Spent this week going over my nitrous system logs. I built my very own system with some unique differences from other nitrous systems that are out there. My system is a direct port injection dry system that is designed to work with turbo and supercharged engines. It has a 'phase change' vapor chamber but still runs at subcritical pressures for consistent nitrous flow. Pics below, first pic is a run without nitrous, second with my nitrous system enabled. Around .43 seconds faster via "Dragy" with nitrous with the same ignition timing, fuel flow and manifold pressure. This would be around a dry 50 shot by industries standards.
A couple other take aways from this post. These runs were done in open loop, so the injectors had the same opening times using the same map. This is why there is a 11.7 A/F ratio with no nitrous vs a 12.7 A/F ratio with nitrous. So, if I would have added more fuel to get a 11.7 A/F ratio the nitrous pass would have definitely been faster with nitrous and fuel vs nitrous only. So, some of you might be asking why I did a nitrous vs no nitrous test and run the engine lean on the nitrous pass knowing it would be faster with fuel being added??? In short, I was testing combustion flame speed. I took what I learned from testing my stratified charge lean burn system. When I run my engine at light load and lean burn at 30:1 to 35:1 A/F the flame speed is very slow due to the extreme lean condition. So. I did some testing with nitrous to increase the flame speed and it work amazing. The amount of nitrous that was used with this test was pretty much next to nothing. Pretty much a small nitrous leak amount that I'm talking about. To achieve my 45mpg all the engine needed to make is anywhere from 10whp to 18whp at light load freeway speed. Now back to the performance side of things. I'm running GEM42 fuel that is made up of 91 pump gasoline, E98 ethanol, and Methanol. The alcohols make up most of the GEM fuel. This fuel is great with knock but has a very poor combustion flame speed. So, this is why I did all this testing with nitrous to see how much it would benefit by only using a very small amount to promote flame propagation. So far, the results are great. I have parts per hour PPH of nitrous flow, but I'll get back to that at a later time. PPH flow will be determine mainly by bore size and of course volume of the engine. One last thing is on this system I want nitrous vapor only, but that is another book in its entirety.