Have a 2003 Z with Vortech Kit, 12lbs Boost, 2.87 pulley, headers, no cats, full exhaust, stock Vortech fuel system with a 6 to 1 FMU (8 to 1 stock) and 400cc Deatschwerks injectors. has been running fine for 12,000 plus miles this way. (or so I thought)

My question was about Fuel Supply. I thought I might be maxing out the injectors.I verifyed injector DC today and I was right. IDC is at 95% @ 6300 rpm. I will be raising the rev limiter to 7100, but need proper fuel supply before I do so. I talked to Mike @ Deatschwerks today, we thought that 600cc injectors and removing the FMU and keep the Vortech in-line pump may work, but he thought I should talk with you first. Any Thoughts?

Also the 440cc Deatschwerks injectors I bought over 2 years ago were rated @3.5 bars back then, so they really are about 400cc @ 3 bars. (always thought they were 440cc)

Also using Splitsecond box for tuning and do not want to change it out. It starts hot or cold great, and Idles perfect with the 400cc, will I be able to do this with bigger injectors? I do not want a bad Idle or hard starts.

I driven my car with this setup for 12,000 miles plus 20,000 miles with 3.12 pulley, so I want to change as little as possible, but make it right.

Thanks
Tim

 

I would just add a walbro intank pump and u should be good.

 

After some Thought this is what a think I should do.

1. 600cc/min @ 43psi Deatschwerks Injectors
2. Modify FMU to a 3/1 lbs/boost
3. Reflash ECU for 600cc injectors

Vortech Max-Flow 500 inline pump flows 190LPH@65PSI and 40GPH@90PSI p/n 8F001-500 Fuel requirements will be about 150-165LPH @ 7000rpm and 13PSI
Newer 350z Vortech systems came with a less substanial pump.

PRO'S please give your Thoughts.

Thanks

 

honestly i did not want to take a chance with a possible FMU or AUX fuel pump failure on my vortech kit, and also i knew in the near future i was going to step the power level up soon after i installed my kit. i went with the 255lph in tank fuel pump, CJM stage 1 fuel return system, 550 injectors and utech. i feel alot more at ease with this fuel system installed and it also is a good solid foundation for future upgrading. this setup has been proven over the years with the z33/vq platform.