Originally Posted by
LeonOfTheDead
The correct stoichiometric ratio (which isn't the one provided by chemistry as a combustion chamber isn't the perfect and ideal volume on which those reactions should take place) can be maintained even by a naturally aspirated engine.
Each cylinder would divide the quantity of air that just entered, divide it per 14,8 (iirc) and introduce that quantity of fuel. This is done by both engines, just the turbocharged engine can "contain" much more air, thanks to the turbine, and accordingly, it will enter more fuel, but still 1/14,8 times the quantity of air in the cylinder. Actually, as I mentioned, engines don't work at the stoichiometric ratio, as that's the theoretical value for having the perfect combustion, which never happens. So a lean or rich mixture of air and fuel is to be adopted, also to help to cut the emissions on the exhaust line.
But this is a different story, still, the stoichiometric ratio has nothing to do with the turbocharging. It just changes the quantities, not the ratio.
That's my point, so there s no reason to think the SHO's engine won't work properly
That's not physics, it's statistics.
By that, everything could fall apart, but there are things so common that they are now considerable as a safe and reliable component. Even a connectin rod could collapse under the stress of the combustion cycle, but it doesn't happen, because it's a common component and there aren't secrets about its design. So it's for turbos. The can fail, that's why warranty exists, but statistically they won't.
Superchargers used to be a bit less reliable, especially the scroll ones, but they are fine since quite some time now.
I mentioned Tata only for as regards who owns Jag, don't say I meant it to have an engineering meaning.
How are Lexus'? Cars full of stuff, especially the hybrid ones. Mercedes', BMWs? All the same. Are they reliable? Yes. they are also more expensive, that's for sure.
The I6 twin turbo from BMW is available also on the 1 Series coupe, which should have (I think) an after all similar price in the States as that of the SHO.
The BMW's is a good engine, and reliable. I can't see a given reason for the SHO's to be different.
As I said above, turbos are a common element, designed and redesigned for years, I'd say they know how to build them by now. Also, we are not talking about a 300 bhp/liter engine, it's a 100 bhp/liter one, a pretty common and "safe" value for a turbocharged engine.