NA Vs. Turbo

[tmnothing]

I apologize in advance if this has been explained before, but I have been searching around on the net and in this forum and I have not found a clear set of answers to my questions.

What I want to know is the difference between NA and Turbo cars? (What does NA stand for anyway?) Why do some cars all you to purchase the NA Tuning upgrades and the Turbo upgrades, but then some will only let you purchase one or the other? And the cars that do let you purchase both types of upgrades, why does purchasing them both seem to cancel HP gained by the other? Can somebody please clear all of this up for me? Thank you in advance.

 

[Scaff]

I apologize in advance if this has been explained before, but I have been searching around on the net and in this forum and I have not found a clear set of answers to my questions.

What I want to know is the difference between NA and Turbo cars? (What does NA stand for anyway?) Why do some cars all you to purchase the NA Tuning upgrades and the Turbo upgrades, but then some will only let you purchase one or the other? And the cars that do let you purchase both types of upgrades, why does purchasing them both seem to cancel HP gained by the other? Can somebody please clear all of this up for me? Thank you in advance.

NA = Normally Aspirated

NA can be most easily understood as recieveing no assistance in the supply of air to the engine. A turbo charged engine uses waste exhaust gas to drive a turbine that forces more air into the engine, which allows more fuel to be burnt and produces more power.

These are very basic descriptions of the two, for more info read the following

http://www.howstuffworks.com/engine.htm

http://auto.howstuffworks.com/turbo.htm

The ability in GT4 to purchase different upgrades is very roughly based on what you can do to the car in reality (but I do mean very roughly). As far as only being able to do one at a time, that's GT4 attempt to show the difference in upgrades between the two. So you can go down a NA or Turbo route to more power.

The above really is very basic, and the web and here at GTP do contain a huge amount of info on both.

I'm also moving this to the tuning and settings thread, as its a lot more relevant to that area.

Regards

Scaff

 

[Kent]

Not sure about this but I believe "NA" could be "naturally aspired" as well as "normally aspired."

I believe the two are inter-changeable and after checking the wiki it seems that is confirmed.
http://en.wikipedia.org/wiki/Naturally_aspirated

 

[eg6_dude]

I have also heard of people referring to it as Mechanical Tuning before.

 

[tsukuba_drifta]

hi
I was just reading and "NA" stands for (naturally aspired)

but me i would stick with the turbo but thats just me.....

 

[tmnothing]

Great, thanks for the explanation I think that I have it straightened out. So am I correct in thinking that you want to use either NA Tuning to increase HP or Turbo to increase HP, but not both?

 

[Scaff]

hi
I was just reading and "NA" stands for (naturally aspired)

Sorry but its Aspirated, not Aspired.

Aspired from the word Aspire, meaning to long, aim, or seek ambitiously; be eagerly desirous, esp. for something great or of high value.

Aspirated is from Aspirate, meaning to draw (something) into the lungs; inhale.

One has to do with desiring things the other to do with the follow of air or liquids, a naturally aspirated engine is drawing air into the engine without any forced means. So its aspirated rather aspired.

What does add confusion is that the word aspiration can be used for both of these meanings, but in the case of an engine its naturally or normally aspirated.

A naturally-aspirated engine or normally-aspirated engine (or "NA" - aspiration meaning breathing) refers to an internal combustion engine (normally petrol or diesel powered) that is neither turbocharged nor supercharged. Most automobile gasoline (petrol) engines are naturally-aspirated, though turbochargers and superchargers have enjoyed periods of success, particularly in the late 1980s and the current 2000s era. However, most road-going diesel-engined vehicles use turbochargers, because naturally-aspirated diesels generally cannot offer suitable power:weight ratios to be acceptable in the modern car market.

Air or fuel-air mixture is forced into the cylinders by natural atmospheric pressure upon opening of the inlet valve or valves. The pressure within the cylinder is lowered by the action of the piston moving away from the valves (so as to expand the volume available for incoming air). In some cases the lowering of the cylinder pressure is enhanced by a combination of the speed of the exhaust gases leaving the cylinder and the closing of the exhaust valve at the appropriate time. A tuned exhaust can help with this but generally only works at a narrow range of engine speeds and hence is most useful in very high performance cars, aircraft and helicopters. Many NA engines today make use of Variable Length Intake Manifolds to harness Helmholtz resonance, which has a mild forced induction effect but is not be considered true forced induction. Cylinder head porting design is of premium importance in naturally aspirated engines. Camshafts usually will be more "aggressive", having greater lift and duration. Also, cylinder head gaskets will be thinner, and with the top of the piston rising up into the combustion chamber, for high-performance NA engines that benefit from higher compression.

Naturally-aspirated engines generally gives less power than either turbo or supercharged engines of the same engine displacement and development level but tend to be cheaper to produce and more fuel-efficient. In drag racing, naturally-aspirated vehicles are vehicles that do not run a blower, a turbo, nor use nitrous oxide.

