is 1bar of boost from stock turbos *exactly* the same as 1bar of boost from a pair of twin T78 or some other mammoth setup? Or does one have to factor in turbo type when comparing boost levels from car to car?
If you have small turbine housings, you will have more pressure in the exhaust manifold, which will require more mechanical effort from the crank to expel the ex. gas = lower crank hp.The only difference is that bigger turbo's can deliver the 1 bar more efficiently and so delivering 1 bar of cooler air. And can make a little bit more power. I don't know how efficient the stock turbo's are @ 1bar but the difference wouldn't be too big at that pressure.
When the manifold is filled with 1 bar off pressure it shouldn't matter which turbo deliverd that pressure, but how effiecient the turbo(s) deliverd that pressure. The efficiency of the turbo makes the charge temperature hotter or less hot.
If you improve the inlet chanel, like piping, filters, and do a port job youb can make more power with the same boost pressure. That's because more air actualy gets into the cilinders.
so in essence, the volume of air moving from turbos to intake is the main factor, not the pressure of the air itself. And a bigger pressure differential between the exhaust manifold and intake will result in more air volume flow at a given pressure? ah, I feel more enlightenedIt is all about volume flow, for the same pressure a larger turbo will flow more air.
The restriction in the intake chanel, and the volume efficiency of the engine, and the engine RPM determine the volume flow of air trough the intake chanel.It is all about volume flow, for the same pressure a larger turbo will flow more air.
therefore, when Skyline owners talk about how much boost they're running, it can't really be comparative unless both cars have the same turbos, similar intakes, etc?
Its mainly turbos, and head/cam spec. If they wildly different then its a pointless comparison.therefore, when Skyline owners talk about how much boost they're running, it can't really be comparative unless both cars have the same turbos, similar intakes, etc?