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Discussion Starter #1 (Edited)
PROPERLY getting set up to run nitrous on a 2006 2.5i

im debating the installation of NOS on my '06 2.5i when the warranty runs out, and im stuck at whether wet or dry nos is safer. my concern is not necessarily the most power, but the most life out of my engine. anyways ive got a question....

Theoretically......if using a "dry" NOS setup, the intake sensor would detect the extra oxygen, and add more gas, correct? would it trigger a CEL in the oxygen sensor in the exhaust?


regards........
 

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nees said:
my concern is not necessarily the most power, but the most life out of my engine.
Life expectancy of an engine reduces proportionate to the performance increase. If you're worried about engine life, the only safe path is not to mod. Period.

For warranty, keep in mind that your 06's powertrain (engine/tranny/diffs) warranty is 5 years/60,000 miles, you've got a long way to go and planning for nitrous now is pretty dumb.

Theoretically......if using a "dry" NOS setup, the intake sensor would detect the extra oxygen, and add more gas, correct?
Wrong. The MAF sensor measures airflow into the engine, not oxygen. Nitrous is injected AFTER the MAF and is not factored in to the MAF reading. Injecting it before the MAF would destroy two things, the MAF itself (heated sensor hit by supercooled gas = destroyed sensor), and the secondary effect of nitrous, which is cooling. You want it injected as close to the throttlebody as possible.

Further, by the time the O2 sensor in the exhaust see's the increase in oxygen injected into the engine, the engine has spun a couple times on nitrous and that's enough for detonation to occur. The ECU needs to know in advance that nitrous is being injected and how much to compensate.

You can get to this in two ways with a dry kit:

1. All dry kits come with a fuel pressure riser that increases fuel pressure at the time the nitrous is injected. This "tricks" the ECU into adding more fuel until the ECU can properly compensate for it. It's not perfect, most setups see a brief very-lean condition at the time the nitrous kicks in, but it gets the job done.

2. The best way, is tuning specifically for nitrous. This would retard the timing slightly and increase fuel delivery at the same rpm where your nitrous switch is set to deliver the spray (NEVER USE THE FAST & FURIOUS NITROUS BUTTONS). Consistent, safe delivery everytime, but it effectively doubles the price of the nitrous setup.
 

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Discussion Starter #3
ok...retard timing....by how many degrees though?

and as for nitrous.....the wet system adds the nitrous with the fuel, before its injected so would i be able to skip the whole lean problems with simply using wet over dry?
 

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nees said:
ok...retard timing....by how many degrees though?

and as for nitrous.....the wet system adds the nitrous with the fuel, before its injected so would i be able to skip the whole lean problems with simply using wet over dry?
Wet is better but individual dry with something to control the timing/fuel and delivery of the nitrous is the best. To do that you probably need a good standalone. AEM or Hydra would do the trick. But that is not for most people.
 

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nees said:
ok...retard timing....by how many degrees though?
Depends on the shot and what your datalogs say. That's why they call it "tuning" and not "pick a random number and hope it doesn't blow up".

and as for nitrous.....the wet system adds the nitrous with the fuel, before its injected so would i be able to skip the whole lean problems with simply using wet over dry?
Wet injects more fuel with the nitrous, you match the fuel jet to the nitrous jet. Problem with the wet kits is you can have fuel pooling inside the intake manifold which can eventually explode.

Either way, if you're waiting for warranty to run out, you won't be doing this for another 3-4 years anyways. I wouldn't worry about it.
 

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Brydon said:
Wet is better but individual dry with something to control the timing/fuel and delivery of the nitrous is the best. To do that you probably need a good standalone. AEM or Hydra would do the trick. But that is not for most people.
Actually a piggyback like PP6 would work just fine. You only want your nitrous kicking in at WOT and higher RPM's (AKA. open loop) which is where a piggyback has control of the situation. Should be plenty to handle a basic dry kit.
 

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Discussion Starter #7 (Edited)
i wasnt aware that pp6 was avail. for us '06ers yet.

ZEX nitrous systems has some new feature that supposedly eliminates lean/rich running. forget about the warranty, if something goes seriously wrong, ill just uninstall the kit. ill take the chance. see teh quoted text from ZEX's website below:

" • ZEX Nitrous Systems have an advanced, patented feature called "Active Fuel Control". This feature monitors nitrous bottle pressure and adds or subtracts enrichment fuel. The engine never runs too rich or too lean when engaging the nitrous system."


this is from dry part#82011 on ZEX's website.



...and what did you mean about the BS fast and furious switches? my plan was to have something completely hidden, either a switch at the pedal for full throttle, or some kind of "paddle" trigger on the backside of the steering wheel i could hit with my fingers like the cool shifter paddles in modern sport scars.
my goal: to make wrx drivers kill themselves with curiosity as to why t hey just got beat by an RS.

regards........
 

