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Mind if I do a J?
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We did a little over 700whp on one single pump and E85 but with a single -8 feed line.
 

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We did a little over 700whp on one single pump and E85 but with a single -8 feed line.
Do you think this was near max power you can make with the one pump? I'd like to buy a larger in tank pump instead of trying to get two 450 pumps in my MKIII. I don't think I can find one in tank pump capable of 800 rwhp on e85. Thanks.
 

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Has anyone maxed out a single walbro 525/Hellcat pump on e85? If so, were you on the factory feed line?
I've been warned by my tuner/builder to not use the hellcat pump as the primary pump. Apparently it generates much more heat than the 485/455 E85 Walbro, which can cause cavitation in the pump.

I use a 485 as my primary and 525 and secondary. The secondary turns on after 15psi.
 

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Racing is Life.
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I was able to achieve 705whp on a single Hellcat pump. I have a fuel pressure sensor and the pressure baseline I run is 40psi. In 30psi of boost theoretically if the pump is properly sized I should see approximately 70psi of fuel pressure. Unfortunately as the boost comes on it begins trailing off at around 20psi and at 22psi or so it starts falling. At 30psi I'm in the 40psi of fuel pressure range. The issue is differential pressure. It just can't keep up with the fuel requested beyond approximately 20psi, or 600whp at 0.80 lambda target.

My ECU calculates fuel using VE and injector pressure. So it takes the boost pressure and fuel pressure and determines the difference and that's the injector ∆PSI. That is what all of the charts are used for on my ECU. So it isn't charted below 30psi of injector pressure. When I'm at 30psi I'm seeing 40-45psi of fuel pressure with the single Hellcat pump at 0.80 lambda. Simple math and I'm only at 20-25psi of injector pressure, so the ECU runs out of data to determine fuel injected, not to mention sketchy things will happen if I turn it up more even if the fuel pressure doesn't drop anu more - because eventually I'll have more air pressure than fuel pressure.

IMHO 600whp on E85 at 0.80 lambda is a safe conservative single Hellcat 525 limit. "Running the ragged edge" limit I'd say is pretty much where I'm at and that's 705whp/[email protected] At 705whp I'm seeing 65% duty on my injectors which are effectively ID2000. So there's a data point for you I suppose. At 0.78 lambda the pressure falls off even more.

I have a Radium hanger just chilling and all the lines and everything to do the job but my lift is being taken up by the race car's project. Once it's done I'll be running staged twin Hellcat pumps for good measure.

I hope this helps.
 

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Thanks Pat! I'm curious what the stock fuel line would allow.
The stock feed is basically -6 and will flow 1100LPH at 70psi by the charts I've looked over. Based on the replies above -6 and -8 don't matter compared to my personal results. Now if you double up two Hellcat pumps reason would suggest -8 would offer more head room.
 

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Nice! Do you think 1k on E85 is possible with 2 of them?
I think it would be worth trying. Biggest factor with be what boost you need to run to get there, followed by what lambda you target (which uses up the fuel VERY fast).
 

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Toyota Powertrain Guru
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Why would a pump that is OEM in a road vehicle cause cavitation by heat? I find that pretty funny. It’s essentially the same rotor design as the 455 with a slightly more powerful motor and no check valve to increase flow (IIRC). You can’t use a pump without a check valve as a secondary as it will back feed from the primary.
 

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Why would a pump that is OEM in a road vehicle cause cavitation by heat? I find that pretty funny. It’s essentially the same rotor design as the 455 with a slightly more powerful motor and no check valve to increase flow (IIRC). You can’t use a pump without a check valve as a secondary as it will back feed from the primary.
You're right. Not sure what he's saying or referring to there.

The 295 doesn't have a check valve. The 285 does have a check valve.

I believe it's the same motor but they tweaked the electrics for more amperage (so yeah, more powerful result).

It won't cavitate because of being higher amperage. Thats for sure. It will heat the fuel more, yes, but that affects knock and fuel density and that's not really a factor for us. I mean it is but it isn't lol
 

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Why would a pump that is OEM in a road vehicle cause cavitation by heat? I find that pretty funny. It’s essentially the same rotor design as the 455 with a slightly more powerful motor and no check valve to increase flow (IIRC). You can’t use a pump without a check valve as a secondary as it will back feed from the primary.
Yes it's an OEM pump. But the hellcat ECU uses pulse width modulation to regulate the duty cycle of the pump.
I'm fairly certain my AEM Infinity 712 doesn't have a PWM controller that works with these pumps. Atleast not out of the box. Therefore it's either On or Off, no modulation. I've seen first hand how hot these pumps get.

As for cavitation; as the fuel heats & expands there's a chance it could form air pockets/bubbles within the lines.

I've been told by both Jeff Tsai (owner of Powerdynamix) and Brian(owner of PHR) not to run this pump as a primary on a street car.
 

