turbocharged or supercharged?

Hey guys I got two questions. What is the difference between being turbocharged and supercharged? (If threre is one) And my Mom just bought an Audi TT quatro and the thing has an "I4 turbo" engine. does she need to worry about boost pressure and/or other regular maintenance on the turbocharged egine, or is she gonna be fine (since SHE's not gonna be driving it all that hard, its me shes gotta look out for...:runaround: )

Google (or wikipedia) is your friend...

Basically a supercharger is run off the engine and a turbo is run off the exhaust...

Of course there are other differences (IE: a turbo only uses centrfugal blades vs superchargers could use centrifugal or roots-type supercharging, it's more prominent to intercool turbocharged systems, etc...)

The second question: Depends on how you drive. On a stock tune you don't need to worry about boost pressure (unless you are worried about turbo lag when passing someone), however I don't think the Audi's have electric driven water/oil pumps yet so you will still need to let the turbos "cool down" if you drive it hard before turning the engine off.

Edit: WRT maintenance... Be aware that oil in general breaks down faster in Turbo's engines then N/A because it has to run past the Turbo (and hot exhaust) to cool it. So pretty much increased maintenance has to do with effective heat management (check coolant and oil more often).

And of course when the car get's older, checking for boost or vacuum leaks...

:1:

an "I4 turbo" engine is an Inline 4-cylinder engine (all the cylinders in a strait line as opposed to a "V" configuration, like in our V6's) There are also other configurations, such as "W" and boxer.

like 2old said, a turbocharger uses the hot exhaust gasses to spin one side of a turbine wheel, making the other side of the turbine pressurize the air going into the engine, making more air fit into the combustion chamber, yielding more horsepower. A supercharger has the same result, but is hooked directly to the engine by a belt.

one of the most important things to remember with a turbocharged engine is to keep up on oil changes and use good oil. i use mobil 1 and change my oil every 2000 to 2500 miles.

Here's a good thread about the two. If you ask me though, turbo is the only to go.

http://www.automotiveforums.com/vbulletin/showthread.php?t=201348

Thanks guys that totally clears up all misconceptions I ever had about the two. Just to clarify, as long as my mom doesn't drive it hard, there shouldnt be any extensive maintenance that she needs to keep up with (besides the oil changes) right? Cuz she sure as hell wont know about it if there is, so Im asking yall so I can tell her what she needs to keep up with. Thanks again guys

Change the oil and filter every 3,000 miles no matter what. Try to use a good synthetic motor oil. Also, always let the turbo cool before shutting off the car.

So let the turbo cool as in drive around in low rpms fora while so the turbo doesnt kick in too much, or let the turbo cool as in park it in the driveway and let it idle for 15 minutes before shutting it off?

Just a light throttle for the last 5 minutes before turning off is needed...

It's of course better if you let it idle for 5 minutes, but if you mom is driving it, it should be okay unless you live on a hill and/or she has a lead foot.

unless your driving aggressively, you really dont need to worry about it too much. My turbo timer has an auto mode, which basically decides how long to idle the car depending on how you have been driving. Under normal circumstances, by the time i wait at a few lights and cruise through my neighborhood, the timer is already at less than 30 seconds by the time i get home.
Unless you're ripping around right before you park it, a minute should be more than addequate. The most i've ever had my timer give me in auto mode is about 3 minutes, and that was after an aggressive 10 minute highway run and then ripping around some side streets.

I don't think your mom needs to let her car idle before shutting down at all. Unless you are running an older turbo car or higher amounts of boost, your turbo isn't going to get that hot. Having said that, I would say the same thing other people have said already. Just stay out of the boost for the last few minutes of driving and you will be fine.


BTW 15 minutes of Idling!?!?!?! Holy crap. I expect the Sun to burn out before then.

It doesn't matter how you drive or how old your turbo is you should always allow the car to idle for at least 30 seconds before shutting it off and if you've been driving hard then you should take it easy for five minutes then let it idle for 30 seconds before shutting it off. Those impellers can reach speeds well about 100,000 RPMs. You would be surprised at how hot they get even during normal driving. The problem is that if you don't do this the oil will basically boil inside the bearings, it will become a magnet for dirt and debris and will cause premature bearing failure.

I think 30 seconds is worth having your turbo last. This is how I take care of all my turbo-charged cars and my first GTC had 152,000 miles on it when it was totaled. No shaft play, no smoke, smooth rotation, and boosting 14 PSI with no problem. I'm sure the turbo is still being used by the lucky bastard that got it at the junk yard.

*steps off soap box*

you forgot about the decreased oil flow due to the deposits formed from the oil "coking" :wink:

lol

I was told that my car had some liquid cooling that occurs even after the engine is shut off. No big deal for me. It takes me about a minute to get my garage open and pull in. I don't see how the turbo would get hot if it's not boosting?

I was told that my car had some liquid cooling that occurs even after the engine is shut off. No big deal for me. It takes me about a minute to get my garage open and pull in. I don't see how the turbo would get hot if it's not boosting?

You might have a water cooled turbo in which it is connected to your coolant system. However, it would not work after you shut off your car. Whoever told you that doesn't know what they're talking about. Have you ever heard of the exhaust side of the turbo being called the hot side? It isn't just a clever name. There is ALWAYS hot exhaust gases running through the turbo.

Trust me, it's hot and if you want your turbo to last then you should take my advice.

You might have a water cooled turbo in which it is connected to your coolant system. However, it would not work after you shut off your car. Whoever told you that doesn't know what they're talking about. Have you ever heard of the exhaust side of the turbo being called the hot side? It isn't just a clever name. There is ALWAYS hot exhaust gases running through the turbo.

Trust me, it's hot and if you want your turbo to last then you should take my advice.

Are you threatening to hurt Bunny?? I am afraid I can't allow that. But if what you say is true, the turbo would still be hot if you left it idling with exhaust gases running though it.

The problem is the amount of heat escaping to the turbo housing relative to the amount of oil cooling it.

Think of it this way... It's easier to cool a 100 degree drop of water then a kettle of water. A drop being idle and a kettle being WOT.

Right now I think the only car that you can shut off right after hard driving is the BMW 335. This is because it has a electric water pump that can run when the engine is shut off (the turbo is water cooled) and prevent heat soak.