Hello all, I have an issue that I hope I can get some help with, first I will list my build.
2007 Mustang GT
298 livernois stroker with stage 3 heads
ID 1000 injectors
Division X Return style fuel system (1200 horse)
D1SC Procharger with 800 horse stage 2 upgraded intercooler with a 3.400 pulley (20 PSI at 6500 RPM)
E85
Car made 650 to the wheel on the blower alone
Before the blower, the car was a nitrous build, and I still have the nitrous kit on the car, it had sat dormant for the last year as I played with the new blower. My kit consists of,
Custom Nitrous Outlet direct port, currently jetted for a 75 shot (18/10)
NX SAFE standalone fuel cell set at 50 PSI (Using E85 as well)
Now before the blower the kit was jetted for 200 shot and worked great for 2 years. I put hundreds of pound of nitrous thru the car with zero issues, of course that was N/A. The problem started the other day when I tried to spray the 75 shot on top of the blower.
Window switch is from 3500-6800 controled by a wotbox. I logged with just boost and everthing was fine, so I loaded my nitrous tune and hit it, It has a bad lean spot from 3500 to 5000 rpm.
The hit felt great, but i lost 1 or more plugs in the pull, I had to change out all 4 plugs on the drivers bank to get the car logging correctly after the pulls as it was showing bank 2 o2 sensor was not happy, I had a ton of unburnt oxygen in the charge. SO I just replaced all 4 plugs and the car is happy again...and I have not sprayed the car since.
Now i will say that the regulator was not boost referenced on the nitrous pulls. It is now, but it was not during my first test hits.
I called 2 reputable nitrous companys and asked them what they thought of me going lean.
Company 1 response
Fueling is always an issue to get correct when compounding nitrous with boost, suggest you up your fuel pressure and install your 200 horse fuel jets (16) and see what it does. He went on to say that a pressurized manifold will NOT affect jetting in a situation like this....
my thought is then why do I need to up my fuel jets?? Not happy with this response I called Nitrous company 2
Company 2 response.
Boost reference your stand alone fuel regulator...done! Manifold pressure DOES affect jetting so if you have 50 PSI fuel pressure and manifold pressure is 20, you are only delivering 30 PSI of fuel pressure into the stream.
This theory makes more sense to me, but I would like to hear form some guys in here that have real world experience wit this.
As my car sits, I'm still jetted for 75 and i have increased my fuel pressure to 63 and have boost referenced the regulator. I want to go make a test hit but am going to wait until I read some replies in here before I do...
Am i putting too much science into this? Does manifold pressure play a part in jetting?
Thanks for any input anyone can share.
Engine
Nitrous Kit
Bench testing fuel jets. .010 jets at 50 PSI.
http://vid864.photobucket.com/albums/ab ... duuzqm.mp4