walbro295 + stock hpfp limits

driver01

Lurker
Nov 25, 2022
16
1
0
hi

i have walbro 295, standard hpfp and bored hole on rail to get more pressure. injectors are index 12

hydra800 turbos are on car, 24psi, I got rail pressure just 1200 psi (1500 max) on wot.

is that limit of that fueling setup? or hpfp can be shoot
 

ShocknAwe

Captain
Jan 24, 2018
1,573
1
801
0
Charleston, SC
Ride
N54/3 1er ///Mutt
Probably. I was at 22psi on 93 with my N53/800 setup at one point and HPFP pressure with the 295/535 pump was around 1k-1500. I added some timing back in and at 18psi now car likes it better. Assuming you're adding octane somehow for 24psi.

How much rail pressure did you get before and after drilling it and removing the inline filter?
 
  • Like
Reactions: wheela

Paarma78

New Member
Oct 15, 2023
26
12
0
Finland
24psi with HP800 is a lot if E-mix. I have 25-26psi (different turbos, ~550hp on crank), E45 mix and HPFP (new genuine) is dipping almost to 1000psi. Could be injector issue too as I have a selection of different index ones from previous owner. I have a set with index 12 and PFS POD waiting installation to fix the rail pressure issue. Long winter in Finland until I can validate that the rail pressure is fixed...so my guess is that you need OD or PI or lower your boost...
 
  • Like
Reactions: driver01

IQraceworks

Sergeant
Jul 7, 2020
262
153
0
Missouri
Ride
07' BMW 335i
Sounds like you are pretty much at the limit of the HPFP. I'm at 25psi on RB2's on an E40 mix making close to 575-600hp, and rail pressure starts dropping towards the top end of the track....getting down around 1,500psi. The pump just can't keep up.
 
  • Like
Reactions: driver01

driver01

Lurker
Nov 25, 2022
16
1
0
Sounds like you are pretty much at the limit of the HPFP. I'm at 25psi on RB2's on an E40 mix making close to 575-600hp, and rail pressure starts dropping towards the top end of the track....getting down around 1,500psi. The pump just can't keep up.
ok. so at around 650-700hp, its to expect that hpfp will drop on 1200 psi? and cannt go under 1800 in best cases on higher rpms
 

driver01

Lurker
Nov 25, 2022
16
1
0
Can you reword that? I'm not realy sure what you are asking. Thanks
on that power (700 hp) is normal that hpfp will drop to under 1500 psi on wot?

and canot go over 1800 psi at best

doesnt mean pump is bad, just cannot handle power?

as I have dillema to order hew hpfp
 
  • Like
Reactions: Shevin95

IQraceworks

Sergeant
Jul 7, 2020
262
153
0
Missouri
Ride
07' BMW 335i
on that power (700 hp) is normal that hpfp will drop to under 1500 psi on wot?

and canot go over 1800 psi at best

doesnt mean pump is bad, just cannot handle power?

as I have dillema to order hew hpfp
Most people don't even see 600hp without the HPFP not being able to keep up. Honestly, I doubt you are making an honest 700hp with the stock DI setup. So to answer your question....your HPFP is fine, it's just maxed out. You should start looking into a port injection system. It's odd that it won't make over 1800psi.....but that could be an issue with your rail pressure sensor.
 
  • Agree
  • Like
Reactions: wheela and driver01

ShocknAwe

Captain
Jan 24, 2018
1,573
1
801
0
Charleston, SC
Ride
N54/3 1er ///Mutt
Yep my hpfp goes over 3k.

Power/psi discussions are moot really. 93 or e-mix you either need more fuel or you don't to have an adequate AFR. Upgrades to HP/PI and then LPFP to support will be required.

Example, 21-22 psi with HP800 and N53 head at 7500-8k rpm and ~11.5 AFR on 93 pump running through stock HP and single bucketed 535lp and I'm out of fuel likely on both HP and LP side. I'm planning to spray a little meth to smooth it out and reduce temps as well, for my head I have no need for more than this I can't put it down.
 
  • Like
Reactions: wheela

driver01

Lurker
Nov 25, 2022
16
1
0
Most people don't even see 600hp without the HPFP not being able to keep up. Honestly, I doubt you are making an honest 700hp with the stock DI setup. So to answer your question....your HPFP is fine, it's just maxed out. You should start looking into a port injection system. It's odd that it won't make over 1800psi.....but that could be an issue with your rail pressure sensor.
understand. rail sensor is low press sensor?

also, is possible to compensate a bit with wmi? not full wmi map, just partially to help with afr
 

wheela

Captain
Jun 4, 2021
1,349
780
0
Twin Cities, MN
Ride
2015 e84 X1 35i Msport
understand. rail sensor is low press sensor?

also, is possible to compensate a bit with wmi? not full wmi map, just partially to help with afr
I don't think you want to compensate a hpfp that can't keep up with water/meth.

Like the others said, you could add PI, or if you'd like to stick with DI look into PFS POD, people seem to have good luck with thatđź‘Ť