So im clear: a single walbro 535lph (295) pump w/o a check valve is fine for our cars on startup?

[TheObjectivist]

Hi all - 2008 535i E60

My LPFP is crashing so time for an upgrade. Precision Race works sells a unit for my car using the newest F90000295 (535 lph) fuel pump.

I understand this pump is an amazing performer (as per PFS, the 450 pump isnt even an upgrade on the 5 series cars since stock is so strong), but I am concerned about long startup times since the 295 doesnt run a check valve.

Can anyone confirm that on a 5 series, the 295 pump is a good choice?

NOTE: the 5 series pumps seem considerably different than those from 3 and 1 series so Im struggling to find reviews. PR is the only company that even lists an option with this on a 5 series

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[SLOWESTN54]

i have a 450 in my car and its struggling, the 535 should be a perfect upgrade.

 

[TheObjectivist]

i have a 450 in my car and its struggling, the 535 should be a perfect upgrade.

Do you have any concerns that the pump will cause startup issues? Im unfamiliar with how sensitive our cars are to pumps without check valves

 

[SLOWESTN54]

Do you have any concerns that the pump will cause startup issues? Im unfamiliar with how sensitive our cars are to pumps without check valves

Your car will long crank start if it's been sitting.

 

[Silent11]

mine starts up fine even sitting for a week or two. I had the same concerns but i dont see any difference from the other upgraded pumps with a check valve

 

[TheObjectivist]

Your car will long crank start if it's been sitting.

Sad noises. This is def concerning

 

[TheObjectivist]

mine starts up fine even sitting for a week or two. I had the same concerns but i dont see any difference from the other upgraded pumps with a check valve

Wow. Everything with your 295 install works as if stock ? e.g, you open the door, whirr of fuel pump, you then push the starter and it fires right up?

I just heard from precision raceworks and theyre saying it will work without startup issues too, so its like half of users indicate its a long start and the other half say its fine


I assume youve a 3 series?

 

[Silent11]

Wow. Everything with your 295 install works as if stock ? e.g, you open the door, whirr of fuel pump, you then push the starter and it fires right up?

I just heard from precision raceworks and theyre saying it will work without startup issues too, so its like half of users indicate its a long start and the other half say its fine


I assume youve a 3 series?

e92 335i

Wow. Everything with your 295 install works as if stock ? e.g, you open the door, whirr of fuel pump, you then push the starter and it fires right up?

I just heard from precision raceworks and theyre saying it will work without startup issues too, so its like half of users indicate its a long start and the other half say its fine


I assume youve a 3 series?

335i here, no issues with starting. I have other issues with fueling currently but i had same issues with a 525 so its not the new pump that is causing it. All good with startup.

 

[nyt]

I run a pair of 535s. There is virtually no delay on startup. Pressure drops to 0 as soon as the car is off with my setup (external fpr and filter and return line).

The HPFP rail will hold pressure for some time, and even when sitting for a while, it still starts quickly.

 

[fmorelli]

One can always run an external fuelabs filter with check valve ... E85 safe version if necessary ... and remove then HPFP filter.

 

[RNM]

I have a 335i and I don't have any start up issues with the 295 walbro pump and full e85 (I live in FL.)

 

[TheObjectivist]

Great. def seems the 295 pump is the way to go

Only concerns now:
1. does PR engineer their pumps well enough where the pump doesnt outflow the bucket (i saw a vid showing how some vendors dont know what theyre doing lol)
2. will my EKP be able to keep up

Ill order now and hope for the best

thanks all

 

[TheObjectivist]

One can always run an external fuelabs filter with check valve ... E85 safe version if necessary ... and remove then HPFP filter.

Would an external check valve incur an amperage penalty?

From what I read, the 295 uses nearly the same power as a 450 (+1 amp) whilst outflowing it. Many posts attribute that to the missing check valve. Maybe if the valve is external its not a restriction?

 

[KAIZZER]

Simply "prime" the pump before attempting to start the car. I usually wait 3-5 seconds or so.

 

[SLOWESTN54]

Simply "prime" the pump before attempting to start the car. I usually wait 3-5 seconds or so.

The pump typically primes when you unlock it, or open the door.

 

[KAIZZER]

On my car (E89) it makes a stark difference whether or not I put it in accessory mode vs just attempting to start it off rip which is why I made that suggestion. I legit have to prime the Z before cranking it or it sounds terrible once it fires up.

 

[fmorelli]

On my car (E89) it makes a stark difference whether or not I put it in accessory mode vs just attempting to start it off rip which is why I made that suggestion. I legit have to prime the Z before cranking it or it sounds terrible once it fires up.

Why is this? I can't come up with a reason. When you unlock or open your door, do you hear the pump priming?

 

[fmorelli]

Would an external check valve incur an amperage penalty?

From what I read, the 295 uses nearly the same power as a 450 (+1 amp) whilst outflowing it. Many posts attribute that to the missing check valve. Maybe if the valve is external its not a restriction?

Check the graph out here:

DIY - E89 Z4 fuel system - DI only LPFP / HPFP

Having pretty much wrapped up the suspension and brakes on the Z4, my next phase is to upgrade the fuel system. This is precursor work, preparing for the VAC ported head, Schrick cams, Hydra HP650 turbos and clutch. My plan has always been to be DI only, with a target of 600whp. A bit of...

www.spoolstreet.com

As or check valve - I think it is a function of how/where the valve is in the pump itself. I don't believe the external valve has the same kind of restriction. Good question, though - this should get nailed down.

 

[Cruizinmax]

I've started the car up with the lpfp completely disconnected and it started right up, no delay. I obviously can't say if that's always going to be the case since I've only done it a few times in my career.

Other platforms most definitely are effected by not holding residual pressure but on this one, maybe not so much.

 

[KAIZZER]

Why is this? I can't come up with a reason. When you unlock or open your door, do you hear the pump priming?

I am not entirely certain, but this is the way it has been since the day I upgraded to the 535lph pump. Doesn't seem to have any other adverse effects and does the job as far as I can tell. 2 going on 3 years strong.