Neo

[iliketocrash]

Has anyone read much info on nissan's new NEO "modification" i guess you could call it. Some of the RB series engines are now NEO-ized. I guess it stands for Nissan Ecology Oriented or some crap like that. It says it enables the engines to run considerably cleaner and also produce more power throughout the entire rpm range by use of some sort of variable intake manifold, variable valve timing and other such tricks. It sounds good and all, being that it greatly lowers emissions and seems to boost power, but i'm wondering if tuneability is lost... I have the opertunity to buy a NEO RB series engine but i don't know if it'll be worth it. Opions, info, suggestions, anyone?

BTW - I'm not completely sure if this thread belongs here or not but i'm sorry if it doesn't.

[Q45tech]

The length and the diameter from the point of valve opening to the plenum.........tunes the point [time in degrees when the 1st,2nd, 3rd ,4th harmonic] reinforces the air pressure via a reflected wave. This reflected wave give a final push to the air flow just before the intake valve closes.On passenger engines this push can increase filling by 10%. Thus the engine produces 10% more torque than one would expect from a non tuned average engine........unfortunately the finer tuned the sharper the peak.

On a 90Q the tuning points are fixed except for slight variations due to air temperature in the runners. The whole system has minipeaks at 1500 rpm, 2000,rpm, 3500, 3700, 4000, 4600, 5500 and 6,000 rpm......3,500-6,000 are the result of the runner diameter and length 1st, 2nd, 3rd,& 4th harmonics.....1500 and 2,000 are the result of the length from air horn to plenum and the tuned cavities in front of firewall.

The 1st and 2nd harmonics are stronger and decline in amplitude as you go to higher orders..........most varible tuning plenum/runner lengths tune the 2nd harmonic.

Many engines have a two volume plenum and 2 length runners via a flip valve........14 years ago the 400 HP ZR Corvette engine had different runners for each valve. And a low flow and a high flow injector for each cylinder.

Continuously variable length or/and diameters are an engineering nightmare for the 10% gained across the board.

Note that many have just bumped the displacement [costs less except in fuel usage] than these complicated systems.Europe and Japan tax car based on displacement so efficiency is the name of the game whereas in US we tax fuel mileage and allow manufactuers to stretch the truth so we end up with larger less efficient domestic engines.

[iliketocrash]

But would it be worth to buy one of those engines? Would it still be easy to mod the engine or would these systems make it more difficult or just not allow it?

[Q45tech]

Modify how? they are already on the edge.If you mean changing cams that would really upset the tuning.

ODB2 engines are very difficult to modify unless you just slap on a radial supercharger.

[forecast]

quick note on the tax. I owned a car in Italy. The annual tax was based on horsepower (counted by Kilowatts) it works out to something like $3.50 per horsepower every year the car is on the road. Italians would always tisk tisk at my 78 Hp Volkswagen Polo (think a Passat cut down to 5/8 size). Who needs that big of an engine?

The $4 gallon gas is really what drove effieceny. The car did get upwards of 40 MPG

[Q45tech]

Efficiency is a function of displacement [bore size-ring diameter] and the air flow 2 vs 4 valves primarily.

A HP requires x amount of air flow into cylinder to create.....roughly 1.2 cfm per and 0.5 pounds of gasoline per hour..........many engines produce a lot of power only to throw it away in internal friction........to cut manufacturing cost or to increase durabilty........thick iron blocks, big bearings, heavy conn rods, etc.

[iliketocrash]

Efficiency is a function of displacement [bore size-ring diameter] and the air flow 2 vs 4 valves primarily.

A HP requires x amount of air flow into cylinder to create.....roughly 1.2 cfm per and 0.5 pounds of gasoline per hour..........many engines produce a lot of power only to throw it away in internal friction........to cut manufacturing cost or to increase durabilty........thick iron blocks, big bearings, heavy conn rods, etc.

So you're saying lighter and better manufactured internals would help efficiency? Does an iron block make that much of a difference in efficiency or is there a way the cylinders could be machined/prepped differently to help counter the negative effects? or does it have more to do w/ the iron block retaining more heat? or am i just stabbing blindly in the dark?

[maxnix]

[Que the music to the psycho shower scene here and turn-off the lights.]

[Eswift]

to answer your initial question, its not worth buying. There is no support for the RB series over here, unless you have plenty of money to throw away.

to you, NEO means that the engine is even harder to modify for performance.

also keep in mind that some many (especially domestic) aluminum blocks have integrally cast aluminum sleeves or piston liners, so it isnt quite that simple.

cast iron wastes energy mostly through frictional losses, as dennis said. dont feel like getting into tribology now.

[s13sr20chris]

well i certainly appreciate you guys breaking it down for me. i am a college dropout/nissan dealer tech and i would like to go back to school for mech engineering in the near future(a long way from my original major-chemistry). in the meantime, keep the good tech stuff coming as well as the excellent links. those links seem to be far more credible than the "how to hook up your civic".com's i have been running into for so long.

