Playing with Jet sizes for better AFR's?
I do not know who is giving you tuning advice but you need to seek it somewhere else.
You have the wrong spark plugs at the wrong gap. Wrong jetting for the power level you are wanting. No clue where your timing is etc. This is recipe for disaster.
The Zex single nozzle system will not even flow enough nitrous to support the .083 jet you have in it.
For the system to support a 175 hp you will need to call us and order a new fitting for the FMU box as well as an upgraded hose that goes from the box to the nozzle.
The jetting you need to start tuning with at 175 hp will be .073 Nitrous and .041 Fuel at 45 psi. There is a possibility you will end up with less fuel pill during tuning. Matbe a .038 or .035.
The plugs you need are a NGK BR7EF gaped at .034.
Assuming your N/A timing is correct you need to be removing around 7-9 degrees of timing.
At this power level if you have not upgraded the stock LT1 fuel pump I would suggest investing into a racetronix fuel system system.
Dave
I honestly dont know why you have to run a 250 shot jet. Just do 150 shot and you will be fine with good tuning and a/f if you need to can play with it with jets. The only way I would run a 250 shot is with better clutch, tranny, different plugs with correct gap, fuel pump atleast, different solenoid and excellent tune to say the least. Even all that doesnt gaurantee anything. Goodluck OP
