I have a 2003 S2k with a Vortech Supercharger kit. I am planning to use 440cc injectors and the AEM FPR. Or using an additional injector to keep it rich on top.

Does anyone know the stock injector size our car? 360cc?
Is the stock injector different from an pre 03 to an post 04?

Any success using 440cc with the vortech setup and the original split second box?

Calculated idle fuel pressure with 440s?
Stock ~ 42psi, with Walbro pump ~48psi.

Any problems on the A/F being lean on the top end?

Suggestions and advice with the setup?

Thanks.

 

I believe 360cc/min is what the stock's flow bench test at.

You're going to need something to control them, The stock PCM can't, neither can the timing controller.

The 04 Vortech now uses a Aux 5th injector. You may want to contact Vortech about a retrofit.

 

Why can't the stock PCM control the 440's? High, Low resistance compatability? Which one does our stock injectors have?

My kit actually came with the bung in the aftercooler for the extra injector. However, they did not give me the hardware to seal the extra injector hole. I'll try to contact Vortech to see if they can provide me a newer split second box to control the extra injector as well as the pieces needed to seal of the bung.

 

Because the PCM has no idea you changed the size of them.
The car will run so rich at idle with the 440's it will throw a fuel metering DTC within a few minutes. You have to use some means to "trick" the PCM with a Piggyback unit, or go with a standalone programable EMS.

An e-manage, or AEM EMS.

The 440's are high impedence injectors, if you had low impedence units, you would have to wire in a resistor pack.

 

I was planning to lower the fuel pressure to ~30psi to compensate for the 440cc injectors. With the help of an AEM 1:1 fuel pressure regulator.

What is the stock injector, low impedance or high?

Any other manufacturers that has 440s that can just plug into our current harness?

How bout the RC engineering 440s are they high or low impedance?

 

I'd contact RC before running the injectors at that low of a pressure.

Nobody makes direct drop-in/plug-in injectors for a S2k. You get to cut the connectors off the harness, and splice in new Bosch/OBDI connectors. You also get to install spacers under the fuel rail stands because the RC's are taller.

Stock injectors are high impedence, so are the 440's.

 

Thanks for your help.

 

I heard that our stock injectors will start to stick once fuel pressure is near 90psi is this common to all?

At what pressure was our injector tested at the flow bench to get 360cc/min? 43psi?

What was the tested pressure that our stock injectors started to stick at?
What is the repercussions of sticking injectors.

 

I don't have the Flow sheet, I'm not certain what pressure they where tested at. I believe 43 sounds about right from what I remember.

Having the injector stay stuck open is probably the biggest potential problem. A cylinder can fill with fuel and hydro-lock.

Running any injector over 80% duty cycle is asking for trouble. The pintle doesn't seat, and the spray patterns can get awful.

 

i ran the injectors on my dsm at 100% for a year or so before i sold it. it isn't good, but it will work for a while. (btw, no knock)

i'd say an appropriately sized injector would require about 80% of it's flow capacity. you don't want to pick an injector that's too big unless you are going standalone, otherwise you're going to be "lying" to the computer too much and reporting way too little airflow. this will advance your timing a great deal and possibly cause knock.

if you go with AEM or any other standalone you can tell the computer exactly what size injector you're running so you won't have to manipulate the airflow signal.