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FalconRS said:
You only want your nitrous kicking in at WOT and higher RPM's.
Not necessarally. I would want switching control and fuel/timing control done without me touching a thing. I would also want it turned off between shifts/over boost/and over rev. Although I would probably only use it for pre boost launching turned off when in boost and above 10mph. I don't believe the pp6 can do that. You could tune a second map for pure nitrous but this may change with bottle temp and pressure.

On a side note I have seen a nitrous RS run low 13s tuned with a pp6.
 

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nees said:
i wasnt aware that pp6 was avail. for us '06ers yet.
It's been available from the minute the first 06 hit a dealer's lot. They've even had plug and play wiring harnesses available for over a year. Wake up.

ZEX nitrous systems has some new feature that supposedly eliminates lean/rich running. forget about the warranty, if something goes seriously wrong, ill just uninstall the kit. ill take the chance. see teh quoted text from ZEX's website below:

" • ZEX Nitrous Systems have an advanced, patented feature called "Active Fuel Control". This feature monitors nitrous bottle pressure and adds or subtracts enrichment fuel. The engine never runs too rich or too lean when engaging the nitrous system."

this is from dry part#82011 on ZEX's website.
If only the world were perfect. But it's not. Do it right.

...and what did you mean about the BS fast and furious switches?
What I meant was....

some kind of "paddle" trigger on the backside of the steering wheel i could hit with my fingers like the cool shifter paddles in modern sport scars.
Modern nitrous kits plug into the throttle position sensor and monitor engine RPM. When you hit WOT and a given RPM point (basically open loop) it automatically fires the nitrous when the system is armed. The only switch you have is a toggle switch to arm/disarm the system. The system itself makes the decision when to fire. Trust me, it's MUCH smarter than you are.
 

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Brydon said:
Not necessarally. I would want switching control and fuel/timing control done without me touching a thing. I would also want it turned off between shifts/over boost/and over rev. Although I would probably only use it for pre boost launching turned off when in boost and above 10mph. I don't believe the pp6 can do that. You could tune a second map for pure nitrous but this may change with bottle temp and pressure.
Zex's nitrous controllers use an activation point (TPS and RPM) and a deactivation point (RPM) to prevent over rev situations that occur between shifts. And the controller (as nees posted) can adjust to an extent for bottle temp/pressure, the PP6 would be used to keep timing and base fuel under wraps starting at the nitrous activation point. Done right, it's pretty idiot-proof, though it sounds like nees may be out to prove me wrong on that.

As for the rest, we're talking about an n/a application. If you want to talk nitrous and boost, make your own thread.
 

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Discussion Starter #11 (Edited)
ok, say....i cant afford a pp6, and i would like to do this without....(correct me if im wrong) but you're basically saying a dry system is the best choice....at least over wet.
any recommendations on a part no.? NOS? ZEX?

and i guess scratch the idea about the cool manual shifter paddle boost switch?
 

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Zex 82011 is the best choice. Zex makes the safest, most idiot proof systems out there. But unless you've got at least a header on the car I'd stick to the smallest shot, which I believe is a 55-shot on that kit.
 

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would a SAFC be sufficient to keep engine from blowing up?

and could u not rig up the SAFC (set to retard timing/increase fuel in Open loop) to a switch so that the SAFC is completely bypassed (zero correction) when the nitrous system is disarmed, but then correcting when system is armed? seems that would be much more practical than having to switch maps everytime....
 

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There's a reason it's called an SAFC and not an SAFTC. No timing control. It'd be fine to richen up the fuel right at the activation point to prevent a lean condition though. The SAFC can be wired for nitrous, if I remember right, and is a nice band-aid solution for it.

Let me clarify one thing, the zex kit is relatively safe on its own. But for longevity of the motor and overall safety, particularly if you plan to go beyond the smallest shot on the kit, some additional tuning measures should be taken.

That said, tuning tools in the hands of the ignorant and/or stupid is as dangerous (or more) than a nitrous hit.
 

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Discussion Starter #15
...what about refills? i know theres a NOS fill station about 40 miles from me, but if it a NOS certified fill station....does that mean they wont accept anyones bottles but NOS? i mean nitrous is nitrous......
 

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nees said:
wow....sometimes i sware you seem like you have something against me.
Actually like much of what I say, that was a general statement, since there are only a handful of people here that actually know what they're doing with tuning gear. A lot of people think I have something against them because they like taking everything I say personally. Paranoia is their (your) problem, not mine. Get help.
 

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Discussion Starter #19
now obviously, im sure you know that if i do get this baby installed, im going to hit the 75 shot JUST to see what its like. Now i dont plan to make it a routine thing, but....as for upgrades to handle the extra pressure wrx injectors would seem logical...or? what is the psi of the stock fuel system in an '06 rs?
 
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