Ian Carr

as the topic says whats the maximum fuel flow for stock injectors on a 86' 944 turbo?

-Ian

PCinDC

IIRC they are 36 lb/hr

I could be wrong, someone else will confirm/refute.

Sam Lin

Depends on the fuel pressure you're using. Crank up the pressure and have a pump that can deliver volume at that pressure and you can get as much fuel as you'd ever need.

Sam

Mike1982

Ok, so maybe I am getting this wrong but, if you turn up the pressure with the same fuel pump, you get LESS fuel but can get more power because of better seperation of the fuel molecules??..

Ian Carr

thats what the plan is we are just wondering what the maximum is so we know weather or weather not to upgrade them to a higher flowing injector

-Ian

Ian Carr

No, The fuel pump will always be able to put out more presure. You have a regulator to control the presure and you get more power by regulating more presure onto the injectors, which puts more fuel into the cylinder. This can also take away power because you can run to rich that why you supply the right amount of air to match the amount of fuel

-Ian

special tool

Watch that one Turbox.
With stock injectors and stock pump, you will get max. 300 RWHP.
As you turn up the pressure with all stock, the pump has to flow more, and won't flow enough, regardless of pressure to make more than about 300 RWHP.
If you buy a stronger pump and keep stock injectors, you can run higher pressure across the injectors and a bigger pump will keep up.

Ian Carr

Yeah I was not sure to what power it can suply enough fuel but for what i'm doing the stock fuel pump will work

OT: any one know what the highest Bar the stock pump can do? Or the most it can flow?

Also OT: Special Tool: I wanted to ask you if you had the timeing belt tenshioning tool? Also the shop that has my motor is Carlquist Competition Engines You may know where and what that is.

zerMATT951

<bump>

I'm also curious to know what bar the stock fuel pump maxes out at. I'm looking at adding 55# injectors with the 3.0 bar FPR and would like to know if I will need to upgrade the pump too.

Also, in case I decide to do more "stuff" and need bigger injectors later, at what point will I exceed the 3.0 bar FPR?

Thanks!

Edit: Nevermind - I found my answer after searching a little deeper... there was a thread last month that answered this (max pressure, stock fuel pump). Sorry about that

theedge

IIRC the stock is 2.5 bar.

Danno

Don't forget that there are standards for the injector-flow measurements. These are:

3-bar fuel-pressure
100% duty-cycle

And the measured volume is how injector's flow-rate is determined. Here's an article where I finally figured out the actual flow rates of the stock injectors: WTK- Injector requirements for 400rwhp.

Also don't forget that raising the fuel-pressure that a pump has to deliver will reduce its total flow volume as well. At stock 2.5-bar, the pump can deliver enough fuel for about 350-370rwhp. At 3.0-bar, it's about 325-350rwhp. Using insane 50psi that some people try in a futile attempt at squeezing more out of stock injectors will have the pump only deliver enough fuel for 280-290rwhp. You must also program the fuel-maps appropriately to the pressure as well.

HIGHBOOST

CAn't your stock injectors also jam up or something if you make them work too hard? ie: turbing up the fp too much?

Zero10

You can burn the coils inside them if you turn the pressure up too much.