[chiphead]

So I was running a sniper spreadbore plate under a Q-jet on my old motor. During the engine rebuild, I replaced the stock solenoids that come with the kit with higher quality solenoids from nitrous outlet. The orifices on the new solenoids are larger than the stock solenoids. The stock sniper solenoids are entry-level and I didn't want to risk an engine due to a bad solenoid.

Do larger solenoids affect the tune-up, if the jets are much smaller than the solenoid orifices? I'm only going to be running it at 100 to 150 HP levels.

Will the online calculators for jet maps still be accurate? Or do I need to spend the coin to send the system out to have it flow tested and re-mapped?

[chiphead]

Let me ask this another way: What is current thinking with jet maps? Is the fuel jet supposed to be same size or smaller than the nitrous jet? The old tune ups called for the fuel jet to be larger than the nitrous jet. But the online calcs call for the fuel to be 3-8 jets smaller than nitrous jet for a given power level. I had a 8 jet stagger, but on teardown I had some detonation on the rod bearings. Pistons looked great. But something was amiss because the bearings looked hurt.

What is current thinking about safe starting point? My new motor is totally different so I'm back to square one.

[charlie66]

I use the Holley cheater system. They come squared . Which results in being rich but safe. From there, reading the plugs you can incrementally go down on the jet .. Also you can flow the jet with less psi to lean up things as well. They say 5 psi with mine....