Modme

iTrader: (4)

Hi Everyone,

I've been doing a lot of research after purchasing my Vortech kit but I need a little help clearing things up. My plan is to run the stock 3.3 pulley as safely as possible on the stock block. I've heard a lot of things about the stock injectors being maxed out and could be problematic later on. That's why I decided to get 440cc. My question is what is the best way to run the 440s?

Options are:

1. 440cc using vortech FMU and inline fuel pump with SS box retune
2. 440cc with 255 walbro and SS box retune and ditch the FMU

Can the injectors handle the pressure from the 255 walbro or is a fuel return system very important?

Thanks!

Jason

BankyDori

They will work with the 255.... Thats what i have on mine, Vortech-255-440cc- and a utec... With a tune I got 338. Problem is my injectors were at about 95 percent duty cycle (so I was told) So I have been searching to find out if I have a Fuel pressure problem or a injector size problem lol. Im gonna yank the fuel pump out this weekend, just to make sure its in right cause im just about out of Ideas...

BankyDori

Not tryin to jack your thread! lol

Modme

iTrader: (4)

Is there any problem with the fuel pressure being too high during idle?

Car vs. Driver

iTrader: (14)

If you're asking if it's OK to run a walbro, then yes, that's fine. If not, you need to tell us how high your pressure is. Either way, with your setup I'm pretty sure you're fine.

I've said this a zillion times, and so have many others, 440 injectors are worthless in this car for FI. I'd recommend at least 550's to error on the side of caution.

The other thing about maxing your injectors that people don't often discuss is the fact that without a fuel return, you can't adjust your pressure to compensate for boost. The higher the pressure in the intake, the more force is needed to open the injectors and spray fuel, so you'll ALWAYS have a higher IDC without a fuel return (plus your fuel pressure will drop as the injectors max out and boost increases). You can bring your fuel pressure up to a reasonable level, drop IDC and have better control over fuel with a return setup and the same injectors.

And for what I'd recommend:
1. Ditch the FMU and SS box.
2. Get 550's, a walbro and a UTEC.
3. Add a fuel return if your budget permits. If not now, add one later

fpacquing

iTrader: (11)

with the 3.33 pulley just use option 1

booger

iTrader: (6)

If you are going to run the kit as out of the box . You will need to do squat....nodda...... nothing . Just get it tuned . The stock kit normally runs very rich up top . The tuner will reduce the injector duty cycle and maybe...maybe not , put some timing back in it .

tylerxfire

iTrader: (15)

u don't need bigger injectors if ur just gonna run stock pulley on a full vortech kit, u will be fine, just get a tune on the ss box is a good idea