MembersPage/GergelyLezsak/Nitrous (2009-07-15 19:06:37)

Nitrous control

As many of us using big turbos (especially me :), it's a good idea to spool it with nitrous injection.

Unlike with other technics (launch and ALS), I'd like control it a way to stay in traction which is much favourable in street conditions.

My first idea is a dry kit with PWM-able solenoid, like this one:

http://www.noswizard.com/product_desc.php?id=6

Interesting part is controlling such a system with VEMS.

I thought a pwm reference table similar to current boost reference table logic, RPM and KPA for axis, and duty for values.

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Existing logic is probably OK to switch configs when N2O is on or off, to handle ignition change (and fuel?)

Or alternatively if this is hand-in-hand by nitrous volume (rated by pwm duty) a simple config value is enough information to add extra fuel(?)

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AFAIK this is not common in other (big brand) ECUs, so it might be a good idea to take advantage and give support for such an advanced (and cheap) control possibility.

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Sizing

Based on existing measurements I can achieve 0.8-0.9G acceleration with warm tires but excessive wheelspin, maybe it would be slightly more with a 5-10% of slip.

Here's a power chart of a first-gear run with launch&wheelspin (black) and with simple acceleration (red):

hp-curve.png

(Time differences between the curves are scaled)

Based on the blue area, I'll need a maximum of ~70Hp "shot" of N2O.

For a test-drive open loop boost control with ref table (RPM, kPa) is usable I guess, usage frequency of the solenoids ("Pulsoids") seems 8-50Hz.

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UPDATE july, 2009

New firmwares (like 1.1.56) have experimental N2O control to switch a simple solenoid and some correction in fuel+ignition. This is fine for an ordinary one-stage system, but it cannot control more stages or the finest PWM-based systems I described above.

Write your thoughts here!