N2O Advice please... Good and Bad!

[Anonymous]

I agree Dave.
Any ideas how I can mould a couple of Slicks?

[Dave999]

i do actually but it works out more expensive

see previous post regarding buying your own N2O factory

Dave

[db]

Here you go

http://www.moparuk.com/forums/viewtopic ... highlight=

Thanks Guy- missed that by minutes! Adrian texted me but i was stuck with the boss til it was too late- another thing to hate him for

Les- 175hp on cast pistons?

Dave- right-on dude! Just because something has become the accepted norm doesn't necessarily mean it's the best way. Most of the worlds greatest discoveries and inventions rocked established beliefs. Who here laughed at the first mobile phones? Who mocked razors with 2 blades? How many poured scorn upon milk in a 'carton'?
I rest my case

OK, here's my main issue...
Pretty much all bought kits meter at the injector. The nitrous leaving the solenoid will immediately start to gas-off/boil, mainly due to the pressure drop caused by the increase in pipe diameter from the valve to the braided hose and the fact that it's being released into an open-ended pipe. This pipe to the injector will be heated by its proximity to the motor (assisted by conduction along it's metal sheathing!), increasing the boil, this will of course vary depending on how long the engine's been running. That is until the nitrous has had it's cooling effect and reverses the effect...
The upshot of all this is that accurate reliable metering/ jetting at the injector is IMPOSSIBLE as the state of the nitrous changes from liquid to partially boiled to gas and back to liquid, BEFORE it's measured The petrol is also affected but in a different way- the instant that first 900psi blast of Bananarama! the injector, the 6psi petrol is still pushing air out of the pipe so just for the tiniest moment, pure nitrous is released.

If however, the system is jetted at the solenoids, these variables are eliminated- the state and pressure of both nitrous and fuel is a constant at that point. Once the measured liquids are released they can do what they want so long as they get into the inlet they're relative quantities cannot change. In addition, if small bore nylon pipe is used the pressure drop and heat conduction are reduced. (i know nylon is only ok up to 150-ish hp systems)
Sorry if i rambled on a bit there but if it makes sense, what do you guys make of that?

[Jon Connolly]

Have a quick look at my engine bay picture you`ll see a second solenoid on a tee piece .. this is a purging solenoid which brings a purge line into my sight from driver`s seat. Once you purge the pipe you know you have got pure nitrous ( and not a nitrous air mix ) sitting hard against the solenoid. As soon as the solenoid is opened the colomn of liquid travels a matter of a couple of centimetres only to the jet, at this stage it is still a liquid. It boils off ( atomises ) at the jet which is itself positioned a only couple of centimetres from the injection point.

What happens upstream of the solenoid is unimportant ... it is a colomn of liquid, obviously a /6 line will need more liquid than a /4 line to fill

There will be some loses downstream of the jet due to evaporative cooling of the plate but this is minimal ... probably 2 - 3 % ??? so a 150 hp shot may nett out at 145 ish hp ??

[Jon Connolly]

Forgot to add

The jet is actually housed ON the injector plate so any loses due to " evaporation " don`t matter anyway as they are just marginally cooling intake air

[Anonymous]

Take the Wizzard with a pinch of salt , if your that concerned regards the Bananarama! before the fuel then install a longer nitrous line from solinoid to plate , all the big hitters use braided hose lines , you won't see any of these nylon lines on their set ups , don't go reading to far into it.

If you do happen to go down this route then do yourself & the motor a favour & use NGK non projected type plugs , these act like a fuse & will nip a ground strap before taking a piston out , most plate kits sold will be pig rich out the box , Nos have corrected the jetting charts over the last year so these kits should be fine , any other type kit that suggests fuel pressures over 6psi & square jetting think again , the end result for these type plate kits is 5.5psi fuel pressure , 900psi bottle pressures with staggered jetting ie: 80N/70F

Aka Brutus.

[db]

Surely it's better to avoid the gassing off in the first place?
It's not so much losing 5hp or wasting 2cm of nitrous that raises an eyebrow, it's the metering of what's supposed to be a liquid!
The purge just seems such a waste and it's dealing with the problem after it's happened.
Is there a reason the likes of Nos DON'T jet at the solenoid?

I bow to your greater experience chaps and i hope i'm not winding you up here but coming from a persective of little prior knowledge, certain things just look daft to me!

Brutus- 'all the big hitters use braided hose lines, you won't see any of these nylon lines on their set ups ' - The Wiz and Burgerman both agree that nylon is ok only up to 150-ish.

From the Wos forum-
'Early last year the NHRA put our nylon pipe through their stringent tests.

They were so pleased with the results that they gave it full approval for use in their events, stating that they were extremely happy with the results. They even specified that it was ONLY our nylon pipe that they were approving.

Last night I was invited to attend a tech meeting of the SPRC it was unanimously agreed to re-word the regulations to allow our nylon hose for use on Drag cars in official UK Drag racing events.
OUR NYLON PIPE IS NOW LEGAL FOR OFFICIAL DRAG RACE USE BOTH IN THE USA & THE UK!!!!

[Jon Connolly]

[Anonymous]

DB , have a look over on 'yellow Bullet' , all the info you'll ever need is there , forget Trevor AKA the Wizzard , most kits they sell are for motorbikes or ricers using small hits up to 100 shot , go get some advice off the big hitters that know EXACTLY how it's done.

Get a decent set of rings in that motor too , moly coated rings will blister with heat/detonation , if your building this with a 250 shot in mind then think very carefully regards exhaust valve timing.

AKA Brutus.

[Nick]

Like Brutus says, search Yellow Bullet & look at their opinions on the 'Wizard of Nos'

[Anonymous]

The purge just seems such a waste and it's dealing with the problem after it's happened.
!

