NITROUS OXIDE ( nos / n2o ) advice forum

I decided I’d start a thread to deal with the issue of STRESS, as it seems most people who ‘THINK’ they know all they need to know to challenge me on this subject, need a THOROUGH LESSON to show how LITTLE THEY REALLY ‘KNOW’.

SIMPLE FACT 1;

It is OBVIOUSLY TRUE that adding nitrous oxide to an engine via an incorrectly designed kit, that has been fitted incorrectly and/or is used incorrectly and/or has NOT been setup/tuned correctly WILL ADD STRESS to an engine.

SIMPLE FACT 2;

I have 100s of thousands of customers using MY systems and NOT A SINGLE customer who has followed my instructions correctly, has ever damaged a single engine component, DESPITE A LARGE PERCENTAGE OF THEM having increased the power by as much as 100%.

SIMPLE QUESTION 1;

If nitrous oxide is supplied to an engine by a CORRECTLY designed system, that has been fitted correct, which is then set up/tuned correctly and is then used correctly, adds stress to the engine in the magnitude such ill informed people believe it does, then how come the 100s of thousands of customers using MY systems DO NOT BREAK ANY PARTS!?!?!?!?

SIMPLE ANSWER 1;

MY systems do NOT increase stress AT ALL or at very least to anywhere near the magnitude, such ill informed people expect.

SIMPLE QUESTIONS 2;

What happens to power and therefore the load and stress, if the timing is retarded on a NA engine?

SIMPLE ANSWER 1;

If you retard the timing on a NA engine the power falls and therefore so does the load and stress on the engine.

MORE SIMPLE FACTS;

1) Adding nitrous to an engine increases the combustion speed, therefore without retarding the timing by an appropriate amount, the PEAK LOAD on the engine WILL increase but that does not necessarily mean the stress will also increase.

2) By RETARDING the timing, it is possible to reduce the PEAK load on the engine and therefore any increase in stress.

3) UNLIKE a NA engine, a UNIQUE quality of a nitrous injection engine, is that excessively retarding the timing, DOES NOT CAUSE a total loss of performance.

4) By EXCESSIVELY retarding the timing, IT IS POSSIBLE with a nitrous engine to actually REDUCE the PEAK load/stress on the engine components (even below that of NA), whilst still making MORE MEAN POWER.

5) For anyone who doesn’t understand how this is possible, allow me to explain;
i) Combustion chamber pressure rises are EXPONENTIAL in the extreme and as a consequence, PEAK combustion pressure ONLY occurs for a fraction of a second
ii) The value it reaches depends on a number of factors, the amount of combustion charge, engine speed, ignition timing.
iii) Overly advanced timing results in extreme, undesirable PEAK pressures
iv) The pressure AFTER PEAK pressure is always in decline
v) By filling the combustion chamber with more charge and then firing it later than optimum, such high PEAK pressures can be AVOIDED but because there is much more expanding exhaust gases, the MEAN pressure is HIGHER, which results in a higher pressure from the point of PEAK pressure onwards, despite that pressure being in DECLINE. The result is an increased push on the piston for a longer period of time, before they exit the exhaust valve.

6) Whilst we are making more power it is NOT AN UNAVOIDABLE CONSEQUENCE that more stress is generated, DUE TO the way that increased force is generated/applied.

7) Even without the timing corrected the engine is subjected to less stress than normal (or at worst ONLY MARGINALLY more), as a consequence of the difference between the combustion process NA and how it’s changed by adding nitrous.

8) Without nitrous the NA combustion process is akin to hitting the piston with a sharp blow from a hammer, because there is minimal charge in the cylinder (compared to a nitrous charge) and therefore the combustion process is short and sharp, like a hammer blow.

9) However, although the burn rate is quicker when nitrous is added, there is much more to burn, so the process takes longer overall and so it acts more like a SUSTAINED PUSH on the piston, rather than a blow from a hammer.

