Originally Posted by
D3bb4
Yes well, i've never seen the pistons from these motors - hence i have said so numerous times. 7psi is about average factory setting for alot of older turbo motors. 11-12psi is limit of skylines with ceramic turbine wheels, else they break... but if you say that 15psi is average, go for it.
If you would kindly notice: i did say that the motor will get stuffed if the tune is wrong... but excessive pressure/force on the pistons can also cause failure.... you shall be stressing engine components beyond their designed loads - but these loads would have a safety factor when designed/built, hence why you can alter the engine, and not have these components fail.
Size of turbo: larger turbos flow more air. More air means needs more fuel for same compression/boost compared to a smaller turbo - less flow, less fuel needed, same boost. Is what i was saying.
High compression can cause rings to go, as pressure can force it's way past, or can crack ringlands. You seem to have stated that the ringlands must be rather well spaced and it is not an issue for these motors... ok...
I would *NEVER* base a judgement on the fact that it's a german engineered motor. Not saying that the engineering is bad; but they made the motor to be a 2l n/a motor, not a 300hp turbo motor... and thus if you shove a turbo on and run 300hp... it was not designed for that, as such a design would cost more to build, and thus you are putting stress on engine components that was not meant to be there... so obviously the engine will not last as long, regardless of the tune...
1. do you own a VW?
2. large turbo's only flow more air if they can actually spool up... can you read a turbine efficiency chart?
3. why does my standard diesel mk3 plodder run 14psi standard boost.... and not have reliability issues?
4. higher compression doesnt put more load on the rings/ringlands - higher peak cylinder pressures does.
5. talking of connecting rods.... VAG make a lot of cars, and a lot of engines... infact, more engines than cars, since they sell 'em to a lot of other firms.... this means simplifying construction.... its why for years there were only 4 lenths of rods in all vag engines.... and 1 or 2 bearing sizes..... etc etc etc... the point is, anyone who REALLY knows about german engineering can tell you with confidence that your VW engine is nearly always over engineered to buggery - that you can drive it hard all its life and you wont kill it much faster than if you'd driven it like a granny - and that it makes more economic sense to make 10,000,000,000 diesel spec rods in one plant than build 40 different plants to make 40 different types of rods.
'07 Touareg V6 TDI with air suspension
'98 Mk3 Cabriolet 2.0 8V
'99 A4 Quattro 1.8T
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