LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Bigger fuel pump setup needed?

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Old Jul 20, 2016 | 09:01 AM
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Default Bigger fuel pump setup needed?

With my new top end setup, I am wondering if I will need to upgrade to an even bigger fuel pump setup now? Setup in sig, 385ci, E85 fuel, AFR LT4 210 Comp, 60# Siemens injectors, turning to 7k RPM. I am currently running a single Walbro 255 but am thinking I may need to go bigger to support the top end power and E85. Any suggestions?
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Old Jul 20, 2016 | 10:20 AM
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E85 needs ~30% more fuel which means a 255 will be maxed out at around 450chp on E85. It will be close to the limit depending on how much hp you are making so I would step up to a bigger pump to be on the safe side.
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Old Jul 20, 2016 | 11:24 AM
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I should be well past the 450chp limit with my setup, closer to the 600chp mark. I know there are a few guys running high hp E85 setups on here. What kind of fuel pumps are you guys running?
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Old Jul 21, 2016 | 10:05 AM
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You may need to upgrade by adding a second pump, but I think you will be ok.
The rating figures are very subjective.
To be sure add a pump, or stay as is an monitor fuel pressure and AFR.
If you are out of pump, you will see an almost linear leaning as you hit higher Rpms.
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Old Jul 21, 2016 | 11:05 AM
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You can swap in an Aeromotive 340 LPH and upgrade to a Racetronix hot wire kit like I did. I previously ran a Walbro 255 LPH as well. Easy, simple swap once you get the tank down.GL
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Old Jul 21, 2016 | 11:10 AM
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Originally Posted by AgFormula02
You may need to upgrade by adding a second pump, but I think you will be ok.
The rating figures are very subjective.
To be sure add a pump, or stay as is an monitor fuel pressure and AFR.
If you are out of pump, you will see an almost linear leaning as you hit higher Rpms.
I'll try to test out the pressure and AFR at 7k WOT this weekend. Hopefully I won't need to upgrade the pump, but I'm thinking that I may need to.
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Old Jul 21, 2016 | 11:13 AM
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Do you have the hotwire kit?
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Old Jul 21, 2016 | 11:28 AM
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Originally Posted by myltwon
Do you have the hotwire kit?
I do not, I have the regular 255 upgrade kit from Racetronix. I may just do what BOLO suggested and go with the 340 and hotwire kit just to make sure I'm good on fueling. I already have the trap door setup so it shouldn't be to big of a deal to swap it out again.
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Old Jul 21, 2016 | 03:21 PM
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Another option is a boost a pump which will spike voltage to the pump and increase output at wot.
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Old Jul 30, 2016 | 10:07 AM
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One really good option is the walbro 450 e85 pump and a Hotwire kit. Supposed to draw a little less amperage than a 255 due to a better motor, but obviously much more fuel.
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