Are new turbo engines less peaky?

I really don't know about that, but the very nature of turbochargers is that they don't become really effective until they reach higher rpms - like you said beyond 2500 rpm

The engine has very low torque at low RPM

that's complete bullshit the torque curve on my 1.8T A4 is as flat as ohio beyond 1800 rpm.

I'm looking at the torque curve of the 3.0 6 pot engine in the very same car that for some reason is an all american favorite and the picture of that naturally breathing engine is not so rosy in comparison

I used to live there, born in Cincinnati (where the Ohio River gets nearly as low as it ever does along the southern Ohio border). Ohio ain't flat, but it tries to be, thanks to glaciation eons ago. The glaciers stopped near the southern border, where there are some significant hills. Cincinnati is a fairly hilly city.

From :

"Just 1,095 feet separate the highest and lowest points of Ohio, making it one of the flattest states.

"Only seven states - Florida, Delaware, Louisiana, Mississippi, Rhode Island, Indiana and Illinois - have a smaller difference.

"The highest point in Ohio is 1,550 feet, at Campbell Hill in Logan County, U.S. Geological Survey records show. The lowest point of 455 feet is at the Ohio River in Hamilton County."

David

engine has very low torque at low RPM

Somehow that 1.8T does generate decent torque down low. I test drove a GTI 1.8T before buying the '02 wrx and was impressed with that aspect of it at least. The wrx really lights up above about 4000 rpm.

If I reckon correctly that was the reason people were bitching about low displacement and subaru pushed 2.5 liter turbo to the american market.

wrx has other things going for it in snowbelt, obviously ;) I think GTI does not even have an option of a limited slip diff

I rarely venture above 4000 due to horrendous unrefined noise of 4pot engines. opposite or inline -> does not matter. Hence I ponder the usability subaru turbo in my (old fart) case. Truth is, 4s don't sound all that good and poor sound insulation does not help. And obamafication of CAFE fuel sippage limits adds insult to the injury. Add decent sound insulation to combat piss poor 4 pot engine sounds and all of a sudden you have so much poundage that you could just as well put an 8 pot engine to lug that around. And once you put an 8 pot engine in you don't need all that sound insulation cause it sounds good.

Say hello to an imaginary H-8 ;-)

For years, turbos have been peaky, it's the nature of the beast. They've done some things to reduce the peakiness, like use two smaller twin turbos instead of one large one. But still it's a matter of personal preference how one would find it. For example, I would've said getting the turbo kick in at only 2500 RPM is a pretty good low RPM. Superchargers on the other hand have no lag whatsoever.

Yousuf Khan

Thanks Yousef, I knew I was right. I've had a 1985 4WDTurbo that wouldn't really get started until around 3000 RPM. Superchargers have the boost the entire range, but turbochargers - especially the older ones - get the boost only at the higher RPMs. It *is* the nature of the beast.

Modern turbos have automatically adjusted guide vanes that widens the effective rmp range a lot.

That would explain what AD said. I know the older ones were kind of biased toward the high end.

If you want an engine with bottom end torque, you want an engine that eats lots of air at low speeds. That takes either large sisplacement or a positive displacement supercharger.

A turbo engine does not develop any boost untill there is a good hot exhaust, because it is the heat energy in the exhaust that spools up the turbo. Dragsters running turbos sometimes enhance the exhaust with a pre-turbo injector to spool the turbo up ahead of the big event. Not too practical for a more benign street machine.

The advent of variable valve timing HAS fattened up the torque curve - on both normally aspirated and turbocharged engines - so today's turbos at least have the possibility of being less peaky than earlier turbos.