Custom PCM mods to support nitrous
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Custom PCM mods to support nitrous
(also posted under N2O tech section)
We've been developing custom programming for 99+ LS1 PCMs to support nitrous systems and we wanted to let you know about the project.
Nitrous system makers typically recommend that nitrous shots only be activated at wide open throttle, and above 3000 RPM. Many stand-alone nitrous kits come with microswitches attached to the throttle linkage to activate the system.
Furthermore, in cases where large nitrous shots are run, it is usually necessary to add additional fuel to maintain proper air to fuel ratio and adjust the timing to reduce the chances of experiencing spark knock. Many nitrous kits will use a mechanism that adds fuel to the intake manifold separately.
Our custom PCM mod eliminates both the need for a throttle microswitch and plumbing additional fuel into the intake manifold. By wiring an "arming switch" to an unused input at the PCM, and the nitrous solenoid to the EGR control output, the PCM can decide when to activate the nitrous by checking whether the throttle position sensor is reporting a >90% throttle position and the RPM is between 3000 and 5500 RPM. All of these parameters can be adjusted.
Additionally, this PCM mod can optionally use an alternate timing and PE mode table so fueling and timing for the nitrous system can be adjusted separately.
We are currently testing this on our stock 1999 Z28, with a single nozzle, an .039" jet, and on the dyno this produced about 100HP at the crankshaft. This is interesting, but it's not at the power level where additional fuel is generally required. We're going to test an .055" jet on it soon, which should produce closer to 200HP, which, without a PCM mod, would require additional fuel (a wet shot). We're going to prove that this PCM mod can support a large shot without additional fuel injected into the manifold (because we can make the PCM add it for us with the alternate PE mode table).
We plan to make this feature both available in the form of a stock calibration file, for people that do their own tuning, and as an option with our full custom programming.
If this is something that you might be interested in, feel free to send us mail at info@trifectaperformance.com
We've been developing custom programming for 99+ LS1 PCMs to support nitrous systems and we wanted to let you know about the project.
Nitrous system makers typically recommend that nitrous shots only be activated at wide open throttle, and above 3000 RPM. Many stand-alone nitrous kits come with microswitches attached to the throttle linkage to activate the system.
Furthermore, in cases where large nitrous shots are run, it is usually necessary to add additional fuel to maintain proper air to fuel ratio and adjust the timing to reduce the chances of experiencing spark knock. Many nitrous kits will use a mechanism that adds fuel to the intake manifold separately.
Our custom PCM mod eliminates both the need for a throttle microswitch and plumbing additional fuel into the intake manifold. By wiring an "arming switch" to an unused input at the PCM, and the nitrous solenoid to the EGR control output, the PCM can decide when to activate the nitrous by checking whether the throttle position sensor is reporting a >90% throttle position and the RPM is between 3000 and 5500 RPM. All of these parameters can be adjusted.
Additionally, this PCM mod can optionally use an alternate timing and PE mode table so fueling and timing for the nitrous system can be adjusted separately.
We are currently testing this on our stock 1999 Z28, with a single nozzle, an .039" jet, and on the dyno this produced about 100HP at the crankshaft. This is interesting, but it's not at the power level where additional fuel is generally required. We're going to test an .055" jet on it soon, which should produce closer to 200HP, which, without a PCM mod, would require additional fuel (a wet shot). We're going to prove that this PCM mod can support a large shot without additional fuel injected into the manifold (because we can make the PCM add it for us with the alternate PE mode table).
We plan to make this feature both available in the form of a stock calibration file, for people that do their own tuning, and as an option with our full custom programming.
If this is something that you might be interested in, feel free to send us mail at info@trifectaperformance.com
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