Many racing series specify NA engines to limit power and speed. NASCAR, Indycar, and Formula One are all in this category. Naturally-aspirated engines have been mandated in Formula One since 1989, in order to curb the excessive powers being developed by engines with superchargers or turbochargers.

Source - http://en.wikipedia.org/wiki/Naturally_aspirated

Great, thanks for the explanation I think that I have it straightened out. So am I correct in thinking that you want to use either NA Tuning to increase HP or Turbo to increase HP, but not both?

Glad we could all be of assistance and yes yo are right that you can only take one tuning route at a time.

Regards

Scaff

 

[project.s13]

hi, NA is naturaly aspirated and its basically modifying the cars engine to its optimum level without using a turbo. with a turbo you get more power but you have to wait for the power to build up, (this is turbo lag) whereas in an NA tuned car as soon as you accelerate the power is there straight away. i prefer using NA cars as they have more power out of tight bends

 

[eg6_dude]

... i prefer using NA cars as they have more power out of tight bends...

That is a very general statement and not one that is always true.

First of all the throttle response and power control is the major upside over Forced induction, bucause your foot (or button in this case) decides when to apply all the power avalible at that RPM, rather then forced induction where your foot applies some power and in-turn signals your turbo or supercharger (or twin charger) to apply the rest of the power avalible at that RPM when it can. So turbo lag would then be referred to more as a power delay, because the power is there and you just have to wait for it.

Second, just cause a car is NA and a car is Turbocharged doesn't auotmatically make one faster out of a corner then another. There are many varibles that should go against that statement. The overall power of both cars, the drivetrain layout, useable powerbands on each car, weight, the layout of the corner, track conditions, tourque, wheel and tire size, etc.
If you were just to approach this using the same exact car with two different engines and similar HP there would still be varibles. The engine size, because larger displacement engines with turbochargers (size pending) tend to have less lag, because the generate more exhaust gas to spool the turbo faster. The engine tuning (cams, compression ratio, stroke, valving) would also have to be taken into consideration. Special varible valve timing systems like VTEC, VVT-i, MIVEC, etc. would also play a part.

For a quick example to prove your statement not always correct we will use a Civic Type R (EP) and a new Golf GTi. Coming out of a tight corner the golf would have a significant advantage. The reason being is that the golf uses a small turbocharger to not only gain power, but a considerable amount of torque also was gained. Giving the Golf far more tourque then its opponent and almost the same throttle response as well. So to finish the senario if the both applied power at the same time the Golf would lunge ahead, while the Civic waits for i-VTEC to kick in and then they would be going at basically a even speed with the Golf out front. If the corner was a little faster then the Civic would be able to use its limited powerband better and would be able to keep even the whole time.(this is all theoretically) So you see that NA are not always faster out of corners. In fact I would have to say it is about 50/50depending on car specs, surface, drivtrains, etc.

I hope you understand what I am trying to say!
Didn;t mean any offense, just trying to teach you something new! 👍

 

[Alfaholic]

OK How about this for a difference, and also an explanation of why turbocharging and N/A tuning cannot be applied simultaneously?

First, and most obvious, since N/A means natural aspiration, it therefore means unassisted breathing. Since turbos and superchargers assist breathing, they are as different to NA tuning as petrol is to diesel. Two different methods of achieving the same thing.

What they both do is make an engine process more mixture and therefore produce a bigger collection of bangs per minute. To make a normally aspirated engine process more mixture you widen the ports and / or increase the valve lift and duration and / or increase maximum engine speed. All of these tend to produce more power at high revs but less at low revs. So you can make the bangs slightly bigger but you spend more energy in getting more bangs per minute. A turbo gets more mixture into a cylinder by forcing it in under pressure, and so effectively increases power by increasing torque. In other words, turbos simply make each bang bigger. This tends to give turbo charged engines a wider powerband and a more muscular feel, whereas an NA tuning will tend to feel more, um, athletic. Turbos do suffer from lag and a spongy throttle response because of their drive system. Superchargers work like turbos - in fact a turbocharger is simply a supercharger with a gas turbine, allowing it to be driven by the exhaust. Superchargers don't have to suffer the lag or spongy response of a turbo, but their drive system tends to be less energy efficient so they don't provide such a big net power gain.

You could in theory apply N/A based breathing and revving principles to a turbo installation for even more power, but a turbocharger, like any pump, has a maximum capacity and can't supply enough volume of air at high revs unless the turbo is really large. Large turbos give more lag and too much air at low revs and... it's all a compromise.

In reality turbocharging is usually the cheapest and most effective way to make significant power gains. N/A tuning to high power levels uses a lot of very expensive processes and also can have bigger compromises. Toyota's VVT-i engines are a good example of how tuning for high revs compromises low engine speed driveability. Even V-TEC engines aren't that pleasant at low revs.

