So... Lets talk Nitrous!

[NOTORIOUS VR]

Alight.. my buddy wants to spray his car... with nitrous...

I know that it can be done with propane too... so what are the dis/advantages of going with nitrous? and the same for propane...

I don't know if any of you have seen where in an episode of 5th gear they took an old rabbit diesel (automatic at that) raced a NSX and it got demolished in a race (obvoiusly)... but then they equipped the rabbit with some nitrous... and it actually beat the NSX...  :lol:

So.. now my buddy wants to try it out on his TD....

Had anyone played around with this?  How much boost were u guys running?  how much fuel?  do u need more fuel if u run nitrous (like on a gasser?)....

Discuss!  

[vwmike]

Where do they show 5th gear?

Nitrous oxide is a mixture of oxygen and nitrogen with the nitrogen acting as a buffer to slow the release of the oxygen within the combustion chamber. What you're after is the oxygen. Just injecting nitrous on a gas engine will cause it to go lean, then knock...possibly bad enough to break a piston or worse. I've seen a lot of different types of nitrous related damage. In smaller amounts when properly jetted it can be fairly safe, but the biggest drawback is it's on/off nature. When the engine goes from making 100hp to 200hp in a fraction of a second it is very hard on internal engine components, the clutch, transmission, cv's, etc. A progressive nitrous controller can be used to help minimize this but by the time you've spent that much money on your nitrous system you could have turbocharged an otherwise naturally aspirated engine and you still have to fill the nitrous bottle at ~$5 a pound.

On a diesel things are a bit different. Injecting nitrous by itself isn't really going to get you anything. It would be just like turning up the boost, but not the fuel. The power comes from the fuel. You only need as much oxygen as it takes for the fuel to properly combust and keep egt's in check. I like the idea that was discussed recently with using the pressure from the nitrous system to trigger the LDA. You'd have to be careful on that one though - nitrous bottles work at a pretty high pressure.

To me, nitrous should be a last ditch effort to find more power. A turbo (or two) on your TD is going to be there and ready to go all the time without a bottle to refill or a valve to crack open when that Integra driver needs a lesson.

I'll leave someone to talk about propane who has had some experience with it.

[malone]

Got a link to that Top Gear episode? Or do you know what episode # it is? Do you recall if they stated what size shot nitrous they used and how they adjusted the fueling? I bet they cranked up fueling to the point where it would be impractical for street driving but it's only needed in a few runs against the NSX, nothing more..

Definitely need more fuel to make nitrous effective. I'll probably want to see a thick stream of smoke behind me until I hit the juice to turn every last bit of unburnt fuel into power. Some tricks will need to be done to make it a daily driver TD with relatively low smoke but gets lots of fuel on demand with nitrous. I have a few ideas.. some absurd but some thought-provoking:

1) Custom boost pin with steepest possible taper. The turbo will take advantage only part of the pin's taper (e.g. 20 PSI). 30 PSI of nitrous gas via a pressure regulator going into the LDA will push down the boost pin 100% for the additional fueling. This will likely require a stiffer spring for the boost pin.

2) Mechanically actuated max. fueling screw. Stops throttle lever at e.g. 75% during normal driving. When nitrous is ready, max fuel screw is retracted so the throttle lever can swing 100%.

3) edit: Scratched this one...

[vwmike]

I'm thinking the wet shot would be a disaster. The engine would just preignite the fuel.

[BlackTieTD]

i've read a little on it before but that was a long time ago....what are the benefits and drawbacks of using propane? anyone here have any first-hand experience? more interested in that than nitrous.

there are companies like this one offering kits for the american cars, could be adapted...a better one could be built...:

The Powershot is an infinitely variable-stage vapor injection system. It is controlled, activated and proportionate to the boost pressure of the engine. The Powershot comes on slow and steady and as the boost increases, so does the flow of propane. More boost=more propane=more power! It is fully adjustable and can be customized for your specific application in minutes for towing, performance or mileage gains.

[vwmike]

I also have this slight concern when driving around with a tank full of propane. If you get hit hard enough that could result in a rather large explosion.

[malone]

Fact: The suicide car bombers in Iraq are VW diesel owners with propane tanks in their trunks. Has anyone seen pictures w/ a big crater in the middle of the road? :lol:

[NOTORIOUS VR]

Awsome... so let's keep this going...

The episode is 5th Gear 2004 5x3.... It used to be available from the torrent sites to DL... and http://finalgear.com used to have it available as well, but no more...

I believe I still have it somehwere... or at laest my buddy does... so I'll see if I can host it somewhere for u guys when I find it...

As for the nitrous injection part... I know how it works... I"ve been and worked on enough of it with gassers... I was just wondering about the diesel application...

EIther way, I guess that w/o the extra fuel at the time of the ijection it's not even worth the effort....

But I'd like to se what comes of this thread, even if me move more towards propane injection (dangerous or not )

[BlackTieTD]

anyone know of any camping vehicles that are equipped with propane, and diesel powered?  :lol:

[wyldman]

Propane works well on a diesel if properly set up.Power is increased,as well as mileage,with a minimal EGT increase.Propane tanks onboard shouldn't really be a worry.There are lots of propane vehicles driving around,and they aren't blowing up all the time.

