It would seem that a high RPM, small high-output engine (for ex. Subaru WRX STI or Mitsubishi Evo) cannot last too long. The stress on its components is just too much. Can such an engine last, say, 150,000 miles without major repairs? Is there any special, expesnive maintanance that a turbo engine requires?
Why do you think they are high rpm ?
The whole point of turbos is to avoid the need for high revs.
Graham
I see. So, does a small, high output turbo engine require special regular servicing?
Small ? Like how small ? My own experience is limited to Saab engines of 2.0 -
2.3 litre displacement. In 'hot' factory tune these can develop up to 300 bhp. Race tuned ones are good for up to 400 bhp but you have to be careful not to melt the piston crowns.The use of synthetic oils is highly advised.
Graham
Use a high quality oil like mobil 1 and change it per the owners manual. Try to operate the vehicle per the owners manual with regard to the turbo, letting it cool down etc if so specified.
That's it as far as I know.
Uhh, no. The point of turbos is to recapture lost energy.
The more revs you run, the greater the volume of air you can push, and the more fuel you can burn. High revs is where the turbo does its best work.
DAGS on turbocharging to learn something on the subject.
E.P.
The 2.2L Audi I5 runs a K24 turbo and pushes about 15lbs boost, max, in stock form. Modifiying the ECU will allow the turbo to push 20-24lbs boost.
There are I5 Audi turbo engines well over 200k miles on stock internals, with original turbos. This is not unusual.
The only special maintenance required is regular oil changes with high-quality oil (synthetic, most likely) and a five-minute cooldown after a high-boost run. Oh, and try not to push a lot of boost until the oil is warm.
The run it. :)
E.P.
No it isn't.
It's to 'push' more fuel-air mixture into the cylinder.
The rev limit for a blown and unblown version of the same engine will be the same though.
DAGS ?
Graham
True, but that's more to do with the drivers they attract, not the engineering. In a UK city, you actively avoid Subarus when driving, simply because of the mouth-breathing Burberry-clad oiks they attract.
Saabs are quite unrepresentative ot turbos too. Low pressure, relatively low performance (compared to a Scooby) and mainly not tending to be driven by hooligans either.
2 liters is small. 300 horses on a FWD car? That's a waste of horsepower.
AFAIK, nobody races in FWD cars.
I got 480,000 miles on a Chrysler Laser without any real engine maintenance. It took five transmissions to get that far, though. I never got it up to
500,000 because I got fed up with the constant transmission work.Not if you drive it gently. For the most part, modern engines are designed carefully with proper reinforcement of parts that need to take a lot of stress. The engine is designed to work with the turbocharger. But if you abuse it, it'll be wrecked. A lot of folks who drive fast cars abuse them.
I will say that _some_ turbocharged cars have a particular issue where the turbocharger remains hot after the engine is shut down, but oil stops circulating through it. As a consequence, it tends to bake the oil into varnish which clogs the turbo bearings up. Idling the car for a little while before shutting it off can reduce the problems, as can using synthetic oil that has a higher breakdown temperature.
--scott
It's the "being driven by hooligans" factor that most strongly reduces the lifespan of engines.
--scott
"Ed Pirrero" wrote
So, why do designers use small turbos, or multiple turbos so that full boost is attained at low rpm (1500 rpm in the new BMW engine, for instance)?
Also, why do turbos have a pop-off valve to limit boost at higher rpms?
Methinks your statement doesn't accommodate those facts.
FloydR
mobil 1 synthetic, even more often than recommeded if you drive hard. Also a good filter, and never forget your Air filter. follow the above and you will get many trouble free miles on your car.
2005 PT GT 2.4. Also most people idle thier cars for a while after a good run. This includes low spped of 30 mph which is sufficient to cool it down. It will last like any other engine. Just a dad, Wayne
The LPT Saabs aren't the only ones they do ! Check out an Aero.
Graham
Only to Americans.
Apparently not.
Graham
100% agreed. Crappy drivers can trash *any* car in fact.
I've never known anyone claim that 300 bhp from 2.3 litres was relatively low performance btw !
Graham
"223rem" said in rec.autos.driving:
Reliability aside, there is another good reason to avoid these types of cars: the Evo is number one on the list of most expensive vehicles to insure.
Eeyore said in rec.autos.driving:
And it does this by recapturing energy that would otherwise have been lost out the tailpipe.
Do A Google Search.
DYKA?
"Floyd Rogers" said in rec.autos.driving:
Because they sound cool?
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