 

[MusclecarChhris]

so, turbo would propably get more power, if you had the op to use it. superchargers are better for races that need more aceleration than top speed, and naturally aspirated is best for long endurance races where you dont need the exess pitting for fuel, as na saves gas. am i correct?

 

[Ev0 4 drifter]

N/A doesn't save gas because turbos use exhaust gases, at least i think thats right, also, if you had a twin turbo car with one small turbo and one big one, would you have a more constant power band because the small one works at lower RPM and the big one kicks in at higher RPM?

 

[articzap]

You also have to be in the right gear when you exit the corner. If you do this on a turbo'd car, you'll almost always be in the power band.

 

[eg6_dude]

so, turbo would propably get more power, if you had the op to use it. superchargers are better for races that need more aceleration than top speed, and naturally aspirated is best for long endurance races where you dont need the exess pitting for fuel, as na saves gas. am i correct?

There are many varibles to figure all that out. Turbo cars don't always have more power then NA. It depends how extreme you go in each situation. There is also more then one kind of supercharger. For example, an eaton roots type supercharger will generate more torque low down in the power band (when people think of superchargers this is the type they generally think of), and then there is the centrifugel type (not sure if I spelled that right) that makes more power at the mid range to high end of the power band and power output feels similar to a turbocharger, just without the lag. Both of these methods are inefficient compared to turbos, because the exhaust gas drives turbos and superchargers run a belt from the supercharger to the crankshaft pulley and use that to spool the up. As far as gas saving I have seen turbo cars that use a lot of gas and NA cars that use a lot of gas, and turbo cars that use little gas and NA cars that use little gas. That subject depends on alot of varibles.

... also, if you had a twin turbo car with one small turbo and one big one, would you have a more constant power band because the small one works at lower RPM and the big one kicks in at higher RPM?...

Alot of twin-turbo cars use this system and the idea was for it to work exactly how you described it. The Supra, RX-7, Skyline, and the 300ZX all used that kind of system. I believe it was called sequential turbocharging. 👍

 

[sucahyo]

You could in theory apply N/A based breathing and revving principles to a turbo installation for even more power, but a turbocharger, like any pump, has a maximum capacity and can't supply enough volume of air at high revs unless the turbo is really large.

Many turbo (not just really big) could produce more pressure than what engine can handle (safely) too. Many turbo instalation provide blow off valve to release excessive pressure at high rev.

Toyota's VVT-i engines are a good example of how tuning for high revs compromises low engine speed driveability. Even V-TEC engines aren't that pleasant at low revs.

Actually, VVT-i or VTEC work to get better power at high engine speed without sacrifying much power at low engine speed, to distribute engine power more evenly on low and high engine speed. They have different name on different manufacturer: Toyota VVTL-i, Porsche Variocam Plus, Honda i-VTEC, Audi Valvelift, Rover's VVC, Nissan VVL, etc. And I've seen it help 600hp turbo car get better low rpm acceleration too (some BMI video about HKS variable valve or something on Skyline R34).

You can read better explanation on AutoZine Technical School


IMO, to see which one better, I will take the car to 1000M test and see which one fastest. Since it would be hard for me to guess which is better only from hp. Turbo could give better tourqe and NA could give better engine response.

 

[michael15]

i like mid range torque. I just love the Viper GTS with it's 1100nm @ 3000rpm. it goes like hell when floured in 3th @ 3000rpm. While a skyline with the same power only has 900nm and accelerates slow at low rpm's.
I like the high reving cars like the S2000 or SSAE86 but it needs short gears. V8's usely suck but the super tuned cars are great.
I prefer NA.

 

[Jak 22B]

well explained scaff 👍

 

[mt00]

i have noticed sometimes on turbocharged cars when you are at you top speed the speed gets to the top then drops about 15mph then works its way up again

 

[fast fun 2]

Not sure about this but I believe "NA" could be "naturally aspired" as well as "normally aspired."

It is

 

[Escalade_dude]

Turbo. It is way better than NA! The HP goes up the most. In this emoticon, the yellow guy is NA and the red guy is Turbo.

The red one won. Same in a race. 'The Supercharger' is the best! In "Tuner Village", you can get even more Turbo Engines (Not every car is excepted). The NA Engine gets too cold.

Turbo is the best all the time! The car always runs smoothly.

By the way,

! I wanted to tell all the crazy people that like NA, that Turbo is way better! Go Turbo!

 

[GT_Jim]

Turbo is better only in GT4, in real life it has many disadvantages.The only advantage is the horsepower. In GT4 of course is more useful.

 

[Scaff]

Not sure about this but I believe "NA" could be "naturally aspired" as well as "normally aspired."

