djnikko

I have a Walbro 255LPH fuel pump and am wondering before I install it how I can tell which pressure it is? I have heard they do a 255LPH in high and low and I need the low.... Is there a specific part number im looking for? I dont wanna go installing the wrong one
Thanks in advance

b18psi

Why do you have to have a low pressure?

djnikko

I dont but from what ive read having the high pressure with a B&M FPR (which is what ive got) will leave me with a minimum of 50-60 PSI base line fuel pressure, can someone confirm this for me please? I reckon I need something higher flow rate than the stock pump but not mega high... im looking for 200-400HP, which pump would suit my use?
thanks in advance

99lspwr

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by djnikko &raquo;</TD></TR><TR><TD CLASS="quote">I dont but from what ive read having the high pressure with a B&M FPR (which is what ive got) will leave me with a minimum of 50-60 PSI base line fuel pressure, can someone confirm this for me please? I reckon I need something higher flow rate than the stock pump but not mega high... im looking for 200-400HP, which pump would suit my use?
thanks in advance</TD></TR></TABLE>


255 low pressure will be fine if you are going to be using a decent sized injector...If you plan on doing an fmu type set-up get the high pressure, otherwise just stick to the 255 lp one..

Full-Race Geoff

use the 255 High Pressure all the time. There is no advantage to the low pressure. The high pressure pump is the best for any turbo honda application. You can tell if you have it by checking the part number. The high pressure pump is a 341

b18bturbo

341 or 342 depending on which model you ahve is the high pressure pump gss317 is the low pressure model

Tchleung

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by djnikko &raquo;</TD></TR><TR><TD CLASS="quote">I dont but from what ive read having the high pressure with a B&M FPR (which is what ive got) will leave me with a minimum of 50-60 PSI base line fuel pressure, can someone confirm this for me please? I reckon I need something higher flow rate than the stock pump but not mega high... im looking for 200-400HP, which pump would suit my use?
thanks in advance</TD></TR></TABLE>

I thought so too, but I put in a walbro 255LPH HP pump and I can adjsut my pressure below 40. I have it at about 45 with vacuum on. about 50 WOT

b18psi

I have the high pressure with Hondata engine management and 750cc RC injectors. Before Hondata I ran it with the Vortech FMU and stock injectors and it has ran great with both set ups

adseguy

Actually they both provide the exact same pressure until a certain flow rate, then the High Pressure version continues to deliver the same amount of pressure while the other one starts to dip off. So in the ned if you can get both for the same price you might as well get the HP version since they both deliver the same performance only the HP will do it all the time!

djnikko

I checked earlier Ive got the 341 high pressure. how will this effect my setup? Ive got 450cc DSM's, B&M FPR on the fuelling side of things

locash

I had to edit my original post, as after doing further research, either the 255 lph low or high pressure pumps put out nearly the same flow at 30-55 psi, but the high pressure pump will continue to deliver good flow after 60 psi, whereas the low pressure pump dies off quickly.. For 300-400 hp @ 40psi rail pressure, even the 190lph pump will suffice. The stock 99 Si fuel pump, and many other OE honda pumps, will support 300 hp @ 40 psi. If you are using an FMU setup, go for the 255lph High Pressure pump to be safe.. Be aware though, at these flow rates, anything over the 190lph pump will just about require a decent fuel pressure regulator to maintain a constant 40 psi, as the stock regulator will be overwhelmed..


Modified by locash at 4:51 PM 11/14/2004


Modified by locash at 4:53 PM 11/14/2004

Pondus

I don't see a reason for not using a HP as the flow caracteristics are virtually the same up to about 60psi where the standard takes a dive and the HP keeps on delivering a godd amount well over 100psi.

Here's the flowchart :

djnikko

What FPR do you guys recommend? Ive got the B&M and I have a feeling its gonna give me grief...

Thanks for the replies

VspecSiR

under what conditions does one need to upgrade their fuel pump??? beyond 200whp??? I'm looking into getting a walbro 255lph HP pump. And currently shooting for a mild 200-220whp. Do I really need this pump? I guess I'm asking do i really need the pump to put out those numbers?

by the way i have the greddy kit for a 00' civic si.

djnikko

Im fitting one only on the basis that its better to run rich rather than lean and theres less chance of it running lean with one fitted. Im not bothered about fuel consumption as it is a second car used for the strip.

Do people have difficulty getting the correct idling pressure with a B&M FPR and a walbro 255lph? By the way im running 450dsm's if this helps.

Thanks in advance