The purpose of this thread is to post all basic/pertinent information about using nitrous with the sr20. Everybody post stuff up as you think of it.
Hopefully this thread will help forum members when they first start researching nitrous and it will be a good reference to anyone else who may need it.
The Kinds of Nitrous Kits :
Wet Nitrous Kit :
Wet nitrous kits have a fuel solenoid and nitrous solenoid that allows for fuel to be sprayed along with nitrous. The fuel mixing with the nitrous allows for the motor to avoid running lean due to lack of fuel and it helps to prevent detonation. This is why you can typically run a larger wet shot on stock fuel delivery components then a dry shot.
Dry Nitrous Kit :
Dry nitrous kits have a nitrous solenoid that allows for a specified amount of nitrous to spray without the adding of fuel. This type of kit relies on stock fuel delivery (i.e. – injectors, fuel pump, exc…. ). When increasing shot size on a dry kit it is necessary to upgrade fuel delivery components to avoid detonation and eventual engine failure due to the motor running a lean condition.
Direct Port Kit :
Direct port kits run both nitrous and fuel to nozzles that have been tapped into the intake runners of the intake manifold. A direct port allows you to run a much larger shot then a wet or dry kit and it also allows for a much more equal distribution of nitrous to all the cylinders
Nitrous Accessories :
Bottle Warmer -
Heats the nitrous bottle until the nitrous inside reaches a specified pressure at which the nitrous will produce power at it’s full potential.
Purge Kit -
Allows the driver to "purge" the nitrous lines of all air and nitrous that was not completely used when the system was last used.
Window Switch –
This device will only allow your nitrous to spray between a driver specified “window” in the rpm range. For example, if you select a beginning of 3500rpm and an ending of 8000rpm then the nitrous will only spray between 3500 and 8000 rpm’s. This tools can be used as a fail safe for lower shots making sure that you do not engage the nitrous at to low of an rpm. This is of greatest use to someone who runs a larger shot, particularly because the driver can make sure that they set the end of the window at a prior rpm to the fuel cut, so that they don’t accidentally continue spraying after they’ve reached fuel cut.
Bottle Blanket –
Insulates the nitrous bottle to help maintain consistent temperature/pressure.
Blow Down Tube –
This is an externaly vented tube that runs from the nitrous bottle to the outside of the vehicle. In the event that the bottle becomes to pressurized, a valve opens releasing the contents of the bottle through the tube. This is required at some tracks in order to use nitrous.
Nitrous Pressure Gauge –
This gauge allows you to monitor your bottle pressure.
EGT Gauge –
( Exhaust Gas Temperature = EGT ) This gauge allows you to monitor your exhaust temp. This is a good indicator as to wether you need to let your motor cool before use or if it is alright to use your nitrous again. Helpful in prevention of overheating/overworking your motor.
A/F Gauge –
( Air / Fuel ) This gauge allows you to make sure that when using nitrous, that you do not run lean.
Progressive Controller -
This allows a gradual increase in nitrous as your rpm’s increase. For example (keep in mind, this is hypothetical – not necessarily the rpm that you have to switch shot size at), to start you are spraying a 50 shot off the line, once you reach 4k rpms you are up to a 75 shot, once you reach 5.5k rpms you are up to a 100 shot and by redline you’re spraying a 125 shot. This “progressive” increase in nitrous allows you to run a large shot without putting sudden strain on your engine’s internals (especially on the connecting rods in the sr20’s case).
WOT Switch -
( Wide Open Throttle = WOT ) This switch will only allow nitrous to be sprayed when the throttle is wide open.
Miscellaneous Information :
Recommended Spark Plugs :
Gapping between .035 to .038 depending on size of shot.
Recommended Bottle Pressure :
1000 -1200 psi - Bottle is fully pressurized and will produce the best results.
600 - 700 psi - Bottle is nearly empty – Go refill.
Retarding timing according to the shot size is necessary to avoid detonation. Below are the suggested timing retard settings according to the shot size. It is always a good idea to referance your kit’s manufacturer’s suggested timing information, but below is a general guideline of typical recommendations.
50 shot - 0 - 1 degree timing retard
75 shot - 2 degree timing retard
100 shot - 3 degree timing retard