10) Surprising for most people, without nitrous the cycle of pressure/force changes within the engine are extreme in comparison with those when nitrous is added. Rather than the sharp rises and falls in pressures/forces within a NA engine, a nitrous engine sees more SUSTAINED and more prolonged changes, which is MUCH KINDER to the engine components than NA.

11) The best example I witnessed of that was on a motorcycle I was dyno testing some years ago. The bike had a very long chain run and when doing a full power run NA the chain was whipping about like something deranged. However, when the same power run was carried out USING NITROUS, the chain stayed PERFECTLY STRAIGHT WITH NOT A SINGLE IRREGULARITY!!!!

12) This PROVED to me that the NA combustion process was like the piston being BRIEFLY HIT by a hammer, while the nitrous combustion was more like a MORE SUSTAINED PUSH on the piston

13) The load/stress on engine components rises EXPONENTIALLY as rpm rises, for anyone who doesn’t understand what ‘exponential’ means, here is an example of an exponential rise rate;
1 – 2 – 4 – 8 – 16 – 32 – 64 etc. etc.
The load on the engine (in particular the piston/con rod) might be as follows;
At 1,000 rpm = 1 unit of load/stress
At 2,000 rpm = 2 units
At 3,000 rpm = 4 units
At 4,000 rpm = 8 units
At 5,000 rpm = 16 units
Etc.

14) This means that you could increase the power by say 50 hp at say 1,000 rpm and it could create less load/stress than the same engine running at say 2,000 rpm WITHOUT the 50 hp increase.

15) When tuning NA to achieve substantial power increases it is UNAVOIDABLE to do so without increasing the peak rpm of the engine, which INEVITABLY results in HUGE increases in load/stress.

16) With nitrous you DO NOT NEED to use even ONE rpm more to increase the power of the engine, therefore for an equivalent increase in power (say 50 hp), a NA engine will be subjected to MUCH HIGHER loads and stresses than a nitrous engine.

17) Furthermore it is ACTUALLY ADVISABLE to use nitrous over the LOWER rpm range, because it is more effective then, as each induction cycle is longer and therefore more nitrous gets in to the cylinder per stroke, which results in a HUGE increase in torque.

18) Even using the normal peak rpm shift point is unadvisable, as using a lower rpm shift point results in quicker acceleration, because more time is spent using the higher torque output generated at the lower rpm, that the engine drops to after a lower peak rpm shift.

19) As RPM rises, less and less nitrous enters the engine per cycle, therefore reducing the load on the engine when inertia loadings are naturally increasing

20) Inertia loadings are the main cause of component failure

21) The combination of maximum effect (torque) being generated at the lowest rpm and the fact that inertial loadings rise exponentially as rpm rises, in conjunction with short shifting (as I always recommend), means that it’s not only possible NOT to increase the load on an engine when adding 50 hp of nitrous but it’s also possible to REDUCE the load below that on a NA engine whilst still achieving an increase in performance.

22) The perfect example of that is the latest Audi V8 engines which started suffering component failure due to excessive inertia loadings just before they were released on the market. To overcome the problem, they lowered the rev limiter by a few 100 rpm but this still left them close to the limits of what was reliable. However, despite that being the case, we have added in excess of 100 hp worth of nitrous and by advising customers to cut the nitrous off or shift 500 to 1,000 rpm earlier than normal peak rpm, those customers continue to have TOTAL RELIABILITY.

23) The more intake charge you feed to an engine, the more effort it takes to compress it and this effort acts as a damper/limiter to rising inertia loadings, so it’s actually safer to run with nitrous than without it.

24) MOST engine failures occur when the power is REMOVED, therefore if we just use a ‘simple’ law of physics that ‘APPEARS’ to state, that adding more power unavoidably results in more stress and therefore less power should create less stress, that should not be the case BUT IT IS A FACT.

25) It is also a FACT that THE REVERSE of what causes such failures, is responsible for why nitrous can make such HUGE power increases WITHOUT breaking anything due to increased ‘stress’.

