Nitrous Stumble
Thread Starter
Racer
Joined: May 2012
Posts: 284
Likes: 4
Nitrous Stumble
We finally got my car strapped up on the dyno for a final tune and nitrous tuning.
I have the kit pilled for a 150. It picked up around right at 120 to the tire. It is fat on the hit and leans up at peak power. My kit is armed at 3300 rpm off at 6500, immediately on the hit there is a split second what seems to be stumble, almost as fast as it happens it clears up and pulls like crazy. The the initial afr on the hit is rich(iirc 11:1 up to 12.2 at peak).
It doesnt matter if I purge it or not. I will verify the afr's. The video below if not my car, but at the 9 second mark where he comes on the kit, you can see the car fall and pick right back up. This is near identical to what mine is doing. If it is normal I will leave it alone, however I do not think it is.
http://www.youtube.com/watch?feature...&v=xP8VMGIxXUQ
Nitrous Setup:
-4an feed line
Big NX Solenoids
Twin NX Shark Nozzles
.41 and .22 per nozzle
58psi Fuel Pressure
950psi on the bottle gauge
If you need any other info I will do my best to answer.
I figured you guys can point me in the right direction.
I have the kit pilled for a 150. It picked up around right at 120 to the tire. It is fat on the hit and leans up at peak power. My kit is armed at 3300 rpm off at 6500, immediately on the hit there is a split second what seems to be stumble, almost as fast as it happens it clears up and pulls like crazy. The the initial afr on the hit is rich(iirc 11:1 up to 12.2 at peak).
It doesnt matter if I purge it or not. I will verify the afr's. The video below if not my car, but at the 9 second mark where he comes on the kit, you can see the car fall and pick right back up. This is near identical to what mine is doing. If it is normal I will leave it alone, however I do not think it is.
http://www.youtube.com/watch?feature...&v=xP8VMGIxXUQ
Nitrous Setup:
-4an feed line
Big NX Solenoids
Twin NX Shark Nozzles
.41 and .22 per nozzle
58psi Fuel Pressure
950psi on the bottle gauge
If you need any other info I will do my best to answer.
I figured you guys can point me in the right direction.
Drifting
Joined: Oct 2004
Posts: 1,621
Likes: 6
Measure bottle pressure at the rail, not the bottle. It can drop up to 100 psi through the system. How are you running your fuel? off the rail? Is your fuel pressure staying consistent through the pull? where and how are you mounting your bottle? I know on the dyno orientation doesnt matter but on the street errrr track I mount it facing forward, it was a night and day difference in the hit. There is also a calculation for a how much spray you use in 10 sec through your nozzle you a can check to see if your flow is there.
Pro
Joined: Nov 2004
Posts: 645
Likes: 12
From: Hermosa Beach CA
You running a fuel pressure safety switch? When I used to run a dry shot on my SS this always caused problems with clean hits. I removed it and the problem was gone. Instead I relied on a a/f ratio gauge set up to toggle both banks.
