Thread: HPFP swap
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IK6SPEED IK6SPEED is offline
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Posts: 41
Join Date: Mar 2019
Car: BMW
Default 03-05-2019, 02:32 PM

Originally Posted by T_H_O_M_A_S
such a pump isnt rocket science . simple but sturdy plunger design , an internal bleed valve and a an input control valve . your dme's sets a rail target and the pump tries to follow suit , it doenst care what turbo or else is mounted
it just tries to do what the dme asks . and if it cant hold up , your rail pressure drops , notice the pulsation dampener on top

You made +14bhp peak power with the upgrade than with your older N55 OEM stock pump with all your other upgrades and PS2 Turbos. Stock turbo and other OEM parts would make less than that.

And if power isn’t the bottom line, what is?

EDIT: Had datalogs reversed. B58 HPFP actually made 14bhp LESS peak than stock

Originally Posted by DB90

It’s common for a tuner to target a lower rail pressure when using the oem hpfp, especially when you are on the edge of what it can flow.

You need to factor in load/boost, afr and iat’s to get a decent picture of how the hpfp is managing. Just because your oem hpfp held 2600psi doesn’t mean it’s stronger.

You can quite clearly see the oem hpfp struggling to maintain the requested 2000 psi, after adding the evo hpfp it maintains this without issue. The requested 2000 psi won’t change until the tuner changes this in his tune.

Another source has stated this pump flows 13% more over the oem. Going off of this it isn’t as strong as the xdi-35. However that 13% should run some decent numbers on a ps2 and certainly max out the oem turbo. We won’t know for sure until someone tests and tries.
I see the upgrade still struggling to hold 2000 PSI.

Regardless, some people would rather run on lower pressure and on the ragged edge over 2k. Well wait till the first one blows up and a used engine is 15K installed.

Tuners lower pressure to put squeeze a little further however the problem still is the problem. If that's the solution then turn the requested pressure to 1800 and the stock pump will hold 18 psi, no need for an upgrade. One could tune with 18 psi low fuel pressure and no timing and could make 350 hp. Which would not require a pump at all.

AGAIN, who cares how much boost if your not making power.

XDI or PI is night and day over this. Certainly more than 14bhp with a PS2 and all the other upgraded parts.

EDIT: Had datalogs reversed. B58 HPFP actually made 14bhp LESS peak than stock

Last edited by IK6SPEED; 03-08-2019 at 08:38 PM..
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