By David Koehler
copyright
You may create
a link to this
article.

You may not
copy / paste it
to another site
without
permission.
What is it? A nitrous controller is often called a progressive box. A
progressive box is an electronic gadget with a miniature computer. It
allows you to limit the flow rate of nitrous and fuel available to the
nitrous system and consequently the useable horsepower available to
the tires.

The word progressive is supposed to mean that if you had jets in your
nitrous system that could potentially produce 300 HP, you could set
the controller to pulse for a period of time, limiting the HP and then
ramping back up to full flow HP in the time span you dictate. This
description is not entirely accurate, however.

It's kind of misleading to think that your HP is cut in half, for instance.
Nothing has really changed as far as the potential HP level is
concerned, which is dictated by your jets and pressures. What is really
happening is that the solenoid is opening and closing enough times per
second to limit the amount of time that the maximum flow rate is
available to the jets. We call this opening and closing "pulsing",

Think of it this way. If you are in front of a spinning revolving door is it
open or closed to you? Obviously only part of you can get through
unless you are super human quick, so it is closed for a moment. Open
it a little slower and you can sneak by if you are quick enough. The
same principle is how nitrous controllers operate. A nitrous controller
slows down the maximum flow rate by turning the flow on and off in
short bursts over a period of time.
A nitrous controller is desired to soften the incredible torque spike that
occurs with each stage of nitrous activation. You may have an engine
with more torque than the car or track can handle or you have a tire
limited class car (or both) with no wheelie bars and it has a tendency to
spin the tires. If you use a controller and reduce the amount of nitrous
available to the engine just long enough to get the car moving forward
then ramp in the full charge you will improve your ET, guaranteed.

Some folks try to do the power reduction with ignition retards (reducing
total timing) combined with delaying the nitrous activation but this can
bite you by producing bumper dragging wheel stands. While this works
in some cases it is hard to take enough timing out and not have the
pinion try to climb the ring gear and wheel stand the car. When you pull
the timing back too far from the engine's ideal point and the nitrous is
not activated, the engine really runs sour. While this wheelstand may
get your car featured in DRO, you won't win the race.

If you use the nitrous controller instead of ignition to accomplish this
you can leave the timing where it needs to be with the nitrous on and
avoid extreme wheel stands and losing. Usually it only requires 0.5 to 5
tenths of nitrous progressive duration to make the chassis work as it
was intended and stick the car to the track.
Review of Racing Instrumentation's  Nitrous PROgressive Controller
Why and when you need to use a nitrous progressive controller
I am fortunate to be able to R&D some cool products that come through
the shop from various manufacturers for independent testing. R&D
means that I test and look for ways to improve the product, ask as
many end user questions as possible, and try to kill the product at the
same time. From time to time, with the client's permission, I will show
you products that work well and how they work. I will also be adding
some articles on just about anything that I feel might be useful and
worthy.
Nitrous progressive controller
Site Map
2005-2010
All Text and images on this website are copyrighted by David Koehler 2000 and beyond
All sales are final. Items and services provided by Koehler Injection are intended for off road use only.
No responsibility whatsoever will be accepted by Koehler Injection for any damage, injury or loss resulting from their use.
Nitrous Master.
Urbana IL, USA    217 469 7663     M-F  9 - 5 CST
Postal Money Order
machine shop engine industrial balancing, fuel injection flow tesing urbana IL
Urbana IL, USA 
217 469 7663  
M-F  9 - 5 CST
Many Photos may be enlarged
by clicking on them.
Postal Money Order
Nitrous Oxide
Fuel Injection