FOR THE INTERESTED AND SKEPTICAL
Most nitrous horror stories come from situations where people try to add 250hp to a system (engine, drive train, driver) that simply won't handle it, or build a system that lets the engine run lean. Also, there are THREE different approaches, based upon what happens when the hammer is going down.
WET systems spray gas when or even before the nitrous begins. A good design ensures that the engine never goes lean. DRY systems spray only nitrous, depending upon the O2 sensor to tell the computer to add gas. The engine doesn't need to run lean for very long to be damaged.
Assuming a wet system, there's also the matter of WHEN nitrous and gas are sprayed. It cannot be done at low or max RPM - there's a "window" in which the added power can be handled safely. Therefore, a good installation will include a (great name) WINDOW SWITCH that prevents nitrous outside a preselected range.
For more than a 50hp shot, even in a wet system, there should be other modifications to improve functionality and reduce risk of damage. The third approach is WET plus OPTIMIZATION.
One must consider the fuel system and the exhaust. The injectors (supported by a competent fuel pump!) must flow enough gas to avoid risk of any cylinder going lean. I just installed a new fuel pump, screen, filter, and WIRING to ensure fuel adequacy. Also a big nitrous shot will generate a lot of exhaust gasses, and some stock systems won't flow it - creating back pressure and the probability of (valves, I think) damage.
Some drivers will keep the bottle's valve open at all time, because every stoplight is an opportunity to spray nitrous and testosterone - a dangerous combination. I've met people that go through more than 50 pounds a month! I've never used more than 10 pounds in a month, including a trip to the drag strip, and in most months my usage is less than 5 pounds. If a conservative driver uses nitrous only occasionally/properly, a solenoid-controlled (a motor is too slow) valve is important. I used TPS data to open the valve when the throttle reached a selected point beyond normal acceleration, and read RPM to spray
only within my preselected RPM+TPS range. When I backed off on the throttle and returned to normal TPS range, the valve would close. There are a few cars in this area using that configuration with good - and safe - results.
A nitrous system on the 2.8 will do more per dollar than an engine upgrade. That's an easy +100hp for $500-600, and in the Fiero the installation would be virtually invisible yet removable in 15 minutes. Also, when not "on the bottle" you will have the same fuel efficiency as before nitrous, while a big engine will burn more fuel at all times.
I talked myself into this... it'll be my summer project for this evolving '88GT.
[This message has been edited by notaguru (edited 05-08-2014).]