M10 NOS... Somebody asked if it had been done.

[Somchai]

From 'Wizards of NOS'

Why Not Pure Oxygen?

The simple and most relevant answer is because we couldn't get enough into the engine for it to be as effective as nitrous oxide. Air has only 23.6% oxygen by weight, the rest is made up largely of nitrogen. Although nitrogen does not aid the actual combustion process it does absorb heat, as well as damping what would otherwise be a violent explosion, rather than a controlled burn. When you add nitrous, it has 36% oxygen with the rest being nitrogen. So the more nitrous oxide you add, the less percentage of nitrogen is available to absorb heat. That's one of the reasons why adding more nitrous increases the heat of combustion very rapidly. If we were to add pure oxygen (which has been tried), the percentage of nitrogen would progressively decline to a much greater degree than with nitrous, as more and more oxygen was added. Consequently an engine wouldn't be able to handle much pure oxygen before the increase in heat lowered the detonation level to unusable levels. Furthermore, oxygen can only be 'readily' stored in a compressed 'gaseous' form, without being stored in a special cryogenic thermos cylinder (a cylinder within a cylinder with a vacuum between the two walls) and as a gas it loses the cooling effect that nitrous offers by being available as a liquid. Adding the oxidiser as gaseous oxygen would displace more air than adding nitrous in liquid form, resulting in a lower total power capability. In other words; by using nitrous oxide we can squeeze in more oxygen atoms in a more beneficial form, containing substantial amounts of detonation suppressing nitrogen, than would be the case with gaseous oxygen.

[Cyclone101]

From 'Wizards of NOS'

Why Not Pure Oxygen?

The simple and most relevant answer is because we couldn't get enough into the engine for it to be as effective as nitrous oxide. Air has only 23.6% oxygen by weight, the rest is made up largely of nitrogen. Although nitrogen does not aid the actual combustion process it does absorb heat, as well as damping what would otherwise be a violent explosion, rather than a controlled burn. When you add nitrous, it has 36% oxygen with the rest being nitrogen. So the more nitrous oxide you add, the less percentage of nitrogen is available to absorb heat. That's one of the reasons why adding more nitrous increases the heat of combustion very rapidly. If we were to add pure oxygen (which has been tried), the percentage of nitrogen would progressively decline to a much greater degree than with nitrous, as more and more oxygen was added. Consequently an engine wouldn't be able to handle much pure oxygen before the increase in heat lowered the detonation level to unusable levels. Furthermore, oxygen can only be 'readily' stored in a compressed 'gaseous' form, without being stored in a special cryogenic thermos cylinder (a cylinder within a cylinder with a vacuum between the two walls) and as a gas it loses the cooling effect that nitrous offers by being available as a liquid. Adding the oxidiser as gaseous oxygen would displace more air than adding nitrous in liquid form, resulting in a lower total power capability. In other words; by using nitrous oxide we can squeeze in more oxygen atoms in a more beneficial form, containing substantial amounts of detonation suppressing nitrogen, than would be the case with gaseous oxygen.

Accurately explained from a thermodynamic perspective.

[flyingjolly]

What the OP is showing is referred to as a 'wet nitros' system.

This means additional fuel is also injected along with the nitros.

There will be 8 lines in total going to the inlet ports. 4 carry the nitros and the remaining 4 are hooked up to the fuel pump. Both sets of lines are solenoid controlled to open (usually at full throttle)

Fuel injected cars can just run nitros lines and be mapped to increase fuel delivery as required.

Oh sure! thanks! i truly forgot that over the years.

[Simeon]

Thanks for the reply, I appreciate it.

That makes sense (even if I got the percentages of oxygen wrong!)

[dondmar]

Don't forget the most important part about this, IT'S COOL AS SHIT! forget horsepower and what not, that's not the entire point.

[NickVyse]

Don't forget the most important part about this, IT'S COOL AS SHIT! forget horsepower and what not, that's not the entire point.

Only when activated by a hidden red button on the gear stick ;-)

[roadhog0]

I'd almost be afraid to hit the NOS button!

[oldguy]

Been there, done that over 8years ago.. Used the high speed timing retard on my Mallory box to take timing out when it was engaged. Do put a WOT switch on it

[midnightmotorsport]

I'm enjoying the good info being spread here, so here's the rundown:

Yes, it is a wet shot. Fuel and nitrous both through NOS Soft Plume 90 degree fogger nozzles. Both the fuel and nitrous are metered by jets or "pills" in the nozzles, so you jet just like a carb. Bigger N20 jet adds air, bigger fuel jet adds fuel.

The goal of the build was proof-of-concept, safety, and reliability. The motor is 9.5:1 pistons, heavily decked head (probably closer to 10:1 comp now), IE oversize stainless valves, TEP 294 cam, dual valve springs, ported, polished, header, exhaust, DCOE 45's, TWM air horns, blah blah blah, etc. All the normal good stuff. Currently running the smallest jets available (should be about 6hp/cylinder gain for about a 25 shot total), and runs GREAT. Motor sounds healthy as hell, pulls nicely faster from 4k-6.5k rpm (when I let off). Feels like a bigger cam, or VTEC kicking in. Have bigger jets waiting in the wings, and can't wait.

