I’ve done a reasonable amount of normally aspirated and forced induction work in my lifetime but have yet to do anything with nitrous. This is why I’ve asked what are undoubtedly very basic questions on other threads.

I am a nerd and, as such, something Ray said in one of his responses has been rattling around in my head. To paraphrase, he said told me I’ve already done boosted work and nitrous is not really that different. Both provide more oxygen in the combustion chamber and thus both require more fuel and, when the charge densities get higher, less timing. That makes more than perfect sense. Now on to the nerd part-

To do forced induction on the stock PCM, you basically increase the load axis to accommodate higher than normally aspirated loads (above say 110%). When the MAF exceeds NA levels for any particular rpm, you enter a “boosted” portion of your fuel and timing maps and you can compensate with richer mixtures and less timing if you like.

Apply the above to nitrous……
I love to build widgets and was thinking about a widget (about 1” X 3”) that would live between the MAF sensor and the wiring harness. Get the right connectors and it would simply plug in place. This widget would be programmed to kick on one (or two or three) nitrous solenoid(s) at a programmed point (wide open throttle above a certain rpm and above a certain coolant temperature and ….). At the same time, it would add to the MAF being reported to the stock PCM pushing the system into a non-NA regime where you could handle fuel and timing.

A supercharged engine is good for 300 hp to the wheels on the stock fuel system. Take away the 40ish hp load of the blower and you are talking 340 hp to the rear wheels. In theory, you could provide 340-180 or 160 hp worth of nitrous and still not exceed the stock fuel system’s capability.

The neat part about this is that the nitrous is a dry system. There is no splicing into the stock fuel system for a fuel solenoid and jet. There is no nitrous fuel system pooling in the intake manifold because the stock fuel injectors are providing the fuel. You get timing and fuel set exactly where you want it with no piggy back devices (apart from the MAF widget). Lastly, the car works in the NA realm exactly as it always has. You can even pull the widget and nitrous bottle and leave the flash in place as the car will never see the boosted load levels and thus no one would ever know it was not a stock flash.

Just a thought that I wanted to run up the flag pole……

 

i dont know much but we all own wet kits bummer

 

This is going to be an exciting summer....there are a lot of doors opening wit the flash tuners that were closed before by our less than co-operative OEM PCM

 

Umm.. forgive me for playing Captain Obvious, but the "MAF widget" you are talking about is a piggyback. You can do this with the greddy EM[U], canzoomer, etc.. I don't see why you would need to create a separate box..

There's also a pretty good chance it wouldn't work very well, since adding 160hp worth of nitrous would be loads close to 200%, which would likely make the PCM freak out. You don't get timing and fuel "exactly where you want it", you get it where the PCM wants it for a specific engine load... If the good folks at Mazda never imagined the naturally aspirated engine would see a VE of 200 or so (a safe bet IMHO), you can get in alot of trouble that way. Better get something where you have direct control over the fuel / timing.

A dry system is not a bad idea, however.. You might have to upgrade injectors, but as you mentioned the fuel pump itself is good for pretty high power levels... (And BTW, changing the fuel injectors also requires a piggyback box of some sort, so you're SOL either way)

 

i think you missed what he said here

"you basically increase the load axis to accommodate higher than normally aspirated loads (above say 110%). When the MAF exceeds NA levels for any particular rpm, you enter a “boosted” portion of your fuel and timing maps and you can compensate with richer mixtures and less timing if you like."

hes talking about flashing different maps into the PCM with the widget as a trigger for the PCM to move to those maps. sort of like and closed/open loop idea but instead a "no juice/juiced" flash.

why he thinks we need a MAF fooler i don't know. We dont need to trick the PCM into the right portion of the map. We need the Juice to flow when we get to that part of the MAP. Use the VFAD vacuum for the trigger. You go wot you get juice

changing the injectors requires no piggy back at all- just proper tuning of the PCM thru a flash.


edit: oh i see Lola is saying use the MAF fooler so that you can basically have an NA flash and a Nitrous flash all in one. without the nitrous and widget installed the PCM would just run the standard NA mapping but with the nitrous and widget installed you could trigger the PCM to use a set of maps it would never get to NA

 

Sorry, I got a "Jump to Conclusions Mat" for Christmas... If you reflash the PCM with a new map, this makes a little bit more sense. You simply need to "add" a certain value to the MAF reading when the juice is on, and compensate with a proper map in the PCM

 

My bad on not spelling out the PCM reflash too.

As for capacity, my logic went like this-

300hp supercharged without running completely out of injector duty cycle. That’s 120ish over stock to the rear wheels. Remove the SC load and get maybe another 40ish for 340 hp to the rear wheels. This SHOULD be exactly the same as the SC stuff and thus hit 155ish on load. I say should because all this thread was doing was running an idea up the flagpole. I've not done it and am not all that sure that there is a good reason to go try; especially with all of Ray's good work going on.

and yes, it would be another piggy back idea.

 

I’m taking a small break from the forum. Please PM me if I can be of any service.

Tks, Lola