Quick FPR question: Diagram Inside

[Aust162]

Hi everyone. I want to make sure the Sard FPR i fitted is correctly hooked up. Here is the diagram: its a 3sgte rail with standard FPR still in place. There was a vacc line connected to the ORIGINAL FPR (marked in blue).



Question 1: Does this vacc line now need to go to the sard unit? And if so, do i block the vacc inlet on the old FPR, or leave it uncovered? Or do i also give it vacuum?

2. When setting up the sard unit, how do i set the pressure? its 42psi base pressure. do i set this at idle? hot or cold engine?

thank you

[Norbie]

1. Both FPR's require a vac signal.

2. Base fuel pressure is relative to manifold pressure. If you want 42psi base pressure you set your gauge to 42 - X, where X is manifold vacuum.

[thechuckster]

and to do that without the car running (e.g. manifold=0mm/hg vacuum), you trigger the fuel pump manually.

42psi? you sure? i thought most toyotas ran at between 33 and 38 psi

[stradlater]

Ford Performance Racing? But this is a toyota forum....

[CrUZida]

38psi for older toyota's, 42 for newer.
The change over was in 1990ish.

Why bother running a vac line to the old FPR?? You can remove it entirely if you like.

I set mine with the car running, and the vacuum line unplugged.


Also, what is your reason behind wanting a new FPR?

[Norbie]

I'm guessing that the Sard is a RRFPR and the factory FPR is being retained for factory fuel pressure when manifold pressure is negative? If this is not the case though I agree there's no reason to retain the factory FPR, it should be removed so it doesn't complicate matters.

[CrUZida]

Why would someone be using a RRFPR on a turbo motor?

I thought only cheap people used them on NA-T conversions coz they won't fork out for an ECU

[Aust162]

I was told by the dyno tuner i use to get an adjustable FPR. i'm using the stock 440's and was running out a injector cycle. I was trying to avoid changing to 540s so i could still switch my car back to the stock ecu from the wolf3d i'm using atm.

I havnt removed the stock fpr because i dont have the fittings to block inlet on the factory rail. I had my car tuned last week and the sard reg seemed to not help at all. i still ran out of fuel at 12psi at 174.8awkw. He tried 15psi+ and the a/f where getting too lean..

Now i'm not sure what to do? car has a walbro 255lph.

should i connect a vacc line to the stock reg?when setting the psi, should i do it with the engine off, or with it running and with no vacc feed?

[1200det]

Agreed a rising rate FPR isnt such a good idea , and doesnt make things easy when tuning either.

.

[Norbie]

I was trying to avoid changing to 540s

There's your problem. If you're running out of fuel the correct solution is bigger injectors, not playing silly-buggers with fuel pressure. This is especially the case when you have programmable engine management in place.

should i connect a vacc line to the stock reg?when setting the psi, should i do it with the engine off, or with it running and with no vacc feed?

These questions have already been answered. Are you reading your own thread??

[oldcorollas]

as said in other thread, something like 20% increae in fuel pressure is 10% more flow?? and pumps start getting abit iffy above 60psi or so... so check the flow diagrams for the walbro pump and compare to the flow you want.

runnign otu of fuel at 12psi (26.7 abs) and you want 15 (29.7abs), so you need at least 12% extra fuel than you have now.... ie, 490cc injectors...

540's would be perfect

how hard is it to change injectors? compared to just changing ECU?

[Draven]

the sard is not a rising rate unit...

[Aust162]

Norbie - I'm being told two different things here, thats way i asked again to verify.

Quote:
Originally Posted by Aust162
should i connect a vacc line to the stock reg?when setting the psi, should i do it with the engine off, or with it running and with no vacc feed?

These questions have already been answered. Are you reading your own thread??



Cruzida says: "I set mine with the car running, and the vacuum line unplugged."

thechuckster said: "and to do that without the car running (e.g. manifold=0mm/hg vacuum), you trigger the fuel pump manually."

Thats why i'm confused.

To throw another spanner into the equation. the Wolfkatz site is suggestion that the rail is possibly the restriction. i know people who have gone further with 440s. People in the US making 250awhp on supra pumps with an safc.


Draven - I was told this was a 1.1 reg. this is my one below.

http://img.photobucket.com/albums/v4...2/IMG_1080.jpg

[CrUZida]

I had to pump my pressure up from 42psi to 58psi to increase my injectors from 215cc to 251cc (only a temp fix).

Thats a hefty hike in fuel pressure, you can bet the pump was working mucho hard to keep that pressure up.

To go from 440cc to 540cc you'll need to increase the pressure from 42psi to 62psi.
Then add 15psi of boost on to that and your pump is pushing 77psi.
Thats a fuckload of pressure...

Get new injectors, quick retune.

[Aust162]

Cruzida - You reckon i should piss the sard reg off, fit 540s and bore the rail? thats what i'm thinking atm..