Hello, I will be getting the greddy 18g kit, and swapping the emanage for a Utec. I was planning on using the stock fuel system with a walbro and larger injectors, (as I heard the 440cc RC injectors that come with the kit MAY be nearly maxed out at the power im trying to achieve, which is ~400rwhp).

Few questions:

Firstly, can I even use the 600cc DW injectors successfully with the stock fuel system or are they too big?

Will I need need to modify the stock fuel pressure regulator for the walbro? Can it handle the pressure that the walbro puts out?

 

400 on a stock motor is no problem with the stock greddy injectors. 600cc is boarder line with a utec as far as hot and cold starts. You may have to floor the gas pedal when starting the car.

 

Walbro install, gotta modify a few things but should be ok with stock FPR I believe? : http://cj-motorsports.com/342install.htm

My 600cc DW's hot/cold start flawlessly with my UTEC, been boosted for 2.5 years

 

I ran RC 650's with my old stock setup no problem with my walbro set up via phunks DIY...ideally you would have a fuel return, but I had no issues with it...

 

DW600cc Injectors, Walbro fuel pump, plus fuel pump assembly modifications should get you safe stock block power with a UTEC. 400-450whp max depending on the dyno. Of course, for max safety do a basic return.

 

Thanks for the replies, guys!

With all of our larger injectors we do recommend that you upgrade your fuel pump, just to ensure that your engine is getting the fuel it needs.

TW, if your goal is 400-450whp, the 600cc's would be perfect, right around 80% IDC, too!

Chris

 

Awsome thanks guys

 

I have 600's with about low 30's in fuel pressure(at idle with vacuum applied) and 1:1 afpr, using emanage ultimate. Walbro 255. No issues.

At what fuel pressure would that be, just out of curiosity.

 

Noob question- what is the fuel return used for?

 

It allows unused fuel during idle/cruising conditions to return back to the tank, instead of dead-heading at the fuel rail. It also allows you to use a fuel pressure regulator to regulate the desired base fuel pressure at idle and increase pressure at a 1:1 ratio with boost.

 

43.5psi is what all of our flow rates are based on.

 

Here's a slightly off topic question. Would you be able to use a walbro fuel pump with the stock injectors/fuel system? I am considering removing my procharger and going back to stock.

 

You should be okay if the FPR is in good order, however, if the FPR can't handle it you'll see a little higher pressure because of the pump and your gas mileage will suffer a bit.