Upgraded LPFP or HPFP needed for FBO (full bolt ons) and stage 2/2+ tune?

panwifi · 09-22-2024, 12:14 AM

Title, also new to modding

If an upgraded LPFP is needed, should i go bucket or bucketless and what are the pros and cons? i'm not sure about anything with HPFP so any info is great help, thanks.

'11 e93 335is

HighLifeKJ · 09-25-2024, 09:17 PM

Get a 535lph pump bucketed and youll be good for simple bolt ons. Only differences w/ a bucketless system is you shouldnt let your gas level get low nor should track the car since there isnt a bucket to siphon fuel from at low levels.

lookalikehuuh · 10-01-2024, 01:08 PM

To answer your question, upgraded LPFP is ONLY needed in 2 cases:

1. The factory fuel pump is not able to keep up with the fueling requirements of your tune, always log a few runs in 3rd (or 4th if you have a crazy long runway i guess) to ensure low pressure fuel pressure remains above 60PSI, anything below 60 PSI requires an upgrade.

2. You run an E85mix tune above E30. This also has the same caveat of ensuring your pressures remain above 60PSI at all times.

Also keep in mind that most people don't take into account that an upgraded LPFP will REQUIRE that your EKPM be actively cooled. This is something people don't point out often and will cause all kinds of issues, even on brand new EKPM modules.

New HPFPs are needed when rail pressures drop below 1800-2000PSI under load. I think people that run full E85 tunes sometimes install overdrive kits on their HPFP, but I have seen failures and design issues with those. For the rest of us as long as your HPFP is healthy then no need to upgrade. I have run E60 on the stock HPFP with no issues.

09-22-2024, 12:14 AM	#1
panwifi Registered 0 Rep 2 Posts Drives: 335is e93 convertible Join Date: Sep 2024 Location: Loudoun County, VA iTrader: (0)	Upgraded LPFP or HPFP needed for FBO (full bolt ons) and stage 2/2+ tune? Title, also new to modding If an upgraded LPFP is needed, should i go bucket or bucketless and what are the pros and cons? i'm not sure about anything with HPFP so any info is great help, thanks. '11 e93 335is
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09-25-2024, 09:17 PM	#2
HighLifeKJ New Member 2 Rep 7 Posts Drives: E92 335i N54 Join Date: Jul 2020 Location: Goldsboro, NC iTrader: (0)	Get a 535lph pump bucketed and youll be good for simple bolt ons. Only differences w/ a bucketless system is you shouldnt let your gas level get low nor should track the car since there isnt a bucket to siphon fuel from at low levels.
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10-01-2024, 01:08 PM	#3
lookalikehuuh Lieutenant Colonel 997 Rep 1,516 Posts Drives: 2006 330i, 2007 335i Join Date: Sep 2014 Location: San Diego, CA iTrader: (0)	To answer your question, upgraded LPFP is ONLY needed in 2 cases: 1. The factory fuel pump is not able to keep up with the fueling requirements of your tune, always log a few runs in 3rd (or 4th if you have a crazy long runway i guess) to ensure low pressure fuel pressure remains above 60PSI, anything below 60 PSI requires an upgrade. 2. You run an E85mix tune above E30. This also has the same caveat of ensuring your pressures remain above 60PSI at all times. Also keep in mind that most people don't take into account that an upgraded LPFP will REQUIRE that your EKPM be actively cooled. This is something people don't point out often and will cause all kinds of issues, even on brand new EKPM modules. New HPFPs are needed when rail pressures drop below 1800-2000PSI under load. I think people that run full E85 tunes sometimes install overdrive kits on their HPFP, but I have seen failures and design issues with those. For the rest of us as long as your HPFP is healthy then no need to upgrade. I have run E60 on the stock HPFP with no issues.
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