Anyone running the two injectors larger than a 720cc?
If so what size and pros and cons.

I had the injectors rebuilt when the motor was rebuilt. The injectors are flowing 703 and 704 cc's. The motor (mild streetport) has series 4 rotors and housings with a lightweight flywheel and centerforce clutch. I knoe this motor can take more fuel but not sure as to how much more.
Any help would be good.

 

I think you would want to up the PSI not the size, as idle and low speed will be affected by larger injectors. having and RPM switch to kick on high PSI would work, but the change over might bog, studder.....

 

I can tell you that I'm running 800's or 820's, but I can't comment on how they work because I bought it like that. I have a major afterburn problem but also no air pump...

Mine is ported and has custom headers and exhaust. It moves really good but is like twice as fast at sea level. I expect it always runs too rich and the extra air pressure brings the ratio back in line to account for the drastic change in power that I experienced with the altitude change. From what I've been told the ECU is not smart enough to compensate for the larger injectors so really it will always run rich. Also I'm told that the AFM is now the bottleneck on air. So... I may very well buy a megasquirt CPU which would allow me to remove the AFM as well as map my own air/fuel ratio. That's about the extent of my knowledge so far...

 

Actually idling is not a problem at all, though I do have idle problems I'm sure they're not related to the injectors.

 

Thanks for the info there.
Mine also has no emissions crap on it, no rasts nest, and has the full Racing Beat streetport exhaust with the 02 bung and 6th port provision.
I runs good but was thinking if I could get up to 800cc or close to it that i would make more power.
I also am using the s4 intake so I am getting a little bit more air but my Air meter is still the stock GSL-SE.

 

With no air pump do you have afterburn issues? If not I can tell you to look forward to that if you do go with bigger injectors... If I accelerate through second and then let off the gas and have the engine holding back the car as it decellerates it'll pop pretty loud. The more power on acceleration the worse it fires and it can sound like a gunshot if I let it. People have said that it's unburned fuel lighting in the pipes and they're probably right.

Without something like a megasquirt to control the flow I personally wouldn't recommend it...