It is

If you are referring to the use of 'naturally' and 'normally', then yes either can be used. That doesn't however make 'aspired' correct, its aspirated, take a look at post 7.

Turbo. It is way better than NA! The HP goes up the most. In this emoticon, the yellow guy is NA and the red guy is Turbo.

The red one won. Same in a race. 'The Supercharger' is the best! In "Tuner Village", you can get even more Turbo Engines (Not every car is excepted). The NA Engine gets too cold.

Turbo is the best all the time! The car always runs smoothly.

By the way,

! I wanted to tell all the crazy people that like NA, that Turbo is way better! Go Turbo!

Quite some rant, but I would have to firmly place myself in the crazy people camp, NA is the right option some of the time and turbo certainly does not always win.

NA tuning may generally give you a lower total power output, but it does tend to increase power across a wider range of revs, helping in certain situations to make that power more accessible. Turbo's and 'chargers tend to limit the power to the upper or lower rev ranges, potentially making it more difficult to exploit. Traction can start to become a major issue at times as well.

One is not automatically better than the other, they all have a place. For example a nice wide open track, with long flowing sweepers will certainly favour a turbo, but a short track with tight slow hairpins and no major straights will favour a NA.

BTW - Could you watch the use of 'smilies' in future, no one minds them as an addition to a post, but when they start to take over the post its more than a bit distracting.


Regards

Scaff

 

[GT_Jim]

It's just a matter of age; For you or older people who are drivers in real life, NA is far better, and you are right to believe that. "Kids" younger that 17 haven't driven in real life and like turbo because of the blow-off valve noise and because of the many hp when they see a video with 1000hp Skyline. "Turbo-lag" is just a word for them. I am a "kid", too, but I know the advantages/disadvantages of turbo/NA, that's why I said that.

 

[Escalade_dude]

BTW - Could you watch the use of 'smilies' in future, no one minds them as an addition to a post, but when they start to take over the post its more than a bit distracting.


Regards

Scaff

What is wrong with smilies? Sometimes they explain things better. For example, in my case.

It is not destracting! The post looks kind of boring without smilies.

Bye Scaff! (or fast fun 2)

 

[Car-less]

The occasional smilie is fine - as you say they can help explain things better.
However, a post filled with smilies like the ones above are distracting. It's almost a step backwards to writing in hieroglyphics!

It also doesn't help when not all the smilies load. Both smilie laden posts 20 and 24 in this thread contain a broken pic, or a little red x. Hardly clearer than expressing yourself in text.

 

[Scaff]

What is wrong with smilies? Sometimes they explain things better. For example, in my case.

It is not destracting! The post looks kind of boring without smilies.

Bye Scaff! (or fast fun 2)

I don't believe I said that anything was wrong with smilies themselves (in fact I did say "no one minds them as an addition to a post"), rather it the overdose of them that many find distracting.

I'd personally have to disagree that this one...

..helps to explain why you believe that Turbo' are always better than NA. At most it shows that should you need to get a red cross out of the air then a gun is better than a stick, how that relates to turbo vs. NA I just don't see.

As I said before, smilies in themselves are not a problem, but making the core of you post a reason to use smilies is both distracting and to be honest you do run the risk of some members not bothering to read it or simply not taking it seriously.

Now lets get back on topic.....


Ta

Scaff

 

[eg6_dude]

It's just a matter of age; For you or older people who are drivers in real life, NA is far better, and you are right to believe that. "Kids" younger that 17 haven't driven in real life and like turbo because of the blow-off valve noise and because of the many hp when they see a video with 1000hp Skyline. "Turbo-lag" is just a word for them. I am a "kid", too, but I know the advantages/disadvantages of turbo/NA, that's why I said that.

I am a kid and I love NA and turbocharged engines/cars. Both are great and both have their disadvantages/advantages so I believe your theory may be incorrect.

 

[GT_Jim]

I am a kid and I love NA and turbocharged engines/cars. Both are great and both have their disadvantages/advantages so I believe your theory may be incorrect.

I believe the same
Well, I just believe that's true sometimes. Anyway

 

[mt00]

In "Tuner Village", you can get even more Turbo Engines (Not every car is excepted)

what is tuner village. it is something you unlock when you complete the game?

 

[Niels]

It's spelled as Tuning Cars on your main Gran Turismo 4 menu. It's also refered to as the Tuner Village.

I am a kid and I love NA and turbocharged engines/cars. Both are great and both have their disadvantages/advantages so I believe your theory may be incorrect.

But you've proven that you have done some research, before choosing a side and defend it. To be honest Escalade dude, to me kind of resembles a person who chooses a side without not really knowing some stuff about the subject.
That could just be, because of his unecesarry smilies though (I'm not a fan of those type of smilies).

And that's proof that I'm one of the persons Scaff talked about. That's when he said people might not take someone seriously with an opinion that's only supported by some random smilie.