©2008 Edelbrock Corporation
Brochure No. 63-0003
Catalog #70060, #70061, #70063
Rev. 7/08 - AJ/mc
Page 2 of 4
Baseline Tuning Suggestions
Utilizing nitrous oxide as a power adder is similar to a supercharger or a turbocharger in that it increases the amount of air an engine can get from
atmospheric conditions. There are some significant differences:
1.
The “air” in nitrous oxide is very oxygen rich. This oxygen is of a much higher density, so the opportunity to extract very high quotients of
power is very high.
2.
Nitrous oxide injection does not have a parasitic load factor associated with its use like a turbocharger or a supercharger. Meaning, it does not
cost as much horsepower as a crank-driven supercharger or an exhaust driven turbocharger.
The most important thing to remember when looking at baseline tuning issues associated with nitrous oxide is that a Nitrous “rich” condition is bad.
Two parameters that will keep you from catastrophically affecting your engine are:
Nitrous Bottle Pressure:
Always keep your bottle pressure between 900 and 950 psi. Yes, there are racers that use different pressures,
but the testing we did here at Edelbrock to ensure the jetting maps within this manual are correct, was done in this pressure range. Use any
higher pressure than 950 psi and your engfine will be lean. Use any pressures below 900 psi and your engine will be rich.
Fuel Pressure:
Always ensure you have between 6 and 6.5 psi of fuel pressure every time you enable your nitrous system. We used 6
to 6.5 psi of fuel pressure to perform our jet map testing on this system. If you do not have at least 6 psi of fuel pressure going to the fuel
solenoid, when it is activated, your engine will be lean. If you were to have more than 6.5 psi of fuel pressure to the fuel solenoid when it is
activated, your engine would be rich.
There are many different ways to jet to a specific power level. However, for the continued safe operation of your nitrous system, we suggest you do
not move too far away from the jet map listed within this manual. Catastrophic engine failure could result.
Your Performer RPM nitrous system comes with matched sets of nitrous and fuel jets. These are validated jetting combinations, based upon 900 to
950 psi nitrous oxide bottle pressure, and 6 to 6.5 psi flowing fuel pressure. Operating with these pressure levels should yield safe and reliable
power increases.
Spark Plug Facts
The most important aspects to be considered when selecting a Spark Plug for your nitrous combination are, but not limited to: heat range, firing end
design, material construction type, reach, thread size, and gap. We advise lowering the heat range of your spark plugs 1 to 2 steps for every 100 hp
added with nitrous. We do not recommend the use of Precious metal type plugs i.e.: Platinum, Iridium, Gold Palladium, or Yttrium. The tips on these
types of plugs can get very hot and cause detonation. It is best to use a non projected tip plug without a fine wire center electrode designed for a
gap between .025" and .035" with a shorter preferably thicker ground strap. Never try to gap a plug designed for a .060" gap down to.035".
Edelbrock recommends an NGK spark plug with a heat range of -9 to -11 depending on the nitrous power level being tuned. When in doubt, always
go to the next cooler heat range plug.
How To Read Spark Plugs From A Nitrous Oxide Injected Engine
:
Spark plugs are a window into the combustion chamber. They will tell many things about the operation of the vehicle. Here are some tips on looking
at spark plugs to “read” what is happening with your engine:
•
Correct timing, mixture and spark plug heat range
Ground strap retains “like new” appearance. Edges are crisp, with no signs of discoloration. Porcelain retains clear white appearance with no
“peppering” or spotting.
•
Excessively rich mixture
Porcelain may be fuel-stained, appearing brown or black. In extreme cases, ground strap, electrode and porcelain may be damp with gasoline,
or smell of fuel.
•
Detonation
Edges of ground strap may become rounded. Porcelain has the appearance of being sprinkled with pepper, or may have aluminum speckles.
During heavy detonation, the ground strap tip may burn off. This phenomena can result from excessive ignition timing, too high a heat range
spark plug or inadequate fuel octane.
•
Excessively lean mixture
Edges of ground strap may become rounded. Under moderate overheating, the tip of the ground strap
can
discolor, usually
turning purple, or the entire ground strap can become discolored.
