DutchClutch

Gentlemen,

I installed a Walbro-fuelpump,and a fuelpressureregulator will be added in some time.
My car runs at 1.22something bar of turboboost.(full ECUTek-remap,aprox.280BHP)The injectors(380cc?) allmost reach there limit with 97%dutycycle at 6000-6500rpm.
To lighten up their job,and to be sure there's allways enough fuel at hand,we want to increase fuelpressure a bit.

How much should the fuelpressure rise above the standard pressure?

And perhaps anyone with experiences on that one?


Grtz,
Arend.

DutchClutch

No one guys?

nom

There's a calculation around somewhere... I shall try to remember it I think standard fuel pressure is 3 bar at atmos? A guess would be 3.5 bar should see you fine (no calculations there!), at least it would be once a remap has been done

AndrewC

Some good info on injector size and effects of fuel pressure here.

Andrew...

DutchClutch

Thanx guys,this is the kind of info I was looking for.!


Reading the link-story,could anyone tell me what fuelpressure I need to get my 380cc-injectors perform like 440cc-ones?I run on 1.22something turboboost.

Grtz.
Arend.

cube

DC, according to the book Forced Induction Performance Tuning by A. Bell, a 380cc injector rated at 3 bar delivers approx 423 cc measured flow at 4 bar and 429 cc at 4.8 bar. The theorectical flow rates are 439 cc and 481 cc respectively, so you can see that efficiency drops off significantly as pressure is increased. This kind of increase in pressure may require uprated pipework as well. Probably safer and easier to just fit 440's and run at standard or slightly increased pressures.

Cube.

R19KET

It says that you have a '99, but have a "WRX" engine. Since you have Ecutek'd the car, I assume the WRX engine is also a '99/'00, or you swapped the heads/inlet manifold over, so that you could retain the '99 AIC. The '99/00 cars have 440cc injectors.

What turbo are you using ? If you still have the TD04, 97% IDC is very high for 1.22bar, and you may be running very rich.

Mark.

DutchClutch

Mark,

I got a Jap.import WRX(std.260BHP,MY96?) transplanted in my MY99-enginebay.
All my orig.MY99engine-stuff(actuators,generators,TD04turbo,IC,etc.) is used on this 'new' engine,excépt the 440cc-injectors,cause they didn't fit.So it runs with the 380cc Jap.injectors.
All is connected to my orig.MY99 ECU.

Brings me to the following question:

Does anyone of you know a bigger injector-alternative,that will fit the Jap.import WRX-block(MY96-std.260BHP),for a 'payable'amount of £££?

Arend.

cube

DC,

The 440's can be fitted with a set of adaptors. Do a search on here for 'Injectors'. Pavlo makes them up for about £30 a set.

Cube.

harvey

iTrader: (48)

You would be best to fit 440cc injectors and as Cube says Paul Blamire can sort out an adaptor kit. Increasing the fuel pressure is unlikely to increase fuel flow to a safe level for you on 380ccs. You require a 1:1 fuel regulator, not a rising rate. I can recommend SX from the USA. Some people use the FSE 1 : 1 which is cheaper but not designed to operate over 5 bar. I suggest you start by setting the FPR at 3.25 bar with the vacum/boost control line disconnected. What you need then is to check that your fuel pressure is always boost pressure + 3.25 bar. So at boost of say 1.2 bar you want to see 1.2 + 3.25 = 4.45 bar.

harvey

iTrader: (48)

Just to add that I have experience of 380s maxed out at 290bhp.
Paul may also have injectors if you have not got your original ones and if he cannot help then try Scotty who also posts on this board.