Having ported ls6 heads, 224 581 114 cam, ls6 intake and ported throttle body installed on my 99 ... concerned that the fuel injectors are going to be to small... Do you think my concern is valid? If I go to SVO #30 will they just plug in and work okay? Won't the fuel tables need edited just to run? I have a Dyno tune scheduled about 2 -3 weeks after install, but would like the car to be drivable... also anybody have a part number on the SVO #30 injectors?

 

You don't need to go to the SVO 30# injectors. Any of the GM 28# injectors will supply enough fuel for that combo. The only ones that would be too small are the ones that I had stock, 26# pea shooters. :(

 

Your injectors are 26.2 lbs/hr at 58psi fuel pressure. The 1999's and 2000's had them, so I had them in my car. I was making 347.3 rwhp that translates to about 400 crank hp. I did an EFILive scan while getting into it in gears 1-4 and found my injector were going to 105%. So I bought a set of 28.8lbs/hr injectors and now they run to 95%. If you are going to make over 400 crank hp you should get 28.8lb/hr injectors. They should be good to about 445 crank hp. I think you are going to make around 450 at the crank if you have LT headers, free exhaust, and free airbox, like a blackwing. I would get the 30lb/hr. injectors. You will have to edit the IFR tables, but with that much change to the motor you should have it tuned with LS1Edit to optimize it. The 30lb/hr SVO's are rated 30lb/hr at 43 psi, so are more like 36lb/hr. And they should be good to over 500 crank hp. Check this site out to calculate your desired injector size. http://www.rceng.com/technical.htm#WORKSHEET Check out TSP for 30lb injectors. They have great prices and even offer flow-matched which is ia great thing to have going in. You don't want one injector lagging and go lean on one cylinder. That would cause liquid pistons. :shocked: When I go to a h/c setup I know I'll need bigger injectors.
:cheers:


[Modified by ArKay99, 8:22 PM 4/2/2004]

 

You dont really need to start thinking about the 30#ers until you get past 430rwhp or so. Even then, you can check the duty cycle of the injectors to see if you need new ones.

If you do change injectors, you need tuning at the same time.

 

I guess I need to upgrade to a larger injector! :eek: :shocked: :thumbs:

 

a a vette bud offered me his stock 28lbs... and I passed.. :banghead:

 

I would say you really do need #30 SVO injectors, and then you do need a tune to get the most out of your mods. You can get a fair number of HP just with injectors and and a good tune. http://www.thefordsource.com/store/m...rts/fuel_3.htm
Set of eight brand new $239 + shipping
or go to Ebay can get low mileage set from people that went bigger.
Jeffy'

 

:iagree: :yesnod:

 

You will need bigger injectors according to the accepted formula: (Injector Size lb/hr) x (Duty Cycle) / BSFC = FWHP rating per injector.

It is generally recommended that you keep the duty cycle to no more than 80% for reliable injector operation and longer life. Using the accepted Brake Specific Fuel Consumption Figure (BSFC) of .50 then you get the following:

97-98 = 28.4 lbs/hr
80% duty cycle rating: 45.44 FWHP x 8 = 363.52 FWHP
100% duty cycle rating: 56.8 FWHP x 8 = 454.4 FWHP

99-2000 = 26.4 lbs/hr
80% duty cycle rating: 42.24 FWHP x 8 = 337.92 FWHP
100% duty cycle rating: 52.8 FWHP x 8 = 422.4 FWHP

2001-up = 28.2 lbs/hr
80% duty cycle rating: 45.12 FWHP x 8 = 360.96 FWHP
100% duty cycle rating: 56.4 FWHP x 8 = 451.2 Crank HP

30 lbs/hr SVO = 36.12 lbs/hr (LS1 at 58psi)
80% duty cycle rating: 57.79 FWHP x 8 = 462.33 FWHP
100% duty cycle rating: 72.24 FWHP x 8 = 577.92 FWHP

Since you will need tuning, you should wait until then and you can check for sure what your duty cycle is and then change to the larger injectors. With your ported LS6 heads and the 224 581 114 cam, I doubt that the 2001-up injectors would be big enough. The SVO 30 injectors are also cheaper.

 

Get the SVO 30#. Similar setups run differently and have different fueling needs. If you need to change injectors, and you do, then get some you can grow with. Check my sig I have a similar setup and was 100% duty cycle at 6000 rpm with the stock 28.8 injectors. The SVO's are a good buy and have the same construction as stock. No need to change the injector offset table. Simply adjust the IFR table to get the desired part throttle LTFT's then PE vs. RPM for the desired WOT AFR. The installation is about 90 minutes. :chevy