26) The reason parts brake when you remove the power is as follows;
i) When the pistons move upwards they generate HUGE inertia loading, which as stated previously, rise exponentially as rpm rises and the ONLY THING that stops the piston crashing in to the head, is NOT the con rod BUT THE VOLUME OF CHARGE BEING COMPRESSED AND FIRED on top of the piston.
ii) If you rev your engine up to max and then throttle off instantly, the cushion of gases vanish (as does the start of the combustion process) and is replaced with a VACUUM and guess what happens to the con rod and big end bolts in the process.
iii) If you haven’t guessed it or don’t know, the answer is that THEY STRETCH and in so doing they weaken and will eventually break. So THE WORST THING YOU CAN DO to an engine is NOT to add more power but TO TAKE IT AWAY.
iv) As stated above, removing the gases that the engine is pumping leads to component failure, it therefore follows that INCREASING THEM WILL REDUCE COMPONENT FAILURE.

27) Conrods and conrod bolts are NOT as capable at handling stretching forces, as they are at handling compression forces, therefore the last points made above are EXTREMELY IMPORTANT.

Anyone who relies on the laws of physics and/or thinks such laws are ‘simple’ to apply and understand, should first make sure that the law itself is appropriate and being applied not only correctly but also with a full understanding of not only the law but also the subject it’s being applied to – THAT’S A BIG ASK for even the MOST QUALIFIED people let alone the simpletons on most forums who probably don’t even have an ‘A’ level in Physics.

There are no "simple" laws of physics and to think so will inhibit your understanding of many things in life. I'm always being told I'm wrong because of this law or that law but the FACT IS MY RESULTS PROVE I'M RIGHT!!!

More often than not, those that rely on those 'simple' laws of physics are either not applying them correctly or don't understand the full extent of the principles involved.

CLOSING STATEMENT;
Whilst adding nitrous from a badly designed nitrous kit (as ALL others are), in an incorrect manner and under certain conditions, will most certainly increase stress, just like most things, if the job is done correctly, the reverse can be the case and as I stated previously, IT IS POSSIBLE to run a nitrous engine which will deliver improved performance, WITHOUT increasing the risk of engine failure, when you KNOW WHAT YOU ARE DOING!!!

Hi

Wow that was a good read.....I am always amazed by the number of people who do not understand the basics of WELL DESIGNED Nitrous...


When people ask me..."what have you done to your engine and gearbox to take that extra Nitrous power"

My answer is....."NOTHING....ITS ONLY DONE 143,000 MILES so its hardly run in, and has a PROPERLY designed Won nitrous system"

And last time I looked, all 8 of my pistons were still there and not stressed lol

My engine is no different now to when I installed my first WON system around 4 years ago....no problems, no extra wear, nothing....

All the best Brett

I shall be making very good use of these facts Trev
3 weeks to go

I forgot to include a VERY IMPORTANT contributor to the load & stress lesson – DETONATION.

FACT 1;
Detonation is the result of any number of INCORRECT aspects of combustion.

FACT 2;
Detonation causes abnormally high combustion pressures

FACT 3;
Those abnormally high combustion pressures are generated in the form of extremely severe hammer blows, hence the term knocking as the hammer blows resound throughout the engine.

FACT 4;
The higher the induction temperature, the lower the level at which detonation will occur.

FACT 5;
Nitrous oxide injection super cools the induction charge, which raises the level at which detonation will occur or put another way, it reduces the risk of detonation setting in and killing your engine.
Since it is well known that detonation is the main killer of parts UNDER LOAD, and as it is not so much the pressures involved as the manner in which those pressures are generated (severe hammer blows) and as the CORRECT nitrous combustion process is a more sustained PUSH, they are at OPPOSITE EXTREMES and forces created by and the consequences of nitrous combustion can also be considered as the REVERSE of detonation.
I’m also going to generate some graphs and diagrams to help demonstrate as many of the FACTS listed above, for anyone who does not understand the printed word so well.

I was thinking that maybe I should keep my mouth shut. But I know that Trev is the kind of guy who likes all facts & opinions to be aired, so I'm putting my better judgment aside for the moment. If I might put my head on the chopping block...

