If you plan on running 150+ on the highway or empty city streets, don't buy a 7, you'll kill it and yourself.

Nitrous is immediate gratification, it does the job NOW, and may not cost as much. Turbo, on the other hand, is a long term solution. It never needs to be refilled and a spooling turbo is so sexy. You could put nitrous on your Caprice, if you wanted, but that's never the smart thing to do. Find a 13BT and drivetrain, and then work off of that, building and spraying...

 

Any performance modification will!

It why turbo RX-7's don't last as long as NA! (Usually)

:O!!!!!

 

Agreed. The glorious sound of a turbo winding up on a high performance engine gives me goose bumps. Especially when you're in the car, and the Hand of God proceeds to flatten you into your seat.

-=Russ=-

 

*sigh*
Why is it that people post when they have no actual first hand information on the subject?

Ted aside, has anyone in this thread actually used a nitrous shot above 150 hp?

If not, how can you possibly comment on what is required to run such levels, what damage it does to the internals, how expensive it is, and how fast it will make the car?



Seriously... what's with all these threads on nitrous regurgitating an article I wrote 4 years ago? Anyone competant in using the search function can easily find it. As it stands now, I think that article sucks, and needs harsh revision. It should not be used for setting up or tuning any nitrous installation, its merely a crappy introduction to nitrous oxide fundamentals.
I have been meaning to rewrite it, adding content, my extremely comprehensive list of working jettings at given fuel and nitrous pressures, altering the timing under nitrous, and pictures..... but this trakes time, which just doesn;t seem to be in abundance right now. I think I'll tackle it over Christmas when I throw a system in my girlfriends car.


I'll post some more meat on this subject a little later tonight.

 

Another reason why that article sucks.

At the time of writing that article, at the age of 19, my only experience with dry nitrous was with an electronic system that upped the injector duty cycle under nitrous injection, much like an S-AFC. I hated the concept, despite how tunable it was.

Most dry systems now run what is called a FMU- fuel management unit. This is just a fancy word for a secondary fuel pressure regulator; under nitrous injection, it increases the fuel pressure in the fuel rails. With higher pressures, more fuel is injected for the same amount of injector cycle.
No over-running the duty cycle of the injecxtors, so no problems, right?

Not exactly.

When we up the fuel pressure, we do two bad things: we lower the fuel pump flow (the higher the pressure, the lower the pump flow), and we alter our fuel atomization. There is a reason most factory and aftermarket fuel injection systems choose to run a pressure differential of 40 psi: any less, and you get crappy fuel atomization (fuel dribbles out of the injector), and any more, and the fuel just ends up spraying onto the opposing runner wall.
So, with a dry kit running an FMU: we up the rail pressure, and with the stock FC's 90's degree injector set-up, we end up spraying fuel directly onto the intake runners. This can easily result in nitrous backfire.
This is why I think people have so many problems with ZEX kits on their FC's... up the fuel pressure, lower the fuel pump output and detonate if they don't nitrous backfire first and destroy their intake manifold.


So, yes, wet is still the best way to go... but for different reasons.

 

Ah.

My experience with nitrous is just up to 150 shot and the like. Never on a rotary. Just lowly 4-cylinders and pushrod v8s .

 

I read the article, and it's a good primer, but I feel it's a little bit aggressive in the ignition timing department.

Have you ever dyno'd the car with the ~200 shots of NOS on?


-Ted

 

That car was long since sold. I no longer even own an FC. I own several engines for them, including a PP project I built a few years ago and never actually got around to installing in a car.

I have been there for the dyno's of other cars that I have set-up and made some timing/jetting changes between runs on 200 and upwards nitrous shots.

I gotta say... its pretty messed up dyno graphs to see a N/A engine jump from around 100 to over 300 hp instantly. Spike looks like it was when the engine went WOT.

When I build another street car for myself, it will be using a turbo engine. May or may not throw a shot onto it... depends on how well I size my turbo I guess. Too much needs to be changed on the 6 port cars to bother using big shots of nitrous. The drivetrain just cannot support it.