Purging N2O through the motor?

[Outsider]

I'm installing an N2O system and I am trying to avoid an extra dedicated purge solenoid and line for cost and stealth reasons, and I don't much like dumping N2O into the atmosphere anyway.

What are the possible consequences of purging the system by triggering it at less than WOT and at low rpm, feeding the N2O vapor/air through the engine, loaded and unloaded?

I'm guessing that I could just activate the system normally and it would bog with the excess fuel, correct? Any issues with doing that? What is the "correct" procedure for doing so?

 

[Alky V6]

Purging into the engine will be just like opening the throttle. If the hit is low enough, and I mean real low, you could be OK. What size shot are you talking about? Where are you injecting it? Before the throttle? If so, how far.

 

[Outsider]

1) Size? Nominally, 50HP, to start. Too much to purge through the motor?

2) Open to suggestion as to where to put the nozzle but atm in the back/underside of the (stock) riser pipe off the intercooler to the TB, close to either of the hoses joining the pipe to the IC or TB. Current preference is closer to the IC end.

 

[Alky V6]

Where are you injecting the extra fuel?

I would try not to purge into the engine. Not a good idea.

 

[Chuck Leeper]

Wow!!!

A good way to see if the intake is on tight, and the gaskets are holding.

 

[Grumpy]

A good way to see if the intake is on tight, and the gaskets are holding.

ahhhh the good ol days with the Mustangs to !!! They did put on a good show between the fires and explosions

 

[Alky V6]

A fellow racer has an early Cobra Mustang with a SB Ford. He runs a 250hp shot on it. At car shows, to impress the crowd, he momentarily activates the nitrous system as he blips the throttle. It revs incredibly quick. Not as quick as a Top Fueler, but pretty close. I wouldn't recommend it though. If a solenoid stuck, it could be real nasty.

 

[bobc455]

As long as you are using a wet system, it's okay.

Bring the RPMs to about 2500 (in neutral obviously) and hit the button. The revs should take off to 4-5k (once the liquid nitrous hits), and you gotta be careful to make sure the turbo doesn't start to spool. You can tell when the liquid is through because when you hit the button the revs will take off very quickly.

This is the only way I purge the nitrous on my big block, into the motor.

-BC

 

[Outsider]

Hmmm. Obviously it does work sometimes.

How about using a momentary type switch to bypass the WOT switch and window switch to allow purging with the throttle closed. I can build some (pretty simple) electronics to limit/set the "on" time of the system using such a switch. While I don't expect anyone to have done that (maybe?), any thoughts?

It is "dry" in the sense that the extra fuel will be through the gas injectors, rather than through a separate fuel solenoid and jet. Greater pulse width (ECM adjustable) provides the fuel and it's (evidently) not the NOS or ZEX style fuel pressure regulator "bump".

I can delay or advance the additional injector pulse width relative to the N2O switch on, to match the transit time between the point of N2O injection and the injectors too.

Any thoughts on using a temp. sensor in front of the N2O nozzle to adjust the amount of extra fuel added while purging?

 

[bobc455]

It is "dry" in the sense that the extra fuel will be through the gas injectors, rather than through a separate fuel solenoid and jet.

Then I'd recommend against it.

-Bob C.