[Q45tech]

If you think about it Nissan has changed from building thick and heavy to light and weak [but weak is relative as long as you don't exceed the designed power levels] ....because of the safety factors.

Unfortunately it will take 7-8 more years [or secret info from Nissan destructive testing] before we can see enough miles on engines to reverse calculate the effects of what is a safe power boost and how it effects durability.

The SR20 is a great example of whats is possible as is the 300zx tt motor or the Q motor going 250,000-300,000 miles.

Formulae for rod stress are well known.

[Eswift]

hey no problem at all. if you ever want to get more info than on this board, there is a periodical, racecar engineering, available at borders, which puts some really cool ideas and all the theory in non-engineering terms. no formuae, but when something technical arises, it throws in graphs, charts and cutaways to aide in explanation.

in any case, good luck with the degree, if you decide to pursue. I am working on my ME right now, and to me, what im learning is the coolest stuff imaginable.

[M635CSL]

Eswift, I've always been interested in the how aspect of cars. and lately I've gotten more intersted in the why. Currently I am halfway through my enlistment in the U.S. Marine Corps, and I am looking into college options for when I'm out. I have begun researching a Mechanical Engineering Degree, but all of the catalogs that I have looked at only mention the automotive aspect in passing, and focus more on aerospace. What kind of career opportunities are there in the automotive industry for someone with a Mechanical Engineering Degree?Thank you for your time,-Eric

[Eswift]

opportunities for an ME? anything! just specialize. If you want to work with cars, youll want to start out with mechanical engineering.

Every automotive company I have ever looked at has opportunities for those with a BS in mechanical engineering.

There are specific automotive engineering or automotive engineering technology degrees and majors at some schools, but i dont know if they are accredited, and many are found soley in 2 year colleges.

i have several friends that graduated (from UIUC, here) just this May with a BS in ME and are working for places like Ford, nissan, etc.

It takes quite a while before you can get into the automotive specific stuff, but if you are interested enough, you can put toether what is in your textbooks with what you already know about cars, and teach and learn stuff for yourself. this is what i have done for the last 3 years. in fact, i have yet to take an automotive-specific class. yet, all the classes i have taken relate in some way to automotive design, whether it be dynamics, fluids, thermodynamics, CAD design, materials, you name it, its all really important for cars. now i have 2 semesters to jam with all the car crap i can fit.

Many schools also offer a astro/aeronautical engineering degree, so it isnt always smushed in with ME, (although they are essentially identical classes until the last 3 semesters)

there are a couple of MEs here that (i believe) did what you are looking into, going from enlistment and then to school, i think one of the guys plans on opening his own motorcycle shop.

in any case, the possibilities are endless.

[7thGear]

what sort of courses did you take for ME?

I got a 60 in physics OAC back in highschool and never even touched chem or algeo, currently working on a business managment/accounting degree, but my heart lies with cars.

[Eswift]

prerequisites:: calc I and II, all chemisty, as well as other basic requirements.

first, basic classes are taken:: calc III, mechanical physics, electromagnetic physics, thermophysics, quantum physics (why? i dont know) and some CAD.

this is what i would consider the step up:: thermodynamics, statics, dynamics, mechanics of materials, materials science

another step up:: analysis of dynamic systems, control systems, differential equations, linear algebra, design for manufacturability, fluid dynamics, machine design I

another step:: (still havent finished all these): heat transfer, machine design II, fracture mechanics, energy conversion systems

for the future (now its time for some car stuff):: automotive vehicle dynamics, internal combustion engine, internal combustion engine design, refrigeration systems, automotive systems, tribology, diesels tractors and power movers....etc

I am pretty sure most ME BS degrees progress in the same manner, with small differences here and there...

if an ME degree isnt for you, there are great alternatives offered at community colleges everywhere, which are definitley superior on a "hands-on" perspective. I would kill to take a class where you rebuild engines or learn to weld (better), but its just not offered here.... in fact, i plan to do some stuff like that over the next few summers.

Unless you want to be an engineer, going into ME isnt worth it. I wanted to be an engineer and i like cars, so it works out. But if i didnt have to, i definitley wouldnt take all these ridiculous courses: hands-on stuff would definitley be better for the average car enthousiast.

[Def]

Getting an ME degree is knowing the "why," if you want to do things hands-on, then you want to go to a trade school and learn the "how."

BTW, I'm about where you are in my BSME Eswift - still not really sure I know what I want to do. I "think" I want to do something with cars, but I don't want to ruin my love for the hobby. I'm pretty sure I don't want to work for a big auto manufacturer, so I'll just have to see what comes up. Hate the uncertainty though, and the job market SUCKS now.

BTW - unless you are at least "good" at math - don't bother with an ME degree. I never had ANY problem with math, it was just easy to me - but at times I want to pull my hair out on some classes. They're just like, "Ok, now this is a set of coupled, non-linear differential equations. I won't bore you with an example, so let's move onto the next topic!"

Although at times I think it's just poetic justice that I'm at a "good" school and getting beat over the head with maths like that.