800 hp - Fuel set up. Advice

[exXU1]

:evil: Gentlemen,

i am currently building and aiming to achieve an 800 hp engine in my r32 gtr to suit the strip, a rb 30 bottm end with a modified rb 26 head etc.

I am finding it a little hard , IN RESPECT TO FUEL,to gain info on what mods i should do and what parts i should up grade to give supply a nice constant feed.

Please help or advise with:

Do i use the standard pump to feed external pumps. Can't see that working well!

What pump do i use, a up graded Nismo or the likes , in tank. Then what does it feed. Straight into the surge tank or other pumps?

Do i use my current stock rail with the 700cc Sards, or will it have to be upgraded to handle the volume in respect to the new HP? Which one, best brand or custom.

Regulators - which one will suit this aplication.

What kpa or psi should the regulator be set at?

Your input is always appreciated gents

Thankyou

[Bl4cK32]

You use the std internal pump as a lift pump to pump fuel to the surge tank/swirl pot in the boot. Then use one or two 044 bosch pumps to the fuel rail. If you wanna go nuts a twin feed fuel rail would be the bees knees

id also go for at least 800cc injectors for 800bhp.

Regulators and psi someone else can answer. Also need to find out about a different fuel filter....id assume the old ryco wont do the job in that situation

[exXU1]

You use the std internal pump as a lift pump to pump fuel to the surge tank/swirl pot in the boot. Then use one or two 044 bosch pumps to the fuel rail. If you wanna go nuts a twin feed fuel rail would be the bees knees

id also go for at least 800cc injectors for 800bhp.

Regulators and psi someone else can answer.  Also need to find out about a different fuel filter....id assume the old ryco wont do the job in that situation

OK that seems to make sense.

Twin feed, what's that all about . and who sells those?

Rather than two pumps after the surge tank , why not one larger bosch, if ican buy.

Is it for reliability?

[blk180]

i belive for 800hp at the wheels you will need a surge and twin bosch 044 pumps a trust or hks twin feed fuel rail and run braid fuel lines and the fuel reg in the middle of the rail. I think sx make 1000hp pump but most likey cost same as two bosch pump and i go 1000cc injectors with aleast two holes per injector.

my 2c Brad

[600hp]

We're useing the standard in tank feeding a Advan surge tank wich holds two bosch 910 fuel pumps. from there it goes down twin 3/8 fuel line non braided, wich feeds a SARD twin entry fuel rail wich holds SARD 700cc injectors. which is regulated by a SARD fuel reg.

We use a standard nissan fuel filter before the surge tank and another two before the fuel rail.Not sure how much this set up will flow but should be good for 800HP.

[MELV]

OK that seems to make sense.

Twin feed, what's that all about .

stops pressure drop.

everything Bl4cK32 said will work a dream

700cc injectors should do the trick.

[exXU1]

stops pressure drop.

everything Bl4cK32 said will work a dream

700cc injectors should do the trick.

Sard twin feed rail and what model regulator do you guys suggest?

[Gav]

The reasoning behind the twin feed is that the std rail actually feeds from #6 (i.e back) end first and #1 is the last injector to see fuel. It is not uncommon for flow/pressure to drop in the rail by the time it gets to the front and starve the front cylinders of fuel. The fact that in a hard launch application there is also considerable G forces pushing backward further exacerbates the situation. The problem of detonation damage in the #1 cylinder is not an uncommon event for RBs at the limit of their fuel system.

By feeding into both ends and exiting the centre, there is less likelyhood for the above to happen.

[MSRB26]

I'd go for one SX pump (1000hp) external with a surge tank. Are you looking at 800hp at the engine or at the wheels? 700cc injectors are good for just over 800hp at the engine @ 100% duty cycle so would be best to upgrade those too. Other than that a good fuel rail, reg and upgraded lines.

[Mintie]

u will need a bigger surge tank about 5L or more. try running it with a bigger then standand fuel pump from fuel tank to surge(like 040 bosch)....and 2 bosch 910 or even bigger 044...feeding 2 end of the fuel rail and ret in the middle with regulator. this would hold up to 1000hp.........

[PurpleR32]

I have one in Tank feeding a surge tank.

From there two bosch 044 go to a twin entry greddy fuel rail. 1000cc injectors and a sard fule pressure reg.

One VERY important thing to make sure you get right is the return line.

[BBQ]

I have one in Tank feeding a surge tank.

From there two bosch 044 go to a twin entry greddy fuel rail. 1000cc injectors and a sard fule pressure reg.

One VERY important thing to make sure you get right is the return line.

As Purple R32 has said... But lots of people forget about the Fuel Pressure Regulator...

