HiProfile

I was curious about running 2x GSR OEM fuel pumps. I'm not shooting for 500+ whp on my D16, just the occational blast to 18psi on a smaller turbo, so really 300whp tops atm.

I was wondering since I have 780cc injectors, should I put a check valve (or remove) the vac line to the FPR? Since it takes 2x the volume to make 2x the power BUT takes 4x the pressure to make 2x the flow, 2 'weak' 200whp pumps at 43psi max should have no problems with even the 350whp-ish S-trim I have availible. I'm swaying towards a check valve since I'd technically be able to control idle better (of which 780's idle it perfect atm).

The reason I ask this is because I can machine my own tank 'cap', allowing the use of 2, and I can get the OEM pumps very cheap vs Walbro.


BTW please don't waste your OR my time with a lame 'get a walbro' one-liner. I *HAVE* one, its just for my other car.

Riake

What regulator do you have? If its stock and you remove it, wont it rise to 50psi or so? I know my GSR had a base pressure of 42 but would rise when I took the line off to adjust it. I have a B&M regulator. I am looking to replace soon, because I have heard of some 'stories' that have me worried.

If you are confident in your calculations then go for it. You seem intelligent in all of your other posts to make a smart decision, why would this one be any different?

HiProfile

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Riake &raquo;</TD></TR><TR><TD CLASS="quote">What regulator do you have? If its stock and you remove it, wont it rise to 50psi or so? I know my GSR had a base pressure of 42 but would rise when I took the line off to adjust it. I have a B&M regulator. I am looking to replace soon, because I have heard of some 'stories' that have me worried.</TD></TR></TABLE>

I don't care about the acutal psi, just that it doesn't go up another 18psi when I'm boosting. There's a point where extra fuel pressure actually decreases overall flow. Anyways I thought at WOT it should be around 43.5psi. The stock FPR lowers fuel pressure with vacuum, just as it increases it with boost pressure. Removing that line at idle changes its signal from ~21 Hg" (3.5psi absolute) to ~0 Hg" (14.5psi absolute).

HiProfile

Just thought I'd come back and share what I've found. I'll be doing this later this winter, just need the pumps to get here (was a mix-up on what type to send). I should be getting 2 complete assemblies soon for a 96 GSR, so all I need to do is make a cover/arms like the one that holds dual Walbros.



I've been doing the math here, and if I was to run 2x GSR's at 43.5psi, thats about 250 lph max. Considering a Walbro 255 will do 255 lph (hence name), which is enough for ~550whp at ~60psi, which is roughly the same amount as 2x GSR's, I could only say this would work great. Even if you assume they have issues sharing the same size fuel line, this would be fine for even 450whp - more than enough for pump gas.

The only issue is that I'll have to re-wire the supply with bigger wires, but thats a good idea with a Walbro too. I'm working/doing school to the extent I'd much rather make something than put in more hours at work to buy something.