trying to learn more about turbos

[Bimmer_man]

So ive been reading about turbos and from what ive gathered is the Precision PT6266 turbo is a great option for the M30B35. I saw there is a ball bearing option. Whats so special about the ball bearing with turbos?
I was also just looking around and came across variable geometry turbos and that honeywell duel boost turbo. All I see is the VGTs are mainly a diesel option. why?

What im trying to accomplish is something that from what i see is pretty common and thats to reduce turbo lag to almost nonexistent. Can this actually be achieved?

Sorry if these questions seem like noob questions. I know a lot more about High revving NA engines.

[sayed ali]

That's a great turbo, make power, spool fast ..

some of the differences between Ball Bearing and Journal Bearing turbos are that the ball bearing turbos will make more power, spools faster, last longer..

Good luck

[ak-]

Ball bearing turbo's have less friction while spinning internally which has it's pros and are designed differently internally also requiring less oiling than a traditional journal bearing.

Ball bearing turbo's don't necessarily last longer, but are easier to damage, more expensive to replace, and a lot aren't repairable/serviceable - you'll need a completely new CHRA.

VGT's are mostly geared towards diesel engines because it's all about efficiency for these trucks that are hauling huge loads. VGT's turbine side has internal fins that can be manipulated to simulate a smaller Area Ratio (AR) which will provide a faster spool that heavy trucks need when climbing uphill at low speeds. These fins can then open up when they are at "cruise" so that the turbine doesn't spin as fast/choke up exhaust gasses while traveling at speed and create high EGT's when a faster spool isn't needed.
I don't see how a racecar would need a VGT. There are many turbo's out that that can be tailored to the motor and type of driving you are doing.

[Bimmer_man]

Wow thanks for the great information guys. I appreciate it a lot. I'm going to do more reading on turbo systems to better understand everything.
For the m30 from what I've seen the best manifold would be good n tights m30 turbo manifold correct?

Is there any way to retain the ac with a turbo set up?