NITROUS OXIDE ( nos / n2o ) advice forum

I am looking to fit NOS to my turbo charged 1.6 CVH engine currently running around 200wbhp, and after searching around on here it seems that the target AFR when using NOS is pretty much the same (maybe a little richer) as normal, which in my case is 11.8:1 - 12.1:1 full load WOT, I just wanted to check this is the case?


My management has two stage NOS control so enrichment will be done using my normal injectors, triggers are TPS, CLT, RPM (lower & upper), and an arming switch that I will fit to the dash.

What will I need to build my system please?

Very quick shopping list from a look on the WON site...
Bottle @ Valve
4 NOS Injectors
1 NOS Pulsoid
Plumbing & Wiring

Thanks!
Karl

Thanks for the reply, would you mind explaining why using a wet system is better than using my existing injectors?
The SB150i only uses a single injector and i'd prefer direct port for more accurate distribution across all 4 cylinders.

Thanks,
Karl.

There are NUMEROUS reasons why wet is better than dry (haven't got time to list them at present but will try and make time later), so for now I'll say this;
The car in this link is probably our most successful turbo customer.
It is FULLY supported by Motec's tech team
If anyone knows how to get the best from a dry nitrous system it is Motec but as you can see they decided to use a wet system on this car for ALL the reasons I'll try and get back to list for you later.

If they chose not to use dry, you can be sure that WET IS BEST.

On a turbo both single and direct port can work very well, so the choice is yours and if you want direct port then it's our;

http://www.noswizard.com/product_desc.php?id=58

that you need.

With a bit of luck some of our regular forum members will drop by and tell you some of the reasons why WET is better than dry but if not I'll be back ASAP.

BTW the MAJORITY of ALL my TOP turbo customers use WET but we do also have some that use dry, however the reason some people do so well with dry, is because they are in a better position than most to overcome the problems of using dry.

Thanks again!
I look forward to reading the differences/problems with using a dry setup.

Karl.

Here we go;

1) Although a dry system APPEARS to be a cheaper option (due to fewer parts), when it comes down to getting the end result it is the dry system which ends up being FAR MORE EXPENSIVE than a wet system.

2) With a wet system you are provided with EVERYTHING you need to make extra power THE SECOND AFTER the system is fitted. With a dry system you have to source additional components (most of which add much more to the cost of the system than the difference in the price of the wet V's dry kit price) and when you've managed that, you MUST SPEND HOURS working out how much additional fuel will be needed and then even more hours on a dyno or on the road with a laptop, feeding that information in to the ECU and testing it, followed by adjustments and even more testing.

3) A 'WON' wet system can be fitted by a novice and set up by a novice without the need for an expert or a dyno and a good end result is GUARANTEED but a dry system requires not only a nitrous expert to provide the nitrous flow figures but also an fuel injection expert to take that info and translate it in to the required incremental increases in fuel delivery through the injectors.

4) A dry system DEMANDS that the fuel injectors are in perfect working order, are perfectly matched for flow and can flow the additional fuel under all high load engine conditions - a wet system does not.

5) Assuming perfectly matched flow from the injectors, it is not always possible to get perfectly matched nitrous flow to all cylinders and as the 2 media (fuel and nitrous) are not controlled by the same system, it is very difficult to address such problems.

6) Assuming everything is done correctly and none of the above issues cause problems, a dry system (assuming the injectors have been increased to accommodate the extra fuel demand), will result in lumpy idle and worse fuel economy, as bigger injectors are less responsive at low throttle openings.

7) If you encounter ANY problems with a wet system, you only need contact me and I'll solve them - PERIOD!!! However, if have a dry system I can only assist you with half the potential problems.

Dry systems are fine for those with the appropriate expertise, with the appropriate equipment, with money to waste and who think they can manage without my assistance. If you feel you fit in to this category then I'll be happy to supply you with a dry system, otherwise I'd strongly advise you to buy our wet system.

For better or worse yes I think I do! lol

I see what you are doing and that is trying to prevent people destroying their engine and then blaming it on NOS, when in reality it is their lack of knowledge/experience that has caused the failure, which I understand and is a good idea!

But I am confident I can fit the sytem and map the needed fuelling and timing to ensure my engine perfroms reliably.