I disagree with #18, at least in the world of the lower-revving V8 engines (i.e. up to 6000 RPM or so). Although on a given nitrous shot you certainly pick up more low-end torque than high-end torque, when you multiply the torque at that RPM by the torque multiplication from the gearbox, I have never found it advantageous to actually lower my shift points. The torque multiplication from the transmission is just too great to pick up speed by lowering shift points. And every time I've looked at torque curves vs. gear ratios, I've come to the same conclusion for every car I've ever looked at. (torque at wheels = torque at engine times overall gear reduction)

That might not be the case for motorcycles which have a completely different torque curve and RPM range, I have never looked at that closely enough. If you have enough gear ratios that are close enough (i.e. only a tiny RPM drop between gearshifts) then the principle makes sense.

However I'll add one more advantage to a nitrous motor - the ability to have a tighter torque converter for better drivability under other conditions (although how many automatic transmissions have a non-lockup converter anymore).

-BC

Hi Bob,

As you say (and contrary to what those who DON'T know me claim), I'm always HAPPY to have other people air their opinions and experiences, as long as it's done in a polite manner (as you always do) and having you ONLY disagree with that one, conversely validates the others.

I'm a bit short for time just now, so I'll get back with my response later tonight but I just wanted to make the above VERY IMPORTANT POINT in its own post, so that those who 'THINK';
1) my only purpose for my posts is self glorification
2) think I ban anyone who disagrees with me
3) talk out of my arse all the time

ARE PROVED WRONG.

I'M MORE THAN HAPPY TO HAVE PEOPLE MAKE POSTS THAT CONTRADICT MY OWN, AS LONG AS THEY (AS I), MAKE THE POST IN A POLITE MANNER, KEEP AN OPEN MIND ABOUT THE OUTCOME AND ACKNOWLEDGE THE CONCLUSION IF THEY ARE 'PROVEN' WRONG.

I would just like to state that in this matter, there may not be a right and a wrong, as is often the case with subjects with so much diversity, as there is in the automotive world.

ok you know I'm open to learn. but you also know I'm a small block ford nut! in my car it never see's over 7,200 rpm but that is at the end of the track I shift at 6,600 because the higher you shift the more stress is put on your motor. after saying that it is also know that n.o.s has alot of other factors. lets say you leave the line at 3000 rpm and leave at 100% n.o.s that would be very hard on your motor. however if you leave the line at the same rpm but only 30% n.o.s and increase it up to 100% it is less harmful. now saying that! all motors are not the same. some can take alot more rpm's then my motor but I'm going off mine. being it is a stock block 347 stroker. that see's a lot of n.o.s .
but there is a lot of factors to go fast. here are a few.
tire size
gears in the rear end
type and gear set of tranny
wieght of the car
the eng, I'll leave this one vage because there is a lot of factors in the motor. but lets just say every thing needs to match one another.

The following is a VERY ROUGH 'REPRESENTATION' of kinds of differences in combustion pressures involved that relate to my previous text.


http://www.noswizard.com/admin1/pdf/cyl ... sures1.pdf

all sound good to me

the shifting early thing makes sense, as in the longer in time the valves are open the more nitrous mix can be drawn in
and the fact that a nitrous mix is far more dense would give more power per time the valve is open, compaired to NA
the actual rpm range required would differ from engine to engine though? depending on the engine specific point of maximum efficency
if your engine was designed to make max power at 3000rpm compaired to an engine which makes max power at 6000rpm
the point at which you were shifting early would change considerably

also in ref to the removing of power breaking parts, i thought the exhaust stroke was the most stressful event in an engine?
no gas buffer, infact quite the opposite. the air is flowing out the exhaust valves creating a vacuum that the piston has to overcome as it passes tdc

so for maximum safety it's best to back off slowly, rather than snap the throttle shut
bonus of this is unloading the stress on the trans slower too =)

ABSOLUTELY CORRECT!!!

Here's the rest of the story above from the Wizard: