

Originally Posted by Joshinator99

You should be able to consistently hit commanded pressure on both low and high (rail) side. If you’re commanding 80 psi and it’s 75 the whole run, then that’s probably fine… but if it continues to drop then you could have an issue with the low side. I command 90 psi low side and it’s right around 90 the whole way down the track.

High pressure fuel pump pressure IS rail pressure…the HPFP is what charges the two fuel rails that feed your injectors. If that pressure drops off then your IPW will jump up… no bueno.

Keep your IPW under 6.0 in my opinion.

I'm commanding 85 LS, which fluctuates between 77 and 83 at WOT w/meth.

[Joshinator99]

Originally Posted by JSH

I'm commanding 85 LS, which fluctuates between 77 and 83 at WOT w/meth.

Totally fine

[Megahurtz]

Originally Posted by KingLT1

Low side 70+ psi

IPW <6.0ms

Rail pressure no more than 2-300psi lower than commanded.

HPFP delivery angle < 130 degrees

EOI >150

This

[radz28]

Thanks for the feedback! Just trying to verify

[GAOLDGUY]

Originally Posted by JANNETTYRACING

The answer is no,

And, You would hit the low side limits and injector limits before ever hitting the stock high side pump limits.

No reason to upgrade the high side pump unless you are willing to upgrade the low side and injectors as well.

I thought this was an interesting exchange. I love the concept of your 580rwhp Streetbrawler package. What would you add to that package to get to full E?

[Megahurtz]

So far the ceiling seems to be ever so slightly higher than the LPE BB pump when on the stock LT4 cam lobe. I know the Goliath really shines with a cam but it will get you to E60 on a full bolt on, XDI 30's, X port and 2.3 upper setup. You can push past E60 but the rail pressure start to fall off. If you dropped the boost down it would probably support E80. I'm hitting 14.3 psi in 88F/2300 DA weather.

[RobZL1]

Originally Posted by Megahurtz

So far the ceiling seems to be ever so slightly higher than the LPE BB pump when on the stock LT4 cam lobe. I know the Goliath really shines with a cam but it will get you to E60 on a full bolt on, XDI 30's, X port and 2.3 upper setup. You can push past E60 but the rail pressure start to fall off. If you dropped the boost down it would probably support E80. I'm hitting 14.3 psi in 88F/2300 DA weather.

Great information. Thanks for being the test pilot, Jason.

[radz28]

Originally Posted by Megahurtz

So far the ceiling seems to be ever so slightly higher than the LPE BB pump when on the stock LT4 cam lobe. I know the Goliath really shines with a cam but it will get you to E60 on a full bolt on, XDI 30's, X port and 2.3 upper setup. You can push past E60 but the rail pressure start to fall off. If you dropped the boost down it would probably support E80. I'm hitting 14.3 psi in 88F/2300 DA weather.

How much power is this getting you? I understand E60 is, generally, about the highest alcohol content you'll get spark gains from, so it sounds like going up to E80 is just an exercise in finding the limits of the pump on the OEM LT4 cam, yes? Just curious for my own learning

Originally Posted by RobZL1

Great information. Thanks for being the test pilot, Jason.

THIS. Not that I would go to strictly DI, because of my situation, but if I ever decide that's something I need to do, it's good to have this information.

[KingLT1]

Originally Posted by radz28

How much power is this getting you? I understand E60 is, generally, about the highest alcohol content you'll get spark gains from, so it sounds like going up to E80 is just an exercise in finding the limits of the pump on the OEM LT4 cam, yes? Just curious for my own learning



THIS. Not that I would go to strictly DI, because of my situation, but if I ever decide that's something I need to do, it's good to have this information.

You can set the spark gain to whatever you want by adjusting the multiplier. On a STOCK LT4, typically you can get all of the timing the engine will make more power with on E50. On some wild setups you likely wouldn't want to do that, and you might only be able to give it all the timing it wants on E70+. Remember Ethanol content is essentially octane. Higher compression, cylinder pressure, and horsepower setups will want more octane.