It must be injected with boost,and at higher RPM's,or pre-ingnition occurs,which can be damaging.Cylinder pressures and temperatures also tend to get quite high if too much is used,or at too low an RPM.Headgaskets failure is common when this happens.A  hobbs switch is used to open the propane valve at a preset boost level.

The other problem with propane is getting the right tank.Most cheap BBQ tanks are setup to draw vapour,which is not what you want.You need a liquid draw tank,and then the vapourizing is done up at the engine.Flow is much easier to regulate this way.

Nitrous is fairly safe as well,as long as it's injected at the correct time.Too early,with too much fuel sends cylinder pressures skyrocketing.A lot of guys use it to help spool the turbo(s) at low RPM,but you have to be very careful doing it.At higher RPM's it is great to supplement increased fueling with a smaller turbo.You do need extra fuel or the nitrous alone does nothing.

I have run propane on my Cummins Turbo diesel,but have removed it in favour of other mods.I did have problem running a vapour system,and didn't wany to buy a dedicated liquid draw tank setup.

[Dr. Diesel]

nitrous is great with a diesel. With a mild jet, you can fire it right off idle, resulting in immediate turbo spoolup, and a pair of tires that won't weigh as much as they did a few minutes earlier. A larger jet used only at higher rpm helps out on the big end. I never did any more than turn the fuel screw in a touch so it was quite smokey at full throttle/full boost. N2O on, no smoke, loads of power. Dry system only. Ideally, you'd have two solenoids, and two jets; one small, one big. Small jet fires at low rpm, and big clicks on at higher rpm, and a device to supplement the LDA.
Filling the bottle is a mild annoyance, especially when your local guy (PERFORMANCE CELLAR, GOBBLER OF MALE CHICKENS) rips you off, but it's very worth it. VERY.... worth it. Be gentle and start small. If you hear any weird noises (you'll know when you hear it) go back down a jet size, or up 500 hundred rpm.
As a comparison, my old 1.6L w/good exhaust, Giles pump N2O and 25 psi made mincemeat out of a modded 351 mustang II.

oh, and bite the bullet and buy a remote bottle opener. Nothing kills a buzz quite like being next to a Type R at a red light... but your bottle is closed.

[Northboundtrain]

Here's something I'd like to try.  

http://www.duramax.bizhosting.com/My_Truck/water_injection.htm

The GM 6.5 is IDI, so I'd imagine that this mod would work well for our engines as well.  I wonder how water mist would work on an NA engine.  (I'm still on the holy grail TD quest).

[fspGTD]

Don't bother wasting your time with propane fumigation on an IDI VW Diesel.  It detonates far too readily in our convoluted combustion chambers.  At the low fumigation quantities where engine-destroying detonation doesn't occur with it, it won't add much if any over 5% to the engine's power.

Been there, done that...  Here is an old engine compartment shot of the trick LPG fumigation system I made:

The truth is I never was able to get the propane to work well to ever recommend it to anyone else who has an IDI diesel.  I hear they work great on DI diesels through.

If you must fumigate in an IDI, try compressed natural gas!  It's got a much higher octane than propane, so should be good to resist detonation under higher fumigation quantities (which should enable it to add more power :twisted: )

Only problem with CNG is, I haven't found a reasonably sized automotive CNG container anywhere.  All the ones I have seen are generally massive.

[DVST8R]

Okay two things: Nobody has touched on.

1. Propane is a fuel.

2. Nitrous is an oxidizor.

There for if you are underfueled and add propane you will get more power, however in our extremely high CR idi's not much b4 detonation will occur. If you are over fueled and add nitrous you will get more power, as it will be like adding a bigger turbo (more air). If you do the opposite in either case you get nothing, well if you are overfueld and you add propane you still get the detonaiton.  :wink:

Okay I have read some other things that in my experiance with diesels are wrong.

- Even a monster shot of nitrous in a well overfueled diesel does NOT create the same "kick" as in a gasser, ie no huge shock loads to the drivetrain. More of a linear rush, the first time I tried nitrous in a diesel I was like braseing for a big hit and it was rather dissapointing (the hit that is not the rush)

Next point in a diesel with a low enough CR to handle propane nitrous and propane can be used in conjunction for more power in a motor that is not overfueld during normal use.

Next a progressive controler is great for running nitrous on a diesel as you dont even run a jet, you just run open soloniods and let the contorller set the amount, however they are pricy.

Finally the only real way to tune a nitrous setup is at the track. You keep adding bigger jets till you run slower and then you go back to the size you ran the quickest with. Just guessing is not even close to a good way to do it and just because jet "A" worked well for someone means nothing for your car as everything is different. IMHO dyno's dont work well for setting up nitrous either but that is an opinion for another day :roll:

I think this covers it for now.


Oh Jake, I found a bottle for CNG that would work for our apps, but it is like $1000. Didnt seam worth it. Some one was saying that you could convert a nitrous bottle or a scuba tank though...

[wyldman]

Here's something I'd like to try.  

http://www.duramax.bizhosting.com/My_Truck/water_injection.htm

The GM 6.5 is IDI, so I'd imagine that this mod would work well for our engines as well.  I wonder how water mist would work on an NA engine.  (I'm still on the holy grail TD quest).

My experience with water (and water\meth) injection,is it needs to be injected under boost,and injected under pressure.Without a turbo,you have no boost.I'm not sure how it would work.I think  you would need higher water injection pressures,with nozzles very close to the intake ports so the water stays vaporized.