In the name of safety, the nitrous has a master arm switch, a full throttle switch, and a button. The system must be armed, I have to be at WOT, and only then the button will activate the injection solenoids. I would really like to add an RPM window switch (3500 to 6500 rpm or so) but they are bloody expensive and not strictly necessary.

Also for safety and reliability, I am running a Crane Cams TRC-2 switched timing retard controller attached to my Crane HI-6 ignition system. It automatically retards timing an adjustable amount when the nitrous is activated. Currently running about 3-4 degrees retard with the juice. Probably being conservative, but there's always room for tweaking.

Because I am running a VERY high capacity Holley fuel pump, fuel for the wet shot is just tapped from my normal carb feed line. Auto Meter Sport-Comp electric fuel pressure, nitrous pressure, and narrowband air/fuel gauges live in the A-pillar pod and keep an eye on things related to fire. Oil pressure/oil temp gauges were already installed, and I wouldn't run without them.

For cool factor, there is a purge nozzle in the RH factory windshield washer location. Very cool nitrous plume. The system is wired so that with main power on, the blue button on the steering wheel activates the purge solenoid (yellow LED next to the button illuminated), and when armed by the full throttle switch (red LED illuminated) the button switches to activate the injection solenoids and the timing retard. That way, if I come off the throttle, not only do I get the LED warning, but also the purge plume as a very obvious warning sign. Also for cool factor, next to the main power switch there is a sight glass indicator from an old fighter-bomber that flips "ON" when in purge mode, and "ARM" when at WOT, ready to inject (thanks Jon!).

I can't state enough how happy the motor is with this little shot! I have a very VERY intimate history with this engine, and know it like the back of my hand. It LOVES the nitrous. I can't wait to play with the larger jets. Currently I have just used the narrowband O2 for quick-and-dirty tuning of the nitrous/fuel mixture, but bigger shots will be tuned in with the wideband I keep in the shop for customer carb tuning.

I am about $1k into parts for the setup (even with some bargain hunting), but as people around here know, I don't half-ass anything. All NOS brand parts, Aeroquip -an fittings and braided stainless lines, Cunifer cupro-nickel hard lines, Auto Meter electric stepper motor gauges (stupid things were about $200 each), etc, etc. Do it right or don't do it at all. If you were to buy everything brand new out of a catalog, you'd be between $1500 and $2000 into these same parts. Still, it only costs $40-$50 to fill the 10lb bottle, so it's not too bad to maintain that cost. Also, given that you can just re-jet up to a 50hp, 60hp, or beyond, cost-per-hp actually works out pretty reasonably compared to our other options for the same power gains.

Certainly if you are starting out with a built NA motor and want to add even more power, it's a great option. With my motor, to make the same power gains I would have had to go very extreme with the cam, or compression, or tear it all down and start from scratch with a low-comp turbo setup. So the nitrous fits its niche pretty well.

Moral of the story: ignore the nay-sayers. Modern technology has made tuning a nitrous system safe and reliable. It may not provide the same constant presence as a turbo, but it does exactly what nitrous is supposed to do: it puts a shit-eating grin on your face.

[AceAndrew]

Patrick, you're crazy. In fact I've thought of a decent character for you....

IT LLLLIIIIIVVVVEEESSSS!

[oldguy]

I ran a 75 shot with 10 degrees of retard. Ignore the haters... Eat life!

I've got an old dynotune square nitrous air fuel safety switch if your interested. fits right in one of the heater vent controls on the dash

[BlindRhino]

Oh great, I am riding with David and just the extra added weight of me in David's car will put us in the rear of the pack to try to keep up with your monster Patrick, for Houligan's day drive, uh, I mean the nice gentle drive around Seattle on Saturday to soak in the sun which has finally shown it self this year...yeah, that's it. See you guys at the shop so we can drool over this latest creation by the resident mad scientist before the drive.

[jgerock]

Doesn't really matter how you spell it or what brand you used it is kick ass all the way! I thinks it's funny that the guy from Arkansas is worried about spelling...

Take it easy Doug. Skip is a very knowledgeable guy who has his own shop.

[TobyB]

IT'S COOL AS SHIT!

...until you have to lash the valves...

heee.

Yes, I WAS always the kid who pissed in the pool. Why do you ask?

Patrick, that's fantastic.

I'm just jealous.

t

[skipsfcr]

Thanks Jim...If Doug from Oregon had read a bit more closely he'd have understood the spelling reference was in regard to my own inability to change my computer's font to properly symbolize "N2O". And while I'm most certainly not politically correct, it is in extremely bad taste to make sweeping generalizations regarding the geographical location from which one comes. We's plenty literate down here!