Nitrous injection with EFI

Hey all,

I'm thinking about how to program the EFI when I add nitrous. I want to add the additional fuel by increasing the pulse width of the electronic fuel injectors (ECU will swap maps when nitrous is added). It seems to me the additional fuel injector pulse width should vary with engine rpm when adding the nitrous. The nitrous is being added a constant flow rate, but at different rpm the time of injection is different.

At 6000 rpm, one rev or "time of injection" is .01 sec (10 ms).
At 3000 rpm, one rev or "time of injection" is .02 sec (20 ms).

So at 3000 rpm aren't I going to have double the amount of nitrous going in the engine during one rev? Therefore, wouldn't I need double the additional pulse width from the fuel injector at lower rpm than I would at higher rpm?

I'm referring to additional pulse width beyond where my base map is right now.


Thanks,


Sean

 

Thanks Mark.


Right now my injector duty cycle is at 70% at close to 8000 rpm.

Fuel pressure is 35 psi . . . if I crank the fuel pressure up say 20 psi to 55 psi, how much should I be able to lean out the map . . .what's the equation for pressure vs. flow? Want to make sure I've got plenty of fuel capability the first time I dump in the nitrous.


So are you playing with nitrous?



Sean

 

Thanks for that info . .. yep .. . that would be a good reason to be banned!