Talk:Turbocharger/Archive 1

Simplify?

Does anyone else think this article is very bloated with useless facts? We don't need a doctorate thesis on every turbocharged engine that has ever been built, so I say we start cutting the crap out. Unfortunately, I know a lot of people who contributed that crap are going to be upset. Anyone with me? Shreditor 04:22, 10 May 2007 (UTC)

Yes, you are right, the article is too long, with alot of unnecessary facts, it needs to be shorten. 89.148.45.199 15:50, 16 August 2007 (UTC)

Reats?

Can someone besides me start deleting the pointless, meaningless statement "turbochargers are reats" every day?

I requested for the page to be protected but some admin refused as per below. --Baldur 22:05, 8 December 2006 (UTC)

Turbocharger (edit | talk | history | protect | delete | links | watch | logs | views)

semi-protect. Constant IP vandalism. Baldur 10:48, 8 December 2006 (UTC)

There is not enough recent activity to justify protection at this time. Just watchlist and revert any vandalism. Nishkid64 15:01, 8 December 2006 (UTC)

Hi, I agree with Nishkid's decision not to protect, but have watchlisted it and will block vandals and/or semi-protect as appropriate. | Mr. Darcy talk 22:23, 8 December 2006 (UTC)

I reverted some serious vandalism to a more appropriate version. I know I now messed up the history but atleast the article is good again. I also request a semi protection for this article due to repeated vandalism. Kind regards, MisteryX 08:51, 3 May 2007 (UTC)

Blow-Off Valves?

I think that someone should perhaps add a section on blow-off valves, what they do, how they work with the turbocharging system.. etc

Dump valve and Blow off valve don't serve? This article is plenty long enough already. --Baldur 22:07, 8 December 2006 (UTC)

---

Constant Speed Turbocharging ?

Is it a revolution in Turbocharging (see http://abgasturbomaschine-extrem.de) ? Look the german discussion page.At the petrol engines you can use the compressor wheel as turbine wheel in the part load range, if you place variable guide vanes above the shroud of the compressor wheel entry. This variable guide vanes replaced the throttle valve of the petrol engines.

---

TURBOBRAKE

The first truck engine brake which operate with active turbocharging in the braking mode (look the german discussion page).

---

Please people, stop adding information that isn't factual. The Porsche 911 was not the first gasoline car with a VNT turbo!

I'd like to make a suggestion that should be added to the turbocharger and supercharger articals.

The most efficient use of fuel is going to be achieved when the length of the power stroke is long enough to take 100% of the power from the working fluid. At this point the pressure in the expansion chamber will be at atmospheric pressure. If the engine does this then it will not need a muffler.

There is going to still be energy that can be salvaged... this is because the gas will be hot. One way to get this energy is with a sterling cycle and another would be to say inject a bit of water into the gas to cause it to cool and contract.

The turbocharger does the opposite. It sacrifics fuel efficieny in order to obtain more power from the engine.

The articals on the Miller and Atkinson cycle should also be altered to reflect this observation. In fact, this is exactly what the Atkinson cycle engine is all about.

A good idea would be to calculate the exact amount of lost power given the boost. This will be determined by integrating the pressure verses missing stroke length because the greater the boost the greater the exhaust gas pressure when the exhaust valve opens. In non-piston engines - its still the same.

Some of this energy is going to be recovered by the turbocharger of course. It acts as a turbine and should be able to achieve about 55% efficiency which is pretty close to what the Brayton Cycle allows. Dumping that recovered energy back into compressed working fluid is ok but I suspect that not much of the energy is actually recovered in practice. The amount achieved in convetional engines should also be in this artical.

If the artical were to include this then I think it would be greatly improved and would be much more authoritive.

Another idea that might have merit is that if the turbine in the exhaust gas stream were to say run a generator then the electricity from this generator could be used to say crack water into Hydrogen and Oxygen which could be fed back into the engine as fuel. I don't know how much energy could be recovered this way. Nevertheless, the artical IMHO should be addressing these issues.

---

You made several good points, but a couple were incorrect:

If all the energy from the working fluid was extracted, it would be at atmospheric pressure AND temperature. Don't forget that gas law says they're related. There would be no leftover energy, assuming it was possible to have separate compression and expansion ratios to allow all the energy to be put to work. Even then, this theoretical engine could not run at a very high RPM, because of the inevitable stroke length and because the charge takes a certain amount of time to fully combust.

It's not possible to simultaneously have the exhaust at atmospheric pressure and ambient temperature. That would imply 100% energy efficiency. You can't do better than the Carnot cycle, so there's always waste heat left over whether there's a turbocharger present or not.- (User) WolfKeeper (Talk) 17:19, 3 February 2008 (UTC)

What the Miller cycle is about is compressor efficiency. A reciprocating piston is actually a horribly inefficient compressor, and the compression stroke is the least efficient cycle of the typical four-cycle engine. What the Miller cycle aims to do is use a better compressor (a mechanical supercharger) to do some of the work that the piston would normally do. That is why that engine is 15% more fuel efficient than an Otto-cycle one.

And in fact, that is why a turbocharged engine is still very efficient. The compression ratio of the pistons is lowered (they do less work compressing the charge), and a turbine takes over the rest. A turbocharger's compressor efficiency can be as high as 70-85%, and refers to how much energy goes into raising the pressure compared to how much energy is wasted as heat.

It would be ideal then, following these ideas, to have a piston-type engine with a compression ratio of 2:1 or even 1:1 and an expansion ratio of, say, 20:1 or higher, and have a turbocharger (or supercharger) do most or all of the compression. It would be like the Maxwell cycle on steroids. This way, the energy of combustion could be more completely used to turn the crankshaft instead of being wasted in another cylinder compressing the charge.

---

re:turbo/air intake if you increase the air intake to a turbo diesel engine and increase the exhaust size to remove emissions quickly would this improve fuel consumption

the fans who have their engines converted/turboed call the subject "forced induction" on forums, and the turbo kits available would usually have intercoolers to cope with overheating.

(!) An intercooler removes thermal energy from the asperated air caused by the pressure increase (a temperature differential increase is caused between the ambient and compressed air because there is more air in the compressed space) to allow more oxygen molecules into the combustion chamber at the same pressure. It is NOT installed to cope with overheating.

Now increasing the power of your engine would soon make you strenghten your brakes, then change your gearbox and put on flaps on the rear end to keep the back of the car pressed down escaping from lift off...

Fuel economy vs. huge engine?

I think it's worth noting that a turbo engine can achieve better economy with the same power, although possibly with a worse powerband if compression is lowered, than a larger engine. This is especially true for cars with aftemarket turbos, where fuel mileage remains unchanged in highway and careful city driving, despite the increased (peak) power. It is also worth noting that the brake specific fuel consumption (gal/hp, if you will, BSFC) of a turbo engine is often higher, but only under boost, due to the fact that richer air-to-fuel ratios are usually required to ward off knock and high EGTs.

A little peice of trivia is that backpressure can reduce stress on your connecting rods, or so I hear. I don't have anything to back that up though.

--Natesully 06:14, 27 January 2006 (UTC)

With a turbo, you are trading less brake specific fuel consumption at the top of the range for more efficiency at the bottom of the range. The reason for this is that the turbocharged car has to run richer under boost to prevent excessive EGTs. A large n/a engine can run relatively lean at full power without melting anything- this translates into lower fuel consumption at full power. The downside of the large v8 is that at even at very low rpm, the v8 has to consume a certain minimum amount of fuel to avoid misfiring.

My 1.8L + 18 psi miata gets about 30 mpg (out of boost) and makes 300-350whp (under boost) depending on ambient temperature. The downside of this is that if I operate the car at maximum power, I get far less fuel efficiency than a 6L v8 making those same amounts of power. In a long distance racing situation this would give an advantage to the v8 over time.

Beerslurpy 00:16, 16 June 2007 (UTC)

911 turbo info is incorrect.

Baldur said: "Please people, stop adding information that isn't factual. The Porsche 911 was not the first gasoline car with a VNT turbo!"

Well, I added the comment on the 911 and have re-added it since it is correct. The Porshe (997) 911 turbo is the first "high production petrol car" to have VGT turbochargers. Only 500 1989 Shelby CSX-VNTs were ever produced, including prototypes, that is not high production!

So Baldur please don't remove information that is factual. However if you can show me another HIGH PRODUCTON petrol car with VGT’s prior to the 997 turbo’s production let us know.

I'd just like to point out that in addition to the Shelbys, a number of other cars were made by Chrysler with the VNT. This includes the 1990 Shadow ES (141), Shadow Competition (27), Daytona Shelby (536), Daytona C/S (21), and LeBaron GTC (25). How many Porsche 911 Turbos were made in 1997? How do we distinguish production from high production? I'd argue that the Porsche 911 Turbo is NOT a high production petrol car, period, any more than a Dodge Viper is; and that in any case, the first PRODUCTION CAR to have a VNT was indeed made by Dodge a full 14 years before Porsche.

Additional: sorry, I am showing Porsche 911 turbo sales, according to Automotive News, at 291 units for the first ten months of 2005. Perhaps they sell double that number in Europe, but I fail to see how the Porsche 911 Turbo can be called high production while 1,250 Dodges are not. No shame in picking up a technology someone else has used before, and presumably making it better. (I'll add that this year, only 80 have been sold from January to October 31 in the US.) I always assumed "high production" started around 50,000 units.

the Dodge VNT turbos were "production vehicles" by any normal use of the word. 500 has been a standard homologation number for many sports that involve "production" vehicles. Also, I think that holding up the porsche 911 turbo as a "high volume production model" is a bit incredible. In truth, there have been no mass produced vehicles with variable vane turbos, at least not mass produced on the same scale as "cars using the Garret T3." There is no way you can count Porsche as the first user and not count dodge/chrysler. I love porsches, but the claim is simply not true.

Subaru

I'm pretty sure that Subaru doesn't make any sequential-turbocharged engines.

Fuel Efficiency section

I noticed the reference to a 'Clean Up' being required and at first wondered why - there seemed to be lots of great info.

However I feel that it is the tone of the Fuel Efficiency section in particular that is not up to encyclopedia standard. Some of the assertions about the air quality in California "forced" by running on a richer mixture (91RON petrol) sound a little suspicious. Firstly, does the engine management system adjust fuel mixture in response to pre-ignition detected by knock sensing, and to control combustion temperatures as suggested? Or, does the engine management system instead compensate by retarding the ignition timing (this is my understanding?)

Tone, by itself, is probably not important. But tone serves to indicate the calibre of the information. It is harder to trust information that is written informally or that targets a particular 'agenda'.

Thanks! -Alex 203.173.147.117 10:35, 23 May 2006 (UTC)

Agree with you, Alex. Also of course running a rich mixture doesn't exactly reduce emissions! Turbochargers nearly always run with higher octane because it greatly increases the power you get.

Note - use of higher octane is in order to avoid knocking 71.172.23.39 18:44, 28 November 2006 (UTC)

---

I fixed the section, but now I'm concerned that in order to accurately explain some of the concepts represented there I've had to repeat or redefine terms mentioned in other sections: Thermal efficiency, turbocharger sizing, intercooling and so on. I would really like to make some new sections devoted entirely to these specific ideas and eliminate some of the repetition throughout many parts of the whole article. Then I could add the section on blow-off valves without it being "tacked-on." What do you think? I appreciate your input.

-Brian

INTAKE OPTIMISATION

I've just got a new mazdaSpeed6 and Iam very pleased with it. I would like to modify the air intake but with more knowledge about volume and velocity of air requirements to really optimise the result. Any suggestions please

Denis

Shouldn't that be a topic for a forum somewhere and not Wikipedia article discussion? Also check under "cold air intake" and see if wikipedia gives you anything. 71.172.23.39 18:44, 28 November 2006 (UTC)

Note: There are serious technical inaccuracies in this section! First and foremost, a turbocharger does not necessarily increase the efficiency of an engine. While one can think of a turbocharged engine as having a higher "effective compression ratio" than a naturally aspirated engine, this does not mean that one can compare this "effective" CR to the CR of a naturally aspirated engine, for the purposes of calculating efficiency. Any engine generates power by doing more work during expansion than during compression. While a turbocharger does add more compression and expansion to the engine, the expansion cannot do more work than the compression because the turbine and compressor are mechanically connected! Also, since the turbo spins freely and isn't connected to the crankshaft, in a sense we could disregard the thermodynamics of the turbo and look instead at the engine itself, since that's where the drive power is produced directly. If we knew the pressure on the pistons at all parts of the cycle, we could calculate the indicated power of the engine and ignore the turbo entirely. Of course, the turbo will affect the pressure on the pistons, but how?

The efficiency of an otto cycle is independent of intake charge temperature, pressure, and density. For an idealized engine, we can directly calculate the work done, as a function of heat added during the compression and power strokes. The ratio of work done to heat added depends only on the engine's compression ratio, regardless of turbos or any other type of forced induction. In this sense, the turbo does not affect the efficiency of the engine at all. The turbo *can* affect the work done during the other two strokes, however - intake an exhaust. The boost pressure generated by the turbo actually does work on the pistons during the intake stroke, and this work contributes to the overall power output of the engine. And, since turbos necessarily generate exhaust backpressure, the engine must do work to push out the exhaust, which consumes power. So, the difference in efficiency between a turbo engine and a naturally aspireated engine depends on the relative boost pressure and exhaust backpressure. If boost and backpressure are equal, the ideal engine's thermodynamic efficiency will be exactly the same as a naturally aspirated engine with the same compression ratio. If boost pressure exceeds backpressure, the efficiency will be higher. If backpressure exceeds boost, the efficiency will be lower. An ideal turbo, with isentropic compression and expansion, fitted to an ideal engine, should generate much higher boost than backpressure, so this would tend to increase efficiency. This is related to the much higher temperature (available energy) in the exhaust than the intake, and also the energy which is lost during exhaust blowdown in a NA engine, which the turbo can recover. However, real engines differ from these idealizations.

In practice, the turbine and compressor efficiencies of a turbo are not 100%. Additionally, there is a large heat loss in the exhaust, and there is friction in the turbo assembly as well. Experience shows that modern turbocharged engines are generally split on whether boost is higher than backpressure, or the other way around. Small turbos which spool quickly tend to require higher backpressure, and thus tend to lower engine efficiency, whereas large slower-spooling turbos require less backpressure and can raise the engine's efficiency. However, due to knocking limitations, turbocharged engines tend to run significantly lower compression ratios, so it can be generalized that real turbocharged engines tend to have somewhat higher brake-specific fuel consumption (BSFC) than real naturally aspirated engines.

However, turbocharged engines clearly tend to have a lower mass for the same power output, compared to a comparable naturally aspirated engine. So, if the engine is going into a vehicle where the engine is a significant fraction of the vehicle mass, the *vehicle* efficiency can be higher with a turbo engine, even if the *engine* efficiency is lower (this would especially be true in aircraft).

The section about enriching the fuel mixture does not make much sense, and is poorly written in my opinion. It is true that enriching the mixture can allow the engine to make slightly more power, by staving off knock and allowing slightly higher boost or more advanced ignition timing. But, this is far from necessary in a well-designed turbo system, and will most definitely increase BSFC. A turbo engine at the limit of knock running an equivalence ratio of 1.2+ is *not* a good design for a passenger car. —Preceding unsigned comment added by 192.35.35.34 (talk) 22:16, 26 March 2008 (UTC)

Additional comments by same author:

At part-throttle and at idle, turbo engines tend to be more efficient than NA engines of the same peak power. This is mostly because the turbo engine will be smaller displacement so will have lower intake pumping losses when the throttle is not wide open. —Preceding unsigned comment added by 128.253.53.154 (talk) 20:25, 10 April 2008 (UTC)

Subaru sequential turbo

Subaru produced a Legacy sequential turbo car for the JDM. It had two dissimilarly sized turbos, one for low speed, and one that kicked in at higher load and RPM. They no longer produce this car, nor any other twin/sequential/bi turbo cars. Reference: Forced Induction Performance by A. Graham Bell

I believe this was the Legacy RSK - specs here http://specs.amayama.com/specs-subaru-legacy-b4-1998-december/28469/

Revivions today.

Revisions today:

The exhaust side of a turbocharger is NOT an impeller! It is a turbine. They are opposites, not synonyms. I reworded the article to correct the error. Impellers compress gases. The turbine in a turbocharger is actually decompressing the gas, and that is partially how it extracts energy. The pressure differential across the turbine plays a big part in the energy it extracts. Reference impeller and turbine. Yes, they look about the same, but are different terms and desparately need to be separated.

Took out "sometimes" about speed. It's incredibly typical for turbochargers spin at greater than 100,000 rpm. I'd say darn near every gasoline turbocharger does (besides the most enormous models), and some diesels as well. You can look at about any turbocharger compressor map.

Turbochargers do not compress air in the intake manifold like a Roots blower. They compress the air in the compressor housing, like a Lysholm/Whipple or any other centrifugal supercharger. I reworded this section to more accurately reflect this. I think describing the relationship of the volume flow of the engine to volume flow of the compressor makes far more sense and avoids inaccuracies while still being clear about the relationship of flow and boost pressure. A turbocharger doesn't just "blow" air like a roots blower. There is an important distinction.

Speed of the turbo is not just directly proportional to boost only. It is also proportional to mass air flow. Reworded this as well. That is, 15psi @ 3000rpm and 15 psi @ 6000rpm are very different speeds for the turbo! "directly proportional to boost" implies way too much of a linear and relationship. You may look at any turbo compressor map for verification.

Wording "for example" seemed out of place. It isn't just an example, it is the general case. I wanted to work a link into volumetric efficiency since it is an important concept.

Also worked in a link to wastegate when talking about controlling the speed of the turbocharger, since it really should be mentioned as pretty much the sole means of boost control in any modern turbocharged engine system. No one in their right mind uses intake restrictors or boost dumps anymore.

Fuel Efficiency Question

This extra waste heat combined with the lower compression ratio (more specifically, expansion ratio) of turbocharged engines contributes to slightly lower thermal efficiency, which has a small but direct impact on overall fuel efficiency.

I'm a little confused here, why does the compression ratio drop with the addition of a turbocharger to the engine? Is it that since the intake air is at higher pressure, you need less volume of air to equal the same mass of air in the combustion chamber? And if this is so, why can't you just program the engine to have a constant compression ratio, regardless of the incoming air pressure? Is it a mechanical limitation, i.e. the combustion chamber can't withstand a higher pressure? Just wondering... - Runch 18:30, 14 August 2006 (UTC)

Answer to above

The compression ratio doesn't drop automatically with the addition of a turbocharger, but it generally is separately chosen to run a lower compression ratio on any forced induction vehicle.

Since air pressure is increased, cylinder pressure at the same compression ratio will drastically increase. To keep the engine from detonating and/or pre-igniting simply due to the temperature jump of the compression stroke with the extra air (see ideal gas law, charle's law, boyle's law), a turbo car will have a lower static compression ratio compared to a naturally aspirated car. Consider a turbocharged 2.5L I4 running 1bar with a good intercooler may have nearly double the air molecules in each cylinder as a 5.0L V8 producing the same power.

You cannot "program" compression ratio. Static compression ratio is a physical measurement of the displaced volume of the stroke and bore vs. the combustion chamber size with the piston at top dead center.

I think Saab did some development on a car which could change its compression ratio on the fly, but I'm not sure it made it into a production car. For 99% of cars out there, changing compression ratio requires rebuilding the engine with different pistons, rods, and/or crankshaft.

If you could change compression on the fly, yes, you would want to run high compression just tooling around town or cruising, and have it drop at higher load, based on air mass load per cylinder per rev. This would have a very positive benefit for turbocharged cars with regards to fuel efficiency.

Every car's compression ratio is a balance of fuel efficiency and detonation and preignition resistance at high loads. High performance turbocharged cars have a particularly wide range of load from cruising/idling to full throttle operation. Thus, a typical 2.0L turbocharged car is going to have to give up some fuel efficiency compared to a naturally aspirated 2.0L engine so it won't blow up when the turbo kicks in and supplies double the air and double the power.

Thanks! - Runch 04:15, 15 August 2006 (UTC)

This is also why turbos tend to use premium gas!

You cannot change the compression ratio by changing rods, shorter rods have disadvantages over longer rods in terms of performance. While destroking the engine will reduce the compression ratio the main purpose of that is to reduce the piston speed and thus increase top end performance. There are 3 methods of altering the compression ratio of an engine. Most common is to fit different designed pistons, another option is to fit a head gasket of a different thickness. Third option is to replace or modify the cylinder head to alter the volume of the combustion chamber. --Baldur 23:16, 30 November 2006 (UTC)

pump

Why the mention of a pump? Can you turbocharge a pump? If the turbocharger is driven entirely by the dynamic pressure of the exhaust then I would guess it would be less efficient than a mechnically driven supercharger. The big advantage of a turbocharger is it's ability to convert heat into mechanical energy. Taking mechanical energy from the engine in the form of the dynamic pressure of the exhaust has to be less efficient than using a gear or a chain. --Gbleem 15:50, 8 February 2007 (UTC)

Exhaust gas heat, velocity, and pressure are otherwise completely wasted out the exhaust pipe in a crank-driven supercharged or naturally aspirated engine. Using crank power to compress air directly removes torque at the flywheel. Power used by the compressor is exactly what is removed from the crank. When the exhaust passes through the turbine, its energy is reduced, which accounts for the energy needed to compress the air. The extra back pressure created by the turbine may require some crank power to push gas out of the cylinder, but that is not what accounts for ALL of the energy used by the turbine. Some, or probably most, is taken from wasted energy in the exhaust stream. From there it becomes difficult to directly compare because a turbo car will have different cams and manifolds compared to a blown car. Also, the impeller-based compressors used on turbochargers are much more efficient than a typical roots blower which creates a lot of heat in the intake charge. Some belt drive superchargers use what looks like half a turbo because of this. Lysholm blowers are closer to turbo efficiency, but still take all energy from the crank. --Freonr2 03:50, 16 February 2007 (UTC)

I think you are agreeing with me. My thought was that if the only energy was to the turbocharger was provided by push of the engine on the exhaust then there would be no advantage to using a turbocharger instead of a supercharger. --Gbleem 14:12, 23 February 2007 (UTC)

generalization

I did a quick search and found that turbochargers are also used to recover energy in other applications besides internal combustion engines. It seems like they may be recovering more than heat energy. I think the article needs to discuss turbochargers in general and have a section on turbocharging the internal combustion engine. --Gbleem 00:38, 10 February 2007 (UTC)

Well, that would just be a turbine powered generator, not a turbocharger, would it not? Check out turbine, gas turbine, etc. --Freonr2 03:58, 16 February 2007 (UTC)

No. For example you use a lot of pressure to run water through a reverse osmosis process. When it comes out the other side it has velocity and heat. You recover the velocity and heat with a turbocharger that helps the pumping of the dirty water comming into the filter. --Gbleem 14:08, 23 February 2007 (UTC)

New introduction

I replaced the previous introduction for the following reasons:

1. It contained inaccuracies. 2. I think it was to technical. I would be better to explain the thermodynamical principles of a turbo charger in a seperate section of the article.

Please discuss. Ζεύς 11:59, 9 March 2007 (UTC)

The article should be about turbochargers in general, not just automotive turbochargers or internal combustion engine turbochargers. --Gbleem 08:57, 8 April 2007 (UTC)

What examples of a turbocharger can you provide that's not used with an internal combustion engine? Just keep in mind there are other articles for somewhat similar (but different) ideas like gas turbine, turboexpander, etc (see turbine for lots of examples). Let's not overlap or try to redefine what the term "turbocharger" means when there are different industries using only "similar" devices, but have different names. --Freonr2 21:52, 12 April 2007 (UTC)

One example. A company that makes them. another document --Gbleem 09:39, 13 April 2007 (UTC)

Optimum Air-Fuel Ratio

"The optimum Air-to-Fuel ratio (A/F) for complete combustion of gasoline is 14.7:1" Does this refer to the stoichiometric A/F ratio? If so, surely different forms of gasoline will have different stoichiometric A/F ratios? Also, in the context of internal combustion engines, the optimum ratio for complete combustion will be on the lean side, and the ratio at which the highest possible amount of combustion occurs will be different for every engine design, depending on valve and spark timing, cylinder geometry etc. I think the definition of optimum should be better defined here, or that particular A/F should have a reference. And it should be clear that the A/F is given on a molar basis, as A/F by mass is also used. Perhaps "Stoichiometric fuel ratios for the combustion of gasoline tend to be approximately (insert ratio here) on a molar basis" would be more encyclopedic? —The preceding unsigned comment was added by Howboutpete (talk • contribs) 00:43, 15 April 2007 (UTC). Forgot to sign Howboutpete 00:44, 15 April 2007 (UTC)

Changed it to stoichiometric, but am still unclear about what is trying to be said in that section of the article. What part of it is relevant to turbochargers and why? Howboutpete 15:07, 18 April 2007 (UTC)

Not having read the article thoroughly, I'd say it's relevant because you create power by burning fuel. More power can be created in the same displacement by increasing the volumetric efficiency -- by adding more gasoline and oxygent -- and one of the common ways to do that is to use forced induction... if the A/F ratio did not need to remain constant, forced induction would not be required. It's a side point, but people looking to learn about forced induction will need to be introduced to it (and then likely pointed at a more detailed article for further information). -- Upholder 15:27, 3 May 2007 (UTC)

Cleanup on the horizon

To the above comment: I think it should be left to an article on A/F ratios. All that's needed here is "The increased density (and hence increased number of molecules per unit volume) of the inducted air means more fuel can be burned at the same A/F ratio. However, turbocharged engines will normally run leaner mixes to reduce the level of knocking that the increased pressure and temperature of the intake charge will induce." Perhaps this would flow nicely into a brief explanation of intercoolers. Anyway, this article is absolutely massive, and digresses on points that are just a click away, like A/F ratios for example. It's so full of good information that anyone looking for a particular piece of good info will get lost. I'm going to leave this comment here for a while before I make any changes so as to allow the third opinion guy below to do his thing, and allow others to disagree with me. But at some point I'm cleaning this thing up. Howboutpete 19:22, 3 May 2007 (UTC)

I think you're right. If you'd like to go ahead and trim material that is either duplicated in related articles or better placed in those articles, that would make it easier for us to improve the other issues that are affecting this article. I'll hold off from making any edits to give you time to make some changes. Adrian M. H. 19:51, 3 May 2007 (UTC)

Repeated POV edits

202.41.72.100 is severely hurting the quality of this article with his edits. I'm not sure if they constitute vandalism, but they are full of POV and normally replace good material. Howboutpete 06:02, 30 April 2007 (UTC)

what you have edited says there are absolutely no disadvantages of turbocharger, which is purely commercially motivated. there is only one reason why turbochargers are avoided in petrol engines and you are removing that, or mention the reason why ferrari dont use turbocharger? reverting your edit. and most obviously suprecharger has more boost which is not POV, its a fact either true or fault202.41.72.100 06:51, 30 April 2007 (UTC)

"But achievable specific power output is more in a supercharged engine." Incorrect, BMW got 1300hp from a 1.5L turbocharged engine in the 1980's, the achievable power output is unlimited if you can put up with the lag. The bugatti veyron's main design criterion was high power, and turbochargers were chosen. "Boost is not as much as a supercharger hence design considerations are less." Boost with respect to what variable. Design considerations are less means what? "Throttle response is directly related to driving pleasure, which is missed in a turbocharged engine. Hence turbochargers are generally avoided in petrol engines." Again wrong, antilag systems and various turbo set-ups have reduced lag to negligible levels. Check rally cars for example, or their road car equivalents. And why did you have to say petrol? Because diesels almost all have turbos now? "(around 1200-1500rpm" Completely dependent on the particular engine design, fuel type, and turbocharger type. Unsourced. "Sudden lack of power below some rpm is not a desired characteristic." It is a sudden increase in power that characterises the problem, who cares about/notices power on deceleration? Instead of saying "is not a desired characteristic", it should tell about what exact problems it causes, like sudden oversteer in cornering, or low torque at low rpm. Is not desired by who?

I removed references to superchargers as it is a turbocharger article and the advantages/disadvantages should primarily be with regard to turbo vs. n/a. Turbochargers are not avoided in engines any more than superchargers are. Superchargers only have more boost in high power engines and stating that they have more boost in general is therefore implicitly POV. Anyway a turbocharger system with the same boost as a supercharged system will produce more horsepower, but I did not choose to add this as it is irrelevant to the article. And the last time Ferrari used forced induction was in the F40, which was turbocharged. They stopped using turbos when F1 banned them due to excessive power outputs, as the top end Ferraris were loosely branded as F1 cars for the road. I'm sorry for my previous comment, as looking at your edits in more detail I think they were in good faith, but I still think they don't belong in the article, and so I am removing them again. And for your information i have no commercial motivation, and am unbiased. Superchargers are good for some applications, turbochargers are good for others, they are rarely in competition for a single application however, so the comparison is irrelevant. Howboutpete 13:03, 2 May 2007 (UTC)

created driving pleasure pageVinay412 04:14, 3 May 2007 (UTC)

changes: 1.for your kind information its boost-threshold, not lack-of-response, which may result in oversteer(in rear wheel drive car). 2. and specific power is more in both petrol and diesel engines. 3. and how it recovers energy from exhaust is explained properly. and could you please explain why 95 % of factory made petrol cars do not have turbochargers, i will include this when i get proper reference. thanks202.41.72.100 04:15, 4 May 2007 (UTC)

I'll try to find a source on the boost threshold/lag thing. Yes, specific power is more in both engine types, but that quality is used more in diesels as their specific power is lower than petrol engines, and due to their heaviness an increase in displacement (up to say a point where efficiciency was equal to a petrol engine) would render a car sluggish. That's why diesels usually are turbocharged. A source for this would be easy to find as it is common knowledge, and I suspect you know that anyway. As for your other changes, I'll leave them as you're only going to change them again, but eventually they're going unless you adhere to the third opinion below. Howboutpete 11:36, 4 May 2007 (UTC)

To be frank these days word "lag" is used for both boost-threshold and lack-of-responsiveness, notice it mentioned section lag: "Lag is not to be confused with the boost threshold; however, many publications still make this basic mistake". here many dont understand what is lack-of-response and get confused that its something related to boost-threshold. lack-of-response(lack of driving pleasure) is the only reason why turbo is avoided in petrols(even for next 100 years) and this essential info must be entered in section.122.167.140.36 14:23, 4 May 2007 (UTC)

I had hoped that you would do what I asked below: that is, to list the statements that you think should be included in the article and provide reliable sources for them. Verifiability policy requires that facts must be attributable. If you don't do that, then Howboutpete is within his rights to remove any material that is unsourced and potentially questionable. Adrian M. H. 15:59, 4 May 2007 (UTC)

mr. adrian, he added some content if you have noticed, and has he given you any references? you look second party than third. it is a scientific subject it requires some basic knowledge which you seem to badly lack, where next sentence is derived from earlier. thanksVinay412 07:12, 5 May 2007 (UTC) and most sentences in advantages and disadvantages are quoted or derived from design details section which is already properly sourcedVinay412 07:14, 5 May 2007 (UTC)

Firstly, please use my correct name. Secondly, I requested that the proposed material be placed here, on this talk page, because that is what we do with proposed material. WP:3O does not work like that, and what is more, it is for the resolution of a dispute between two editors; if you are involved in this dispute , that needs to be made clear and the issue should instead be dealt with by WP:RFC or similar. Thirdly, the comment "...requires some basic knowledge which you seem to badly lack" infringes on NPA; I have already stated that I have a good level of mechanical knowledge and you are grossly wrong to claim otherwise. The comment "you look second party than third" clearly violates AGF. Fourthly, the article is still not satisfactorily sourced! There are still only four references, and that does not constitute cited sources. In light of your attitude and disrespect, I will not proceed any further with this resolution process. I have better things to do. Adrian M. H. 14:20, 5 May 2007 (UTC)

Dear Adrian, these days there are too many reference seekers in wikipedia, who seek reference over head of every sentence. when some sentences are derived from another sentence that does not call for a reference. and you claim does not mean you have knowledge and i dont trouble myself to interconnect each sentence in the article. it was nice time with you, byeVinay412 06:39, 6 May 2007 (UTC)

Third opinion

In due course, I will try to go through the article and tag with {{fact}} any statements that are unsourced and may reasonably be questioned. I have good technical knowledge, but I will have to consider Joe Average's viewpoint. I have to say that four refs for an article of this length is just not up to standard. Anyone who was strict with their interpretation of WP:V would remove about three quarters of this article.
In the meantime, I suggest that the anon user at 202.41.72.100 place his/her material here on this talk page and provide reliable sources. Material that is suitably referenced can go in. If you cannot find a source, then it stays out. Simple as that.
Disputes such as this are (controversial cases excepted) usually quite easy to resolve if everyone pays heed to the key policies about attribution and reliable sources. Adrian M. H. 17:50, 3 May 2007 (UTC)

Generalization part 2

Can we at least mention in the beginning that there are other uses for a turbocharger besides internal combustion engines? --Gbleem 00:43, 3 June 2007 (UTC)