98AcuraCLpimp

im just curoius as to have many miles you would get to a pound of juice? also for those with nitrous how nong do you run it at a time? is it bad to run it for long periods?

Cocoa

iTrader: (2)

mm...not sure if I get it, but assuming as to I know what your talking about, hear are my responses.

For a 10 lb. bottle you'll get approximately 5 min. of squeezing (using the nos) if you were use it non stop.

And as for how long you can use it: Well never squeeze for longer than 15secs at a time, otherwise you can say goodbye to your motor.

This is all that I have read/heard about it. I'm pretty sure my info is pretty accurate, but if not, someone else will correct me soon. Hope this gives you an idea of what to expect and what not.

rebeltruce

Cocoa is right on the money, 3-5 minutes non-stop. I've never sprayed for longer then 15 or 20 seconds. I can't afford a new motor!!

Nashua_Night_Hawk

best to do is have a 100% throtle activation switch, with rpm windows protection... like, Once Enabled, I would like to activate Nitrous betweem 3900 rpms and cut off at 6900 rpms.

I do not expect you can keep 100% for more than 20 sec unless you would like to reach 140 MPH!

So what Nitrous kit does that?

Nashua.

lnsyone

yeah, if you were to get a nitrous kit, id invest in an rpm window activator switch- like what he had mentioned above. sure, its kind of expensive, but its cheaper than rebuilding a blown motor.

fastvtecCL

very smart

rebeltruce

The ZEX kit, that most of the folks on the board have only activates at WOT. Doesn't have a RPM based shut down switch though, but that's an excellent idea.

Nashua_Night_Hawk

excellent info here: http://www.go-fast.org/z28/new_to_nitrous.html

some info:
What Can Go Wrong?
Well, a lot can go wrong, but hopefully you'll have adequate safety mechanisms built in to protect your motor when it does. The main thing that can go wrong is adding nitrous into your engine without compensating fuel. This extreme lean condition is disaster for the engine, and you're not likely to get a second chance - at least with the same engine. Conversely, adding extra fuel without nitrous is not particularly bad for the engine, so you can imagine, it's safer to start with the car running rich (too much fuel), then lean it back from there. Some examples of problems you might encounter include:

Fuel pump fails A failed pump will lose pressure immediately, causing an extreme lean condition
Fuel injector failure or lockup Using stock fuel injectors with a dry nitrous kit can cause the injectors to lock up and not flow fuel
Solenoid failure A failed fuel or nitrous solenoid can cause serious damage

Ignition RPM limiter
On a stock LT1 or LS1 computer, the rev limiter is implemented by cutting the signal to the fuel injectors so the cylinders have no combustion. If you're running a dry system, which depends on the fuel injectors to provide compensating fuel for the nitrous, losing fuel this way is the ultimate disaster. An aftermarket ignition will typically implement the rev limit by cutting off spark rather than fuel, which is a much safer implementation of the rev limit. Typically, you'd get your stock PCM programmed to set the rev limit up higher than you'll ever expect to go (like 7000RPM), and use the setting on the aftermarket ignition as your actual rev limit.

Window Switch
This electrical device provides an open or closed circuit based on the engine being between two RPM values (hence "window") that you chose, so that you'll only flow nitrous in this range. Why would you do that? Well, for two very different reasons.

At low RPM, think about what's going on: you're spraying nitrous into the intake at a constant flow. That is, the nitrous bottle and solenoids have no idea what RPM you're at, and they're just pushing it into the intake at a constant volume. Inside the engine, though, the nitrous and fuel combination is being sucked into the cylinders during every stroke. The net result is that at low RPM, you're getting far more of the mixture into the cylinders. At 3000 RPM, for example, you're getting twice the amount as at 6000 RPM. So, you can imagine that running nitrous at, say 1000 RPM, is far more stressful on the motor as at 3000 RPM, and typically causes a "nitrous backfire" - meaning that the nitrous/fuel combination can explode in the intake manifold (rather than the cylinders) - a bad thing. So that's why you don't want the system triggered at low RPM.

At high RPM, the situation is easier to explain. Given the discussion of the rev limit above, you may just want the nitrous system to cut off before hitting that rev limit. If you've got a stock LT1 or LS1 ignition, you certainly want a window switch. If your rev limit is implemented by an aftermarket ignition, it's perfectly safe for the motor to run nitrous during the rev limit. It's not particularly easy though, on your transmission or clutch to have all that power during the shift, which may be a reason to keep the window switch set a bit before you shift.

Fuel Pressure Safety Switch (FPSS)
This is a device that's plumbed into the fuel system, and provides an open or closed circuit based on availability of fuel pressure. It can be used in the triggering circuit to make sure the system isn't on when you've got a fuel problem. Typically, you only use it to switch off the nitrous solenoid; turning off the fuel solenoid as well can start a cycle of switching the solenoids on and off while the pressure raises and drops in the fuel system when you're switching the solenoid on and off. Let the pressure build up in the fuel lines when you open that solenoid, and when it's high enough, the nitrous solenoid will open. The switch can be used whether you've got a wet or a dry system. You can adjust the pressure at which it triggers by using an allen wrench on the back of the switch (loosen the screw lowers the pressure threshold).

You want to set the pressure on the FPSS, such that if the pressure drops about 10psi the nitrous system will shut off. On a wet LT1 system, this will be around 33psi, and on a dry system I'd leave the switch just above stock, say 45psi.

To set the threshold pressure, you've got a few options"

Connect enough plumbing so that you can have the FPSS installed at the same time as a fuel pressure gauge. Turn the key on to pressurize the fuel system, then turn it off. As the fuel pressure bleeds down, monitor the continuity across the FPSS contacts (disconnect them from the rest of the nitrous system) and when the pressure reaches the level you're interested in, adjust the screw on the back so it just balances back and forth between the continuity signal.

You could use an air compressor, with the appropriate fitting for the FPSS. Remove the FPSS from the car, and thread it onto the compressor. Set the compressor for the pressure of interest, and measure continuity as above.

If you can't do option #1 above because you don't have two available ports, first thread in the pressure gauge, and cycle the key. Then time how long it takes for the pressure to bleed down to the correct level. Then disconnect the pressure gauge, install the FPSS, and do the process against the clock rather than the pressure.

Timing Retard
A nitrous/fuel mixture increases the burn rate in the cylinder, and typically adding a few degrees of timing retard is recommended for safety. A rule of thumb is two degrees per 50hp of nitrous, but this will also reduce the power generated. When I tune my system, I monitor engine knock, and retard the timing only enough to eliminate the knock, which is usually about one degree per 50hp. At the track, under harder conditions (actually pulling the weight of the car, possibly higher outdoor temperatures, etc) I'll add a degree of retard.

The LT4 Knock Module is a common modification to 4th generation f-bodies. This device dulls the sensitivity of the knock sensor readings, which allows the PCM to avoid seeing noises from headers, exhaust and loud valvetrain parts incorrectly as knock. The net result is that the overall timing of the engine is advanced a bit, and the PCM is a bit less sensitive to all knock, whether real or false. Unfortunately, knock when running nitrous has more of a chance of doing damage, and it's not at all clear that using a LT4 KM while running nitrous would be a good thing. Personally, since I tune my nitrous while watching knock, and retard my timing as well, I do use the LT4 KM. Once again, though, it's your call on all these safety issues.

Nashua_Night_Hawk

I hate to see a nitrous kit and hitting the rev limiter, cuting off the fuel, going lean and... Ka BOOM!

98AcuraCLpimp

so where do i get a ""window switch" and can it be used in conjunction w/zex and thanks for all the info!

lnsyone

just search for MSD window switch activator on ebay