Imagine the scenario , bottle in the boot with a -6 nitrous line (20ft length) , the motor will be flooded with fuel BEFORE the nitrous makes it's way to the plate , not only will the cylinders be fuel rich the motor will bog off the line , this will also be the case when 'banging through the motor' without any way to purge the nitrous line , the advice given in this thread is only the tip of the ice burg , you've gotta break parts & spend sh$$t loads of money to understand the BASIC principles of nitrous run motors. ..even the best of the best scratch there head at times.

AKA Brutus

[db]

I tried to look at yellow bullet but my work laptop got upset about 'adult material'! I'll try again from home...

Won't that 20' length contain liquid nitrous from the start, held in by the solenoid or does it escape over time?

Why is the bottle kept in the boot? Next to the fuel tank! I understand the desire to have a bit of distance between you and it but the way a 1000psi bottle blows, 6 feet and a bit of thin sheet steel ain't gonna save ya!

[Anonymous]

Won't that 20' length contain liquid nitrous from the start, held in by the solenoid or does it escape over time?

!

Liquid nitrous will revert to vapour in a short space of time................leaving nitrous lines pressurised for any length of time will damage solinoid plungers & restrict flow , not good........... how do you propose releasing the pressure after a run? , ok you can remove line from bottle but that stuff gets pretty cold when sprayed over the hands/arms/face. , get over on the Bullet.

[Dave999]

well yellow bullet seems to be filled with smug Bananarama! who take the micky out of Mr wizzards unfortunate manner/attitude
he doesn't help himself either by harping on in a vaguely patronizing manner... and calling his solenoids pulsoids

if he'd just keep his mouth shut he'd do his company a service

frustrated genius or mad as a hatter? dunno

hardly balanced though is it

you will find other forums that jump to his defense.

just makes me more curious

both systems obviously work.
but he's made a big fuss about the specific heat capacity and dimensions of the pipe and fittings which is valid as far as i can tell, i mean it makes sense that materials temperature surface area colour and dimensions will change the behaviour of the liquid/gas they contain if it didn't the heat exchanger on the back of ya fridge wouldn't be ribbed and black.
but he has spoiled it a bit by perhaps exaggerating the negatives of other systems to make his point, That's like going for a job interview and spending the time you are supposed to be impressing the interviewer slagging off your last employer, it quickly wears thin and you get booted out

and it is true that you can't meter by weight a gas through a jet if you don't have control over its pressure as anyone who has tried cooking a turkey in a gas oven on Christmass day will tell ya gas mark 4 is gas mark 2 on christmas day

but do the issues he highlights occur??

Although certain posts in this thread have now been deleted i don't believe anyone was trying to prove anyone else wrong

can't be wrong if it does what ya want.... and is legal

and it only does what you want if you try some stuff out, take a bit of advice, ignore a load more, and take the odd risk.

I feel that enthusiasm to do something different, to post something different,to veer off the beaten track, is being cudgeled into the ground

so much better to try and be supported in ya quest and then maybe have to say OK it doesn't work or hey it would have been easier if.

than not try at all.

Dave

[Anonymous]

well yellow bullet seems to be filled with smug Bananarama! who
Although certain posts in this thread have now been deleted i don't believe anyone was trying to prove anyone else wrong

can't be wrong if it does what ya want.... and is legal

and it only does what you want if you try some stuff out, take a bit of advice, ignore a load more, and take the odd risk.

I feel that enthusiasm to do something different, to post something different,to veer off the beaten track, is being cudgeled into the ground

so much better to try and be supported in ya quest and then maybe have to say OK it doesn't work or hey it would have been easier if.

than not try at all.

Dave

It is a bit frustrating when trying to pass on your experience about a subject as diverse as this then to be accused of cudgoulding (how do you spell that?).
I am the first person to support anybody who is up to try an alternative and be different, but this is such a diverse subject and there are so many different ways to achieve the same goal.
When building my system and checking out the net I found so many different control methods I concluded there is no definitive method, so that design alone can screw with the grey matter and I never solved the problem of safety relating to a solenoids seizing open.
Gas suppliers will not fill bottles that are not tested and labeled correctly so using fire extinguisher bottles is a non starter unless you have them tested and labeled which is more expensive than bla bla.
Laying the bottle at the correct angle to get the internal tube to scaving the gas from the bottom of the bottle is another issue.
We even designed a turnover rig and decanted our own gas from an industrial mother bottle (@£350 if your lucky, and they will only supply commercial users.) to save money, but at £60 plus for a ten pound fill, which, if you are lucky, will give you 2 runs still works out expensive if you get it wrong.
Positioning the bottle in the boot is really an economic and space problem.
A ten pound bottle, the min size needed to get a 100hp shot, will fill the boot well in the car which means you will loose a passenger space hence they are usually placed in the boot on a road car, all the racers have them in th car to get the bottle as close to the solenoid as possible to get the best reaction time and to minimize the purge as this is wasted money, gas in the air.
However if in the car, the regulations ask for a blow down valve and tube to vent the gas to the outside in case of failure, ,that set up alone costs over £150 per bottle.
Providing a high pressure fuel feed from the boot to the engine via filters, regulators, gauges and hoses is also several hundred pounds alone.
The whole, thing gets very expensive when you add up all the elements for any system, even a DIYer using second hand parts, especially on a road car where the nitrous is only going to be used for the odd track day.
And if your insurer gets a sniff that you are using sniff they send a specialist around to kick you in the balls.
Personally, and it is only my advice "good or bad" after going there and getting the tee shirt, I would not waste my time, money and energy on a nitrous set up on anything other than a balls out race car.
I would spend my wonga ( if I had some ) on a decent stroker or turbo set up that I could use all the time on the road that would still scare you silly at the track.