Jims5543

scathcart - Great write up!!



Good info. I want to run N2O on my car but after spending what I just spent on a rebuild / street port / 3mm apex seals I have become a little nervous about it. I just dropped a lot of money into my car and dont need to do it again any time soon.



I have a fogger systen sitting in my garage waiting for an install. I had planned on running an independant fuel system just for the NOS. AlL I want to run is a 50 shot but I really dont want to tax the existing fuel system anymore.



I am still baffled why Cam would say what he did about N2O damaging corner seals??



I talked at great lengths w/ Ari and he assured me that a well tuned 50 shot will get me much more than 50HP to the wheels on a turbo rotary application.



Thanks for taking the time to post up in here. Please stick around you would be an asset to this site.

Srce

Absolutly the best N2O write-up I've ever read. Thank YOU sir.

scathcart

No car comes from the factory with N20 because it has to be refilled. It is the same reason why Mazda did not make the owners premix, or fill a separate resevoir for 2 stroke oil to be fed by the MOP. The general public are idiots, who want performance without maintenance, such as bottle refills.



V8's dominate the dragstrip b/c they are big. Plain and simple. Displacement equals horsepower. It is not because they are any stronger, they are simply bigger.



There is no proof or theoretical evidence to say that the use of nitrous on a regular basis will destroy a rotary (or any other engine). I implore you to provide proof of this statement.





.... for a mechanic... you don't seem very knowledgable on the subject.

scathcart

There is no proof that a nitrous powered car will last any less. All conditions the same(identical torque curves, time under load, etc), the engine wear would be identical.



Fuel enrichment occurs under any WOT throttle condition. Under cruising and low load conditions, the engine attempts to run at a stoichiometirc value ~14.7 parts air to 1 part fuel for gasoline). Under WOT, this value decreases numerically in ALL engines (more fuel is added relative to airflow values), including naturally aspirated engines; this decreases the likelihood of preignition. Typically, an N/A will run down to 12 parts air to 1 part fuel at WOT; a forced induction car down to 11.0:1.



Due to the ideal gas law (PV=nRT), an increase in pressure will net an increase in temperatures. So, any form of compression will increase the temperature charge of the inducted air; this is the reason for intercooling; compression heats up the airflow. This is one of the main reasons for the lower AFR value of turbochargers.



Now.... nitrous oxide itself is not naturally volatile; it is an oxidant which only separates around 500 degrees. It conatins two nitrogen atoms which naturally act as a buffer to prevent detonation. Nitrous oxide actually enters the engine at an extremely low temperature value (-127 *F) due to the rapid change in pressure (again, ideal gas law). This extreme cooling, as well as nitrogen atoms, aid the nitrous oxide in actually PREVENTING detonation. Due to this, you can generally run a higher AFR when injecting nitrous than you can under boost, thus the engine uses LESS fuel, so you are completely wrong.



Really, though, why compare fuel consumtption under wide open throttle? Can you name me any vehicle which lists a "floored fuel economy value"?



Perhaps you were thinking that fuel is injected with nitrous under all rpm values, so therefore the fuel usage must be higher... except that you forget that a constant nitrous oxide amount is ALSO being injected. Thus, the horsepower is basically a full gain across the entire rpm band in which it is used. I would not complain about fuel usage when the gain is a conastant across the band.



And with nitrous... you can keep the fuel economy down simply by... not engaging the nitrous system.



There are no current nitrous oxide systems that use their own fuel injectors. There are two types of nitrous systems: wet and dry. Generally, dry systems run an FMU and merely up the fuel pressure whenever the system is engaged. More fuel pressure= more fuel into the engine... not exactly what I would call precise, and it also lowers fuel pump output (due to the higher operating pressure of the system). A wet system physcially installs a set of foggers, which inject the nitrous in a dense mist mixed the the nitrous oxide.



Your BMW example is moot: its a factory designed BMW. BMW's are far superior to Mazda's in build quality; this is well reflected in the MSRP's. As well, no stock car comes with nitrous oxide; you can compare a stock car to a modified one when it comes to reliability. To cliche: compare apples to apples. You can't compare a tiger to an elephant... there's no such thing as a tigerphant.



Your example of a "12-guage shotgun" is also moot. It is the power of the combustion that prodcues power. So let's say you have a 200 hp engine. You strap on a 50 hp nitrous kit and make 250 hp. Then you strap on a turbocharger and make 250 hp. The combustions will be nearly IDENTICAL, as they produce the same power. Therefore, the addition of 50 hp with a turbocharger (or free-flowing exhaust, whatever) is ALSO equivalent to your shotgun example.





Please stick to documented facts, not misconstrued takes on what you think may occur.

scathcart

Completely incorrect. Combustion chamber temperatures are only slightly increased over turbocharger combustion temperatures (less fuel required). As well, the cooling system should keep the coolant rings at a relative constant temperature, that is its job.

scathcart

Improper installation of the fogger nozzles *might* cause thermonuclear shock to the corner seals, cracking them. I have never seen it happen.

