Nitrous/fuel issue need help

[07graygt]

Hey guys, I have a 2007 gt. I was at the dyno today getting tuned for 150 shot. The tuner said that when the nitrous hits fuel pressure is dropping down to ten psi. But then it comes back up. He is concerned with detonation when it drops to 10psi. Mods are nitrous outlet plate kit 150 shot. Not sure what the jets are but is the ones recommend. Hot rod cams, long tube headers, frpp intake manifold and throttle body, roush intake, 39lb injections and walbro 400lph fuel pump. He is not sure what's going on with that big of a drop in fuel pressure. I have a track day next Saturday and I'm hoping to get it right by then.

 

[07graygt]

Bump.

 

[drive_55_not]

You should have 63 nitrous and 35 fuel jets, A 35 jet isn't pulling that much fuel off the rail.

Is your fuel pump voltage staying 13+ volts when the solenoids activate?



.

 

[07graygt]

I'm pretty sure those ar the jets I'm using. Not sure on the voltage I didn't get to see the data logs or anything. Just the fuel map on the hp print out.

 

[702GT]

You should have 63 nitrous and 35 fuel jets, A 35 jet isn't pulling that much fuel off the rail.

Is your fuel pump voltage staying 13+ volts when the solenoids activate?



.

It doesnt pull a lot of volume but it does bleed pressure. The momentary loss in pressure is recovered fast when the frps tells the pump to turn it up a notch.

If you want to avoid pressure loss, use a return system or dedicated fuel system. Its not a big deal to set one up and you can run race gas in it just for the shot giving an extra bump in octane against detonation. On a returnless system there will always be a momentary drop in pressure. Bigger the pill, bigger the drop obviously.