Mike S

Just one note to add also. That dude who blew his maxima up had altered the pressure releif valve. He was modifying it in an attempt to fill it to a higher pressure and carry more nitrous. This was what the nitrous manufacturer had stated, so take that for what its worth.

Jfrahm

Hmmm, Nitrous is a liquid in the bottle, so I don't think you could carry more of it by altering the burst disc. I think it's delivered to the manifold as a liquid too. You might be able to supply more liquid per unit time at a higher pressure through. The burst disks are set for over 3000 psi, over double the pressure of Nitrous as a liquid.

-Joel.

mideastmafia

[quote]Originally posted by Jfrahm:
<strong>Hmmm, Nitrous is a liquid in the bottle, so I don't think you could carry more of it by altering the burst disc. I think it's delivered to the manifold as a liquid too. You might be able to supply more liquid per unit time at a higher pressure through. The burst disks are set for over 3000 psi, over double the pressure of Nitrous as a liquid.

-Joel.</strong><hr></blockquote>


nitrous can also be a gas. thats the difference between and WET and DRY system


SHAUN

Danno

"nitrous can also be a gas."

Yep. Whenever you inject nitrous into a car, it will always be a gas... I don't think that has anything to do with wet & dry. See here for a real good explanation of wet & dry nitrous systems: <a href="http://forums.rennlist.com/cgi-bin/rennforums/ultimatebb.cgi?ubb=get_topic&f=18&t=001961" target="_blank">Topic: Anyone successfully installed nitrous on their 951?</a>

mmmbeer

Dry injects the nitrous only (DME needs to handle extra fuel), while wet meens that nitrous and fuel are mixed before delivery to the engine.

Eirik Kvello-Aune
<a href="http://www.diateam.no/porsche" target="_blank">www.diateam.no/porsche</a>

Jfrahm

Nitrous at these temps is a liquid under pressure, like propane or CO2. It flows as a liquid to the solenoid and even to the nozzle. It's the phase change to gas as it sprays out that has the great cooling effect. The bottle pressure stays very consistent until you are out of liquid, then you are pretty much out of N2O too. The pickup in a nitrous bottle is positioned such that it draws liquid out of the bottom of the bottle. It's just like a propane tank, liquid on the bottom, gas on the top.
When you fill a nitrous bottle you fill it with liquid N2O. It's not like a SCUBA tank, which is full of gas under high pressure. That's why the fill stations either have a big upside-down bottle or a pump.

-Joel.

Jfrahm

Yes, a dry system only injects the gas (or more accurately it sprays a liquid into the manifold which changes to gas right away, like a CO2 fire extinguisher.) A wet system also sprays fuel. Dry systems have to get their fuel from the injectors, and usually have a system to crank up the fuel pressure. They can cause problems if they cannot get enough fuel via the injectors. The wet systems are more prone to backfires in the intake and fuel puddling in manifolds that were not designed to flow anything but air.

-Joel

Kurt

thanks for the technical details
NOS has a kit for $670 thats 50-60 HP, and supposedly doesn't require additional parts

i think i might go for it next spring to have the whole summer to play around with it

44mag

You guys aren't going to belive this. Ever since the day I bought my 944, my dad has been on a severe jealousy binge. over the past three years this led to headers, a port and polish, and a plane job on the heads, a massive throttle body a performance intake, and intake manifold, a high perf. camshaft, a high stall converter, full performance ehaust system, forged pistons and a 250 shot of nitrous in ... get this his 95 Grand Cherokee!!!!! I cant even come close to him with my 8v na. He's running about 650 horses on the bottle and hasn't been beat yet. its funny because that Cherokee with beat the $hit out of any mustang, camaro firebid or rice car you throw at it. we G-teched it at 13.2 at 108 mph which isn't bad considering the fact that its a 5700 pound daily driven SUV. You should see the looks on 5.0 drivers faces when we blow by them. I'll post pics if you guys want to see them. So now I'm looking into a N20 system to be able to at least stay a few car lengths behind.

Ag951

For not much more money than you're contemplating spending on a nitrous kit, you could get a rebuilt or used turbo charger. A good turbo will give you more than 50hp, will run constantly (minus spool up time), and will never require a refill (just more frequent trips to the gas station).
AutoX and some road racing groups don't allow nitrous, so you can't use it when it's really fun (and legal) to drive like a maniac.
Boost beats the bottle.

Matt O.

In the news article it plainly stated the left the bottle heater on!!! Did those folks just conveniently forget that part??

rarson

Why would nitrous give you positive manifold pressure? It's not adding any air, it's just adding oxygen. The N2O breaks down into nitrogen (a diatomic atom) and oxygen. The extra oxygen added is what makes the power. Air is 21% oxygen, N2O is 33.3% oxygen.

Sorry, I forgot to read the second page of posts before I replied. Also, saturation temperature inside the bottle would be much higher than in the manifold so it probably would be a liquid in the bottle and a gas in the manifold. I assume that's what the heater's for: heat the nitrous to a bit less than saturation temperature for a given bottle pressure, that way when it leaves the nozzle, the phase change is intantaneous. If the heater was left on and temperature reached saturation at the bottle pressure, then some of the liquid would flash to vapor, and eventually the vapor would not be able to compensate for the pressure increase and the bottle explodes. No duh. I have no idea of the design pressure of one of these bottles but I'm sure it wouldn't take very long to raise the pressure that much.

By the way, I really have little knowledge about nitrous (zero experience USING it), but I know a lot about pressure and temperature and phase changes with water due to my nuclear power plant backround. Just take what I say (as with anyone, especially over the internet) with a grain of salt.

Anyone notice how that guy with the sob story had about 10 advertisements on his page with so called performance enhancers "that work"?