Thanks for your time and help!

Karl.

Cheers!

Yes I already have standalone management, large enough injectors and fuel pump.
I do indeed plan on guessing a rich starting point and was going to retard the timing 8 degrees to be as safe as possible, my next question was going to be very roughly how much should I increase my fuelling by 25% 50% 75%? I've read NOS has 36% Oxygen and air has 21% Oxygen per given volume so I would guess maybe 25% would be a safe starting point and gradually lean out and advance the timing to my target AFR whilst monitoring for Det?
Oh just to add I was thinking of starting out with a 50bhp shot of NOS.

Thanks,
Karl.

No one have any thoughts on the above post?

Thanks,
Karl.

Thanks again Trev!

It does look like it's a 'On my own head be it' situation... but I look forward to the challenge!
If you could tell me in CC/s that would be great!

Another thing that I thought of is that at 27psi of MAP the flow rate of your NOS jets is going to be reduced compared to at atmosphere or vacuum so thats another factor for me to bear in mind.
In fact thinking about it because they are a fixed flow the % of NOS at low RPM/MAP will be much greater than at high RPM/MAP, will that not give me a big kick in BHP to start and then gradually reduce as RPM/MAP increases?
Perhaps a progressive controller might be beneficial?!

Karl.

Cheers!

I was talking about the NOS being injected against MAP reducing NOS flow at high boost and rpm not fuel

How does a progressive controller work, does it control PW to the Pulsoid?

Karl.

Ok thats cool, thanks.

So if i knock myself up a little controller that once triggered gradually increases PW to the Pulsoid from 20%-80% over a adjustable period of time (say 1-5 seconds) that will give me a smoother torque curve which is good because big torque spikes just induce wheelspin and put extra strain on the drive train!

Thanks for all your help!

Karl.

Easier said than done just as your dry option is but if you like a challenge then you're about to take on a couple of big ones.

For the record we have been designing and building progressive controllers longer than any other company in the world (going on for 20 years or so) and we're still trying to overcome 'issues' that such a product produces but at least you only have to make it work correctly on 1 car and not ALL cars and bikes, so that will make it a 'little' easier.

Yeah I'm really looking forward to getting stuck in!

After some more thinking I may be able to get a 'controller' built in to my ECU, as it works in the same way as an idle control valve, I already have a high load transistor to turn it on so would just need a PW vs Time table to vary the 'On' time from say 0% to 100% for full control!
Alternatively a simple 4 or 5 stage controller (say 25% 50% 75% 100% over 4 seconds) is very easy to do if I struggle with a fully interpolated external one.

Karl

Karl, this is sounding very interesting.

I suspect even Trev, who is cautious if dry systems for all the best reasons as a result of his experience (and acute awareness of the failures of inferior systems), will be very interested in the results if somebody with the right knowledge and facilities manages to develop a modified ECU to do all this!

FYI Lawson we do already have a number of customers who have done (and some that are currently doing) the same kind of thing but they are usually companies who have all the necessary facilities at their disposal, like Motec, etc.

I've also had customers with lesser facilities fail in their attempts to take this route and/or who have decided that wet is the easier/better route.

In the case of the Motec/RC Motorsport system, they decided against dry and fitted one of our wet systems but use an extensive range of ECU control that would normally be used for dry systems to control not only the delivery but also the mixture and as you'd expect, the timing.
The control is so extensive that it even relies on GPS location on the track (as well as all the other desired parameters like gear selection, rpm, boost, throttle position, etc.) to determine how much nitrous is delivered and when.

It's always nice to see a privateer trying to push the boundaries though!

When my dyno is up and running I intend to do some experimenting with bike systems to see what can be achieved with custom Power Commander maps, but that's another story . . .

I'll be holding you to that one Trev, many thanks!

The end result will be well worth the effort!.... Have a little faith lol

The way I see it, is that I've spent the past 35 years doing all the HARD work and taken all the risks, so that my customers can have the immediate pleasure that nitrous offers, without the highly potential risks that are otherwise inevitable with nitrous and the consequential hard and expensive repair work that can often cause.

However, I do understand how some people find 'a challenge' more enjoyable than the end result of the achievement, no matter what the expense and risk, as I'm probably the epitome of that philosophy.