The VCN-1000 system was sent to me in exchange for the previously purchased Saturn-specific VCN-2000 system which did not function correctly on my 92 SC.  If you haven't yet read my write-up of the 2000 system, please read it here before reading this article.

Operation

In addition to the standard components found in all kits (bottle, lines, nozzles, solenoid, wiring), this system provides a wired display, a main control unit, and an assortment of different diameter nozzles.

• LEDs on the driver display indicate mixture rich/lean conditions based on readings from the oxygen sensor. If a lean condition is detected while the unit is active that cannot be corrected (see below), the system will shut itself down.
• If the oxygen sensor readings indicate a lean condition, the control unit will supplement the pulse time of the factory fuel injectors, adding more fuel. While most people would call the VCN-1000 kit a "dry" setup (as it does not use an additional solenoid and nozzle to inject more fuel into the intake stream), it doesn't quite fit into that category due to its effect on fuel control using the stock injectors. The system is a true closed-loop system, which in theory should make it a much safer system than your average nitrous kit - wet or dry.
• Throttle position is monitored, and when wide-open throttle is detected, the flow of nitrous oxide is turned on.

The cockpit-mounted display has LEDs to show system status and any error conditions, as well as an indication of whether the mixture is rich/lean. It also has a switch to make the system active.

The amount of nitrous sprayed into the intake can be changed by swapping out colored nozzles. Each color is rated for its orifice diameter - the Venom manual doesn't list how much horsepower each will add.

Installation

Just like the detail-oriented and time-consuming install process I went through with the VCN-2000 system, I took as much time as was necessary to do it right, make it look good, and be sure that everything functions correctly. I spent an enormous amount of time wrapping everything in wire loom, routing wiring and lines in the best locations and out of the way (and hidden whenever possible), and making everything look as perfect as I could. In fact, most of the components were installed to be quickly and easily removeable for when I'll be on the road course and the system will not be in use. Quick-release fasteners were used on much of the hardware, and Molex connectors were used for all the electrical connections.

In addition to all the standard parts included in the kit, I added a purge solenoid, blowdown tube, pressure gauge, and a new bottle fitting which allows it to be connected to the blowdown tube. Since this system provided no control over RPM engagement and shutdown points, a NOS window switch was added along with add-on RPM selector modules for both high and low. This would allow fine-tuning of engagement & shutoff RPM with the turn of a dial.

Click the thumbnails below to view a larger-sized image.
  

Initial start-up of the vehicle showed a constant and unchanging rich condition on the display unit's status LEDs. In fact, the system still felt the mixture was rich when removing its connection to the vehicle's oxygen sensor (the zero voltage should have been interpreted as lean). A phone call to Venom tech support followed, and once again, I had to mail the main control module out for repair/replacement and wait for its return. I do not know why it did this right out of the box, but this problem was resolved quickly.

A few test runs on the street with the nitrous nozzle pointing into the open air (and not into the engine's intake) showed that everything appeared to be operating properly. The LEDs indicating rich/lean went back-and-forth at part-throttle, and went full rich at WOT. Nitrous flow engaged at the RPM that I had set on the selector module, and shut off at the designated RPM as well. WOW, all looks good and this thing is ready to spray!
  

The next several runs involved engaging the system, and trying out the first few nozzles provided in the kit with small diameter orifices. The RPM modules were set to engage the flow at 4000 RPM and disengage it at 6000 RPM (a pretty narrow band initially chosen for safety reasons). Oddly, they provided virtually no added horsepower compared to the runs done when the system was turned off.

The third nozzle size seemed to to do the trick. The third gear dyno pull started out at a low RPM. When the spray engaged at the set 4000 RPM point, the loud SHHHHHHHH noise could be heard and the rate of acceleration increased dramatically. The car lurched on the straps and reached redline much quicker than I had expected and thought it could. The readings on the dyno shop's wideband O2 monitoring equipment looked good and the mixture was healthy throughout the run. As the dyno spun down and the computer calculated for a few seconds, we were rewarded with some very nice numbers on the screen.

The best run showed 179 horsepower and 187 ft. lbs. torque.  Nice.  We did a handful of back-to-back runs. Oil and coolant temp looked great, the O2 was where it was supposed to be, and the hp/torque output from one run to the next was consistent. And the best part about it was how effortless the vehicle and system made it appear. While I was still in a cautious frame of mind, the dyno operator was eager to try some of the other nozzles with larger orifices. Unfortunately, the time I'd reserved on the dyno this day had run out, and I would have to save it for a different day.

Click the thumbnails below to view a larger-sized image.
  

Best run during first
visit to dyno.
  

A run showing readings
from the wideband O2 sensor.
  

There's still a lot to go on this project.  How does it perform on the street?  How about the dragstrip?  How much more of a shot can we spray and still show good air/fuel mixture readings while on the dyno?  You better believe I intend on pushing it to the max and seeing what it can do.

Update - beyond the dyno... (click the NEXT link below)