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Has anyone maxed out a single walbro 525/Hellcat pump on e85? If so, were you on the factory feed line?
To address your questions directly without underlying info: yes I used a stock feed line modified to fit 6AN stuff at the OEM filter location. The car makes 705whp practically daily in SFL without a single issue, ever.
 

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Yes it's an OEM pump. But the hellcat ECU uses pulse width modulation to regulate the duty cycle of the pump.
I'm fairly certain my AEM Infinity 712 doesn't have a PWM controller that works with these pumps. Atleast not out of the box. Therefore it's either On or Off, no modulation. I've seen first hand how hot these pumps get.

As for cavitation; as the fuel heats & expands there's a chance it could form air pockets/bubbles within the lines.

I've been told by both Jeff Tsai (owner of Powerdynamix) and Brian(owner of PHR) not to run this pump as a primary on a street car.
Brotato, you might be thinking of someone else. I certainly have never said this.

Although I agree with your premise of heating fuel. But I don't think there's any danger in cavitation because it picks up directly from the bottom of the tank and creates high-pressure, which counters cavitation. I certainly have seen boiling fuel and problems it can cause, but I don't think there's much to worry about in this particular case of running a hellcat pump as a primary. It might make good sense to reduce the volume by adding a controller to control pump speed but that adds complication and, in all honesty, I'm not too worried about it.

That being said, 450's work great, and it's my preferred go-to pump. If I need more than 1 can provide, I add a second staged pump, and if that's not enough, I add a third.

Thanks,
Bryan
 

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Brotato, you might be thinking of someone else. I certainly have never said this.

Although I agree with your premise of heating fuel. But I don't think there's any danger in cavitation because it picks up directly from the bottom of the tank and creates high-pressure, which counters cavitation. I certainly have seen boiling fuel and problems it can cause, but I don't think there's much to worry about in this particular case of running a hellcat pump as a primary. It might make good sense to reduce the volume by adding a controller to control pump speed but that adds complication and, in all honesty, I'm not too worried about it.

That being said, 450's work great, and it's my preferred go-to pump. If I need more than 1 can provide, I add a second staged pump, and if that's not enough, I add a third.

Thanks,
Bryan
Couple months ago when I picked up the new bulkhead to replace the one that melted from E85. I mentioned I was gonna get a replacement pump for my dead 450 and was considering the 525. You mentioned not to run it as a primary.

Jeff installed it for me and said the same. I just went with a 2nd 450 to avoid any potential issues.

No problems since.
 

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Couple months ago when I picked up the new bulkhead to replace the one that melted from E85. I mentioned I was gonna get a replacement pump for my dead 450 and was considering the 525. You mentioned not to run it as a primary.

Jeff installed it for me and said the same. I just went with a 2nd 450 to avoid any potential issues.

No problems since.
E85 melted what? You mean the pump melted the bulkhead connector?
 

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E85 melted what? You mean the pump melted the bulkhead connector?
Different topic. I must've had an early model of the PHR hanger. Because the bulkhead connector lacked epoxy and didn't have Tefzel wires. So overtime the e85 corroded/melted the wires.
We don't think heat was a factor.
247161
 

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Ah right. I've melted an OEM connector using twin 450s like an idiot without using bigger GA wire soldered to it. And the pumps weren't staged so it was 40AMP of draw 24/7 in Florida heat lol didn't go so well and is the reason I soldered in 12GA to the single Hellcat pump in the wait for the Radium hanger and my fuel lines to go in. Doing some trick dry breaks so I can just pop my filter out when I change the oil.

But that makes sense what you were saying. Meh. I don't think 10% more amps will make as big of a difference as you think. That's all my point is.

Have a great night and good chatting with everyone. If you want to have the chat in a more streamlined way... Check out our Facebook group in my signature. All 100% MKIV Owners.
 

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I run all my primary fuel pumps off the factory fuel pump ECU. 50% duty cycle until you get to atmospheric manifold pressure then 100% output. It drops the pump amperage to a little over a third of maximum. Contrary to popular belief, there is zero voltage or current drop through the ECU. If you modify the MAF signal on the OEM ECM it will drive the pump slowly but with a ProEFI etc, it’s a great option to help keep the circuit from being overloaded. No reason to remove it.
That said I hope people using the 525 pump as a secondary are doing something like the radium check valve.
 

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I run all my primary fuel pumps off the factory fuel pump ECU. 50% duty cycle until you get to atmospheric manifold pressure then 100% output. It drops the pump amperage to a little over a third of maximum.

That said I hope people using the 525 pump as a secondary are doing something like the radium check valve.
1) the 525 does have an internal check valve. Not sure where this is coming from. If you purchase a 285 it has a check valve. If you purchase the 295 for "max flow" it does not have an internal check valve.

2) What is the wiring process for setting up the OEM fuel pump ECU? You don't run any larger wiring to the pump hanger? Even with 12GA wire to the pin on the connector of the hanger it still gets warmer than it used to. Maybe 10° above ambient after 2 minutes.

I am very interested in being able to PWM the primary down with my Infinity. That would be really nice. Can someone explain how that would work?
 
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