If you could read a compressor map you'd see that at 7 psig manifold pressure a stock t28 can efficiently and adequatly provide mass/volumetric flow to keep up with a 2.0 liter engine to 7,000 + rpm. Your assumption only holds true when the volumetric/mass flow rate demand (calculated as a function of engine speed, displacement, manifold pressure and intake air temp.) exceeds the cabaility of the t28 compressor. This happens around 12-14 psi when comparing a t28 to a 2871. So, yes 14 psig with a t28 is not the same as 14 psig with a 2871. But, a t28 and a 2871 will provide approximatly equal mass/volumetric flow rates until redline when the flow rate demanded of the compressor is only enough to maitain 7psig of manifold pressure on a 2 liter engine.
Additionally, I personally ran a 2871 on stock injectors and maf for about 6 months. From memory, at the stock wastegate setting the injector duty cycle barely ever got over 80% and the stock maf never read over 4 volts (as measured with a powerfc).
So, as you can clearly see, the stock fuel system is completely adaquate to handle ANY sized turbo/supercharger capable of maintaining 7 psig manifold pressure up to 7,000 rpm with reasonable intake air temperatures (ie. not -40 F or anything of the likes). It however could not keep up at say 10,000rpm (if the engine could spin that fast) or if the engine was larger than 2.0 liters.
Quote:
Originally Posted by jspaeth
Yeah, that makes SENSE! 
Please do not give out information that is wrong, unless you want to send this guy $3000 for a motor rebuild when his engine blows.
Two different turbos do NOT (necessarily) put out the same mass air flow at the same psi.
The S14 SR T28 turbo does not flow the same air at 7 psi as a GT2871R at 7 psi, so please do not tell people that. |