There is no reason for them to break. Perhaps you could ask him for his logic?



Ari is right. For one, an advertised jetting horsepower will generally net you that power amount, or slightly higher, to the wheels. This equates to more power at the flywheel. As well, the extra exhaust gases produced from the combustion of nitrous oxide greatly help with the spool of the turbocharger. Lastly, the cooling effect of nitrous oxide will virtually eliminate the heated air charge of the turbocharger, and thus make the gain from the utrbocharger even higher.

89Turbo944

The engine wear would not be identical. The initaial combustion ofnitrous oxide is a sudden impact on the engine. Not a smooth(well relitivly) application of boost. This will cause premature wear. There is no way around it.





When did i compair a vehicle under WOT? I never even mentioned at wide open throttle.







The BMW was made in the 70's. It was a very poor design of a car. ANd it sold for far less than the RX7. It isvery far behind in the technoligical standpoint. And no its not far superior in build quality. Its quite poor as BMW's go.





NEVER did i say that adding powere was equivilant to a shot gun shell. I said that the instintanious addition of 50hp or more to an engines confined combustion chamber is equivilant to a 12guage shot gun shell exploding. The turbo may make the same force but it is applyed over a gradual period of time not all at once.

This stress is what kills the engine.





LOL. My misconstructed facts make me $85,000 a year. If thats wrong then im fine with being wrong. I work on cars all day long. If you would like to disagree with me go right ahead. Its your right to have your own opinion. But i know for a fact that a car running n2o will not last like a factory turbocharged car will.

scathcart

Initial combustion is not a factor unless the shock goes above the 500 hp range on a stock block. Prove otherwise, I have.

How does the size of the combustion have an effect on wear? If the engine misfires on one revoltion, then fires on the next, is their increased wear (100% increase of power over the last revolution)? Nope, so why sudden addition of nitrous increase wear?

Nitrous very rarely causes the engine to let go the moment it is engaged; it typically comes higher in the torque band when the engine internals are overloaded with more torque than they can handle; a connecting rod will snap, the mains will drop, or cumbustion chamber temps will melt a piston. If the "initial shock value" is so high, why do the engines not let go the moment it is engaged (nitrous backfire aside)?

Sorry, you are just stating what you think may occur, which is not correct. I have done testing on this matter on rotary engines. I have built engines ran hundreds of pounds of nitrous through them, and then dissassembled them to measure the changes in wear. You have not. Until then, it is upon YOUR shoulders to prove yourself. Until then, your statements are invalid.



You compared the fuel injection values of nitrous oxide against a turbo, saying that since fuel injection values were constant, and thus use more fuel. Without the aid of a nitrous controlelr, which 99% of all users do not have, nitrous oxide is only ever engaged at WOT, unless the system was incorrectly installed. So, yes, you were comparing WOT fuel consumption, which is not only pointless, but you were wrong in the matter since turbo cars run a lower AFR anyway.



Again, you cannot compare a factory turbo car to a nitrous car; it is a stock engneered car compared to a generically engineered aftermarket part installation. You cannot compare the reliability of a 700 hp PP to a stock 146 hp N/A, no one would even try to.

If you want to make a comparison of turbocharging to nitrous oxide, perhaps you should look at the honda scene; a car well known for its reliability. Plenty of honda owners are running 55-75 horsepower shots with great success and zero reliability problems. Upon slapping a turbocharger which adds approximately the same power vlaues, reliability takes a dump. THAT is a fair comparison, as both parts are aftermarket.

Comparing an aftermakrte car to your dad's BMW is tiresome and pointless.



I am glad that you are making $85,000 a year. Perhaps that will buy you some tact? Regardless, your annual salary has nothing to do with whether or not you are right. If you made a million annually, you'd still be wrong.

(as a side note, I am a mechanical engineer, so you're not really impressing me with your salary, and you will surely lose in any attempt to argue physics with me).





Now, in your next post, please don't respew your misconstrued facts, I am not here to argue against repetition. The weight is upon your shoulders to provide proof, either via correct physical explanation or via experimentation. Until you can provide such, please withhold your opinion on this subject. I am interested in facts.

9BASE3

Wow. This is a first!! A CONSTRUCTIVE argument!!

89Turbo944

Well so far im tired of arguing, and you made a very good point.



I dont have the patiance to find information backing my facts, so i will step down.



scathcart you need to poste in some other areas of this forum. Like second gen specific. You know your stuff.



O and yes i was basing my information off of personal experance, im basing it on the fact that i have seen many a car blow the hell up running n2o. Not on actual facts. So i will take your word for it.



PS dont use so many big words, wes all simple folk.