NOS Schematic

[Slimshady]

Ok, I have dabbled a bit with pneumatic schematics and now have a wild urge to NOS my bitch up – not a lot just 25 – 75 BHP would do without leaning her out too much.

I enclose a PDF of my ideal NOS system but I do have a couple of questions for all you NOSer’s out there.

In air terms, I totally understand the system up to the solenoids but from then on I don’t have a tube of glue.

If anyone can answer any of the questions below, I would love to hear from you:

1) What is the typical max pressure of NOS in a full tank?

2) Would standard pneumatic valves (Festo or SMC for example) withstand the pressure, liquid flow and cold temperature of NOS?

3) Would air push fittings withstand NOS? (note dependant on Q1)

4) What size feed would the injectors require? Obviously this would determine the pipe sizes down the system.

5) Are the NOS solenoids similar to poppet valves, 3/2 high speed acting valves, and how do you supply the electrical feed, i.e. from the coils, a 555 chip or are they always on when the button is pushed.

6) How do you connect the NOS to the cylinders?


Sorry for all the questions I simply want to work out if it’s more cost effective sourcing the parts for myself?

Thanks in advance


Slim

[orionn2o]

ok I don't know loads about pneumatic bits but i can answer some bits.

1. A full tank of NOS will be around 1000 - 1200 psi.
2-4 . don't know
5. Its up to you how you want to connect but in previous systems i've had a full unpulsed shot which is activated on full throttle. So you have an overal arming switch and then when you floor the car the nitrous kicks in. Pulsing is a slightly more complicated game but as an example Wizard of NOS pulsoids can be pulsed at up to 50hz as far as I remember, (if you email them they will give you an exact figure)
6. Assuming you mean engine cylinders, you have 2 methods with the most common being you spray and mixture of nitrous and fuel (approx ratio of 2 - 1) down the air intake and the gas is sucked into the cylinders with the other outside air.
OR you can have a direct port system but will need to be drilling holes and stuff which is usually for the more advanced people

[Eurospec]

All i would say is in my oppinion it is very much worth the investment in a window switch, and if possible use a tps trigger rather than just a micro switch- though the latter is very much a prefferance thing about how and when you want the NOS to come in.

This will let you have the Nos activate when:-
Our overall system switch is on
Your throttle position is over a certain % (say 90%)
Your RPM is between X and Y Rpm

For example on an 8000rpm limiter, i would set the window as 3000 to 7000.

The reason being that if you miss a gear (realise many of these cars are tips, but bear with me a sec) and punch the gas again the Nos will get you to the limiter in no time. If you have no window switch to kill the nos off then the rpms will shoot up to the limiter, the ecu will kill the fuel but the NOS will keep going! This can result in an engine meltingly lean condition at high rpm, and for me i just dont wanna go there!

The same would apply if in a tip you hit the rev limiter in tip mode, the nos will keep going but the car's normal fuel system wont.

Similarly, firing nos into a heavily loaded (like labouring in a high gear at low rpm) engine is not going to be good and isnt going to help det. For that reason i fire it in higher.

The TPS switch thing is pure personal preference i set them at 90% for drag cars so that the nos s hitting just as you floor it, giving a fractionally faster response. A micro switch on the throttle is fine really. It also ensures that the Nos is off as the throttle shuts. I have seen cars blow the intake pipework off from nos backfires caused by nos piling up on the throttle plate due to s stuck or missaligned micro switch.

Cheers,

Ben.

[orionn2o]

what you really want is a pulsing controller that sets an amount depending upon RPM.. like the one im designing

[Wodjno]

I have 2 x NOS kits(New) :2thumbsup 35/50/75 bhp

PM me if you are interested :happy:

[Slimshady]

Firstly thanks for your help chaps:

Orionn2o – 1200 PSI seems either too high or on the edge for a lot of pneumatic systems – I need to do more research into the pressures involved on the hardware but with pressures as high as that I would be worried about the safety of the system.

Info on the pulsoids has also helped out – as you explain the timing appears to be based on pulsing the valve rather than timing with the engine.

Benh – thanks for the advice, I was actually thinking about using the main valve as a prime i.e. switch on dash to arm the system then a push button on the steering wheel to inject the NOS at the users discretion, but after the excellent advice I think the window would probably be a more practical and safe solution

Wodjno – Thanks for the offer – I am interested but I think I can obtain most of the components through work, a lot cheaper than a full system, but you are more than welcome to PM me a quote for one of your systems.

Thanks again

Slim

[mart0398]

Wouldnt the NoS bottles have requlators on them to drop the pressure as soon as it comes out of the bottle, either a variable one like on an Argoshield bottle for welding or a fixed regulator like used on Propane cylinders?

[Eurospec]

There is no regulator normally, just a bottle with a saftey valve on it.

This is why you get people using bottle heaters in order to regulate the pressure of NOS they have.

Cheers,

Ben.

[zentac]

ok I don't know loads about pneumatic bits but i can answer some bits.

1. A full tank of NOS will be around 1000 - 1200 psi.


Nah... bottle heaters hold the pressure at 950psi

[Slimshady]

Wouldnt the NoS bottles have requlators on them to drop the pressure as soon as it comes out of the bottle, either a variable one like on an Argoshield bottle for welding or a fixed regulator like used on Propane cylinders?


Yes you are totally correct I left the regulators off primarily because I don’t know what pressure a full bottle has and what pressure is required when injecting into the chamber. When I look at photos of NOS kits I can not see regulators so I presume full pressure is required, or the regulation it done in the valve / solenoid valves – max flow rate of the units.

I also considered adjustable flow restrictors just before mixing it in with the fuel, simply so you get a ramp up rather than a big kick and ultimately traction loss. The down side would be the setup, if you don’t get them all singing the same tune you will experience unequal ramp up pressures over the cylinders until the system reaches max pressure.

I am still puzzled why some of the NOS kit suppliers use plastic line similar to that found with pneumatic systems - Festo and SMC. If indeed this is correct what type of connections do they use i.e. push in fittings or what – for this type of line I only know of push in fittings.

Yours still baffled /help


Slim