Hi capacity Fuel Pump and Fuel Economy

[adam 32]

ive got a 910 and fuel economy has gone down as a result of this.

i know technically the fuel reg should keep rail pressure constant but it doesnt work. when i first installed the pump it ran mega-rich. have sinced installed an AFC but even on 1 bar it still aint too efficient

[T0nyGTSt]

What regulator is it?

I get a reasonable 400km to a tank. I really do not want this to dive down to 300km...

T.

[drifto]

When i bought my 32 it had a 33GTR fuel pump to help with boost levels of over 17psi.

With the AFC and ITC tuned to perfection the car tended to ping at high rpm due to lack of fuel. However the pump and injectors are easily up to supplying an RB20 with only 200 or so KW.

I had a rising rate fuel regulator fitted and set it at 4psi above standard.

Pinging stoped immiediatly but it now uses heaps more fuel. Not so much just on boost but just starting the engine and dribling around town.

The car almost chokes on fuel around town and you can here it discarding extra fuel through the exhaust with pops, burbles and sometimes a loud bang!

All sound good to me if you don't mind a few extra $$$$$ a week in fuel.

This could all be bullshit though because the garage that sold me the fuel reg @$280 plus $30 to install also did the dyno tune @ $80 plus $40 to adjust tune. When all they may have done is tuned the fuel/air ratio to be richer.

[R31Nismoid]

I'll post up in a week or so as i'm upgrading to the 044 (700hp)

noise doesn't bother me diddly squat as all the sound deadening in the boot had been ripped out before i brought the car.

So i guess i'm the guinea pig here. I have to get something bigger as i've got no fuel as it stands.

If i loose 50km per tank that won't be too bad... but anymore and i won't be happy !

stay tuned

[macka]

Well i just clocked 280km on 55 lt

910 Bosch pump

Malpassi reg

10 psi boost

AFC tuned

The last dynotune showed that it wasnt too rich but still look at the economy.

[R31Nismoid]

FUC* ME!

i get around 350-400 on 9psi atm (but i got BIG turbo and the car is thirsty)

we'll have to see.....

[macka]

bye bye 400km to tank

[T0nyGTSt]

Hmmm... this looks bad.

A regulator would cut the flow if possible?

No?

I have a Bosch 040 on order as well :-(

T.

[ed]

I was told it is best to get the regulator adjusted/checked again if you change/add a fuel pump?

[macka]

Yes Ed definately

U can usually knock it down a touch on the dyno

[Steve]

Macka, the question beggs asking - how much time do you spend OFF boost?

[GTS-t VSPEC]

Macka drives pretty hard, but not on boost all the time. I get about 370 from mine, but planning on having a 2nd map in my Wolf for fuel ecomony, and switch between the two, depending on driving conditions:D

[predator]

i don't think the pump is the main problem in these cases.. you play with the a/f ratios to get more performance you're gonna use more fuel.. To get that right ratio, if you need another pump, then your ratios are tuned accordingly.

v-spec: 2 maps would be great for everyday driivng. Prob is you tune for highboost most of the time, so when you're running low boost you waste the extra fuel. oh well.. if u don't like it: remove fuel pump altogether and 100% fuel economy

[macka]

Hey Steve

Since ive had my car back ive been cruising all the way...squirt here and there..and 1 drag

Ive had the car back for almost a week and on the 1st tank that is what i recorded.

Off boost fuel is the killer not on boost it seems If i drive it hard the economy doesnt get much worse

Predator i think the whole playing with the fuel system is the problem

Pump,Turbo change,Intercooler,BOV,Airpod change,Fuel Reg and SAFC all play a part i think

[adam 32]

my fuel economy is nowhere near that bad

RB20DET

Bosch 910

on 10psi i get about 400-450km a tank

on 14.5psi i get about 380-400km a tank

[R31Nismoid]

smaller engine... lighter weight

[adam 32]

haha go the 32

[Cubes]

When I had my 910 fitted it did run richer and lost quite a bit of power. The mid range also felt flatter.

I didn't notice a drop in fuel consumption as if i press the odometer fill the tank I will still hit 470 as the red light flicks on.

The lowest I have hit was 400km's per tank on 15psi of boost hammering through the hills.

I have got different injectors however. They are C18 370cc Injectors. Maybe they are super clean or some thing?!?!

[Cubes]

Just a thought.....

According to the specs..

An R32 is supposed to get 10.5L per 100km's.

An R33 is supposed to get less than a R33 per 100km's.

I have also heard of near stock R32's also getting bad fuel economy which to me is under 400km's per tank.

Maybe the O2 Sensor isn't working correctly and causing the car not to enter closed loop mode quick enough combined with possibly dirty injectors???

[Sydneykid]

Hi guys, if the air fuel ratio is tuned at 12 to 1 all through the rev range. The ECU will add 1 part of fuel to 12 parts of air. It does not matter whether you have a standard pump, a GTR pump or a Bosch pump. My suggestion when you change fuel pumps and/or fuel pressure regulators is always to get the A/F ratios checked on the dyno, costs less than a tank of fuel. This will also show up any lambda sensor problems.

Dirty injectors restrict fuel flow, that would improve fuel economy and increase risk of detonation. I have seen dirty injectors increase power as the car was running rich.

Hope that helps