Very important when running 1000cc injectors and Twin 044's... Make sure you don't by a cheep regulator & make sure it can handle the Fuel pressure you are going to need to run... eg 100psi + !! Also have good quality EFI hose clamps. and Good quality EFI Hose.

As long as you have a decent in tank pump the return line shouldn't be too much to worry about... eg Bosch 040 in tank should be ample..

And a high pressure fuel filter would also be advisable... not cheep though..

If your setup is just for strip use only.. Don't worry about intank setup. Just run a few cell and run your main pumps straight out of that, As you fuel cell would be located in your boot.

[Mintie]

and also ..take into account of the noise that the bosch 044 will make..... my fuel pump is louder than my exhaust...

[sproosy]

Heaps of fuel stuff here: http://www.horsepowerinabox.com/HPIAB2/cat...ategory10_1.htm

Have a look on the 2nd and 3rd page. Lots of 700+ hp fuel stuff there!

[exXU1]

Onya fellas , all good avice, shedding a little light on the subject now.

For 800 attw . strip/ drag

intank -standard gtr fuel pump ? to surge tank ( 5 ltrs , sounds large ? ) from the surge via 2 x o44 and fuel filters to twin feed rail. Which side of the fuel lines does the regulator go . On the return ( dosen't sound right) or supposidly two, one on each in comming line to the rail?

.injectors - 1000cc, what cycle?

If so , my 700 Sards are for sale. My stock GTr head with 264/264 is for sale also, as well as the bottom end , currently together and in good condition.

Heaps of fuel stuff here: http://www.horsepowerinabox.com/HPIAB2/cat...ategory10_1.htm

Have a look on the 2nd and 3rd page. Lots of 700+ hp fuel stuff there!

[BU5TER]

surge tank to twin pumps to filters to each end of fuel rail with return coming from centre of fuel rail to fuel reg from fuel reg returns to surge which then has a return to tank

[Sydneykid]

The single Bosch 044 supplies enough fuel for ~730bhp at 12 volts. But you will have to use a relay and wire it back to the battery/alternator as the standard wiring won't handle the current. So the 044 will see 13.8 volts, which puts it up around 840 bhp. You don't have to run a surge tank for drag work, just make sure there is enough fuel in the tank for each run. So you could mount the 044 in tank.

From experience, the Sard 700 cc injectors usually flow around 730 cc's on the flow bench at 38 psi. The Bosch 044 is capable of 73.5 psi, so it depends on how much boost you are running as to how much you can increase the rail pressure. Around 45 psi rail pressure will see the Sards flow around 800 cc's, that leaves 28.5 psi for boost (1.9 bar).

The standard fuel rail is as large internally as most aftermarket rails, the only issue is the fittings. I am not a fan of rubber hoses and screw clamps on fuel supply at up to 73.5 psi. A bolt on Nismo fuel pressure regulator ($180 from Nengun) will fix one end, but the other (fuel supply) end of the rail will need to have a proper dash fitting welded on. I strongly suggest using bolt on fittings all the way back to the pump, fuel fires are ugly.

Personally I would save some money and use the 044 in tank with the Sard injectors and the standard fuel rail.

[Mik]

From experience, the Sard 700 cc injectors usually flow around 730 cc's on the flow bench at 38 psi.  The Bosch 044 is capable of 73.5 psi, so it depends on how much boost you are running as to how much you can increase the rail pressure.   Around 45 psi rail pressure will see the Sards flow around 800 cc's, that leaves 28.5 psi for boost (1.9 bar).

Sydneykid, can you please explain this bit? I would have thought that with a pump capable of 73.5PSI, you could theoretically run a rail pressure of 73.5 PSI.

I think your saying the the boost pressure will stop fuel from leaving the injector, but I don't understand why?

[Shaun]

Yeah,

Im modifying my standard rail and welding on dash fittings (#6 or #8, i hevent decided yet), to accomodate larger braided fuel lines and twin entry. Im running solid lines under the car tho. Im not paying abot $300 for an aftermarket fuel rail when the standard (modified) one is just as good.

[Sydneykid]

Sydneykid, can you please explain this bit? I would have thought that with a pump capable of 73.5PSI, you could theoretically run a rail pressure of 73.5 PSI.

I think your saying the the boost pressure will stop fuel from leaving the injector, but I don't understand why?

In order for the injector to squirt, it has to have a higher pressure behind it (in fuel) than the pressure in front of it (boost). If I had 20 psi total fuel pressure and 20 psi boost, no fuel would flow.

In the previous post I expressed "rail pressure" as the amount of pressure above boost. The reality is the total pressure in the fuel rail itself is fuel pressure plus boost, hence the need for screw on fittings.

Hope that clarifies:cheers: