Tag Info

Hot answers tagged

16

tl;dr: They do. It's just harder to tell how much. The longer answer is that they do and that effective compression is failing you as an approximation for actual effects. Think about detonation (AKA premature ignition of the fuel-air mixture). Normally we consider two causes: compression (the change in the space enclosed by the cylinder as the piston ...


15

As has already been noted, anything rubber will have perished and will need replacing, as will all the fluids and any other normal perishable items (brakes, battery, filters etc). The brakes will have siezed on, and depending how dry the garage was, the interior may have mould and the bodyshell may have gone rusty... The biggest risk, however, is that the ...


14

There are a few important factors at play here. Hot air rises, cold air sinks In physics-speak, hot air is less dense than cold air. This means that the volume occupied by 1 kg of hot air is greater than the volume occupied by 1 kg of cold air. The internal combustion engine is a volumetric device What this implies is that every time the engine turns ...


9

Let me lead off with an excellent book on the topic: Corky Bell's Maximum Boost. There is a sound treatment of the basics of turbocharger operation in addition to some dated and esoteric applications that are still interesting. For example, I find the discussion of turbocharging different types of carburetor to be of intellectual if not practical interest. ...


8

Sounds to me like the car is suffering from a boost leak - either the plumbing has a leak somewhere or the wastegate doesn't hold pressure properly. Does the car have a boost gauge and if it does, can you see if you're losing boost at the same time you get the noise? Normally you'll have a hard time hearing the wastegate if it's an OEM one as they all ...


6

Both turbochargers and superchargers perform the same function: compress air that will be fed into the engine. In other words, they are glorified air compressors. As with any compressor, both need energy in order to compress the air, which is where the difference between the two devices becomes relevant. Superchargers are belt-driven or chain-driven, so ...


5

Turns out the previous owner of the car adjusted the wastegate actuator in an attempt to increase boost pressure. The sudden loss of boost came about because the ECU forced the wastegate open in an attempt to keep the manifold attached to the engine ;) Kudos to whomever wrote the software for the Bosch Motronics unit.


5

You can't prevent the turbo from spooling up without physically removing it from the car. Depending on how the boost is controlled (ie, if there is a manual or electronic boost controller involved, too, or if it's just standard boost control by the ECU) you might be able to turn down the maximum boost to the pressure controlled by the spring in the wastegate ...


5

Several reasons: First: Diesels have a very simple operation which is basically more air, more fuel = more power. On gasoline engines you have to worry more about running too lean, too hot, having incorrect timing. And, you generally already have enough air. You run at higher RPMs and suck in more air. Gasoline is much more volatile than Diesel. It burns ...


4

You pretty much guessed it, and if you didn't wikipedia is your friend. In summary, turbocharger operates by having two turbines connected to the same rotating axis. One turbine is spun by the exhaust gases, which cause the other turbine to spin. The second one is what forces the air into the intake of the engine. At idle rpm, there's barely any exhaust ...


4

The turbo shouldn't have any effect here after the first fraction of a second - a turbo runs off exhaust gases so with your foot off the accelerator it will spin down, and thus giving no forced induction. I don't know if there would be an effect with a supercharger, but I'm guessing not much. The difference in size will have an impact though 0.2 of a litre ...


4

One of the reasons that a turbo setup with the equivalent effective compression is more forgiving of low octane gas than than a static compression setup is that you're not at that compression ratio all the time. Take that honda, for example. At 9:1 static ratio, you can run 87 octane all day as long as you don't push any boost at it. When you do start ...


4

If you have a highly tuned performance car you are told to idle for a few minutes before you roll up to the pump, otherwise you can destroy your turbo. I regularly see other tuned Japanese cars idling while i do this. It's also a good opportunity to talk cars with other petrolheads.


4

You should whenever possible let the engine idle for a short period of time to allow the turbo to cool in big trucks and cars alike. It will definitely add life to your turbo. If you are keeping relatively low speeds and minimal boost in the last few minutes of your drive such as in your neighborhood or long driveway then the time needed to allow the ...


4

Actually running rich is less dangerous than running lean. I don't know specifically about Subaru, but in general, running lean can cause detonation more easily. And yes, while 14.7:1 is the stoichiometric ratio deemed as perfect for an air fuel mixture, running rich has the big advantage of reducing the chances of pre-ignition or pinging. In a turbo car, ...


3

I drive a gtc turbo and had the same problem. Check all the rear and front boost pressure/solenoids and their connecting rubber hoses and pipes....I spent lots on replacing parts, until I found a perished hose connector on the rear boost solenoid... never had a problem again... in fact I'm pushing 166kw on the wheels with no mods :)


3

The letters are standard: Park Reverse Neutral Drive Sport (or possibly Snow - thanks @Brian) Braking (usually for going down hills) None of these have anything to do with 4WD or 2WD selection. If your Daihatsu is the 4WD version, it is permanently 4WD - there is no selector on that spec of car. It was a specific Japanese edition. You have stated ...


3

Two possibilities occur to me: a too-large turbo or a too-loose wastegate. when I press the accelerator there is no power until the rpm tachometer reaches 2500 This almost sounds like the replacement turbo is too large. when I press the accelerator there is no power until the rpm tachometer reaches 2500, then I need to release the accelerator ...


3

I would suggest checking the owners manual to see what Sabb requires for a minimum octane fuel.It should be 93 octane for your motor.That being said higher octane fuel will not help the turbo last longer.Octane ratings are a measure of the fuels ability to resist engine knock.Engine knock is caused by fuel ignition with the piston in the incorrect ...


3

You'll need to check/replace for all rubber hoses(brakes, power steering, radiator, vacuum,...) as they could have dried and may break under load. Check wiring, they could have corroded or dried and can cause shortcut. Grease parts (Drifeshafts, steering, ...). Get a factory service manual for your specific vehicule and check the maintenance items, they ...


3

I wouldn't rule out a bad MAF so quickly - there was a generation of VW and AUDI MAFs that slowly went south without any indication from the ECU that they were doing so and IIRC the ECU managed to compensate for the dying MAF for a while. Also, if the ECU thinks you might be boosting at 15psi and using a conventional gauge suggests you're boost 7psi, you ...


3

In addition to good answer by @Bob: There are some tricks that can be used to ease the problem: A knock sensor for detecting premature detonations (and adjusting boost pressure). E.g. Saab APC allows safe use of lower octane fuels. Injecting water to cool the combustion chambers (instead of excessive fuel) Per cylinder exthaust thermometers (and ...


3

The waste gate is designed (as you'll see in Bob's excellent answer to his linked question) to avoid spinning the turbo up unless needed. This saves fuel and wear. The blow off valve or dump valve is designed to stop a compression wave passing back into the turbo when you close the throttle, as this wave could stall the turbo completely, which can put high ...


3

You've understood how they work, now you must think about "when" they work to understand why they're there. A turbo utilizes the exhaust gas to spin a turbine which which is mechanically coupled to another impeller on the intake side which forces air into the engine. As the engine produces more exhaust, the turbo spins faster and produces more boost until ...


3

In your case if it's diesel it has a turbo, if it's gas it doesn't. At least from the factory. Now that is specific to the year make and model in your question. As for what they look like. Nick has a good explanation. In this picture it's just to the left of the long green tube in the middle of the picture. That tube is connected to the turbo by a short ...


3

The only cars with turbocharges which do not have air filters are race cars. They do it this way so there is absolutely no restrictions on the intake tract. Race engines are routinely rebuilt as needed, so are not worried about small particulates entering the engine. Normal street driven vehicles will all have air filters on them, and as long as those air ...


3

A turbo is a type of supercharger. Superchargers all compress the intake air before pushing it into the engine. A turbine-supercharger (aka "turbo") is powered by a turbine wheel connected to the exhaust. Other superchargers are driven via a pulley system directly from the engine. That's all really. Conceptually speaking, a centrifugal supercharger and ...


3

Do you have any idea about potential power level of 132 kW (180 HP), 700 Nm MAN truck (TGL) 4.5 litre engine with damaged (not working) turbo? As a rule of thumb, for every atmosphere's worth of boost, you'll double the amount of power the amount the engine puts out naturally aspirated. For instance, if an engine puts out 100hp naturally aspirated, the ...


3

As stated in the comments, it's a lot cheaper to remove excess weight. If you use this car as a daily drive it's best to keep stuff like a spare tire and jack in your car.. Start with the easy stuff: a lot of people have a lot of stuff in their car that they'll never need. If you want to make the car even more lighter, you could opt to remove the rear seat ...


2

This is solvable at the ECU: one of the profiles that I could install using my AccessPort is called "valet mode." The performance is severely limited in that it prevents boost and significant speed. Caveat: going this route would cost you hundreds of dollars. Admittedly, I really like the performance aspect of the AccessPort and that's why I purchased it. ...



Only top voted, non community-wiki answers of a minimum length are eligible