Hey guys need some help with my g35 coupe. Have a Vortech v3 supercharger on my car. 1200 injectors, 450 fuel pump . Issue I’m having is that under load (in gear) after about 4-5k rpm car stutters and doesn’t want to go past it. Another thing is if I rev the car over 3-4k on neutral or even on gear as soon as I let go off gas car goes under 500 rpm’s and occasionally will stall. Checked for vacuum leaks with smoke test no leaks at all. Checked for exhaust leaks no leaks. No CEL lights on. Any suggestions, thank you

 

Those injectors are huge. What's your AFR at the times where you are having issues?

 

Gonna need more info. What are you using to tune the car, UpRev? Stand alone? Sounds like either too much fuel or not enough fuel. What plugs are you using, and what's the gap? Is that 450 pump running off the stock wiring or did you run a 10ga wire and a new relay?

 

yes I’m running a relay kit with thicker wiring. And I’m on a conservative tune right now with uprev. I’m using the 2 step colder spark plugs along with the z1 high energy coil packs. Everything is fine with those.

 

I have not checked that yet but af gauges normally sits around 13-17. I know I don’t have a exhaust or vacuum leak since I already did a smoke test and it’s all good.

 

I do want to add that with my logs I notice that ignition timing can go from 15 to as high as 40 and even as low as -5 depending if I’m on idle stepping on it or when I let go off gas. I am still not pushing boost. So this issues gots me stuck

 

13-17 is very lean under boost! Get a new tune. You're going to ruin that motor

 

At idle, or load? Should be 11.5 to 11.7 under load WOT.

 

What mass airflow sensor are you using?

I wonder if youre exceeding the limits of the OEM MAF w/o a resistor or aftermarket / rescaled MAF.


13:1 is fine for low load and low RPMs, 17:1 is fine for idle
10:1 to 12:1 for boost

 

I’m not running boost yet. I’m on a conservative tune still. Trying to get the car right before hitting boost

 

13-17 on idle

 

sorry forgot to add that on my original post. I don’t have the OEM one , I’m running the uprev maf sensor

 

Is it safe to assume that you’ve rescaled yoru MAF sensor accordingly?

What have you done in the tune to get the car started and up & running?

 

I just got it flashed to get running , everything is relearned.

 

Did you modify your K-Value (I believe) for the Uprev MAF Sensor?