Quote:
Originally Posted by Rom3n
The last time we measured AIT's here in Phoenix we did so with a stock car, the VT1-535 and the VT2-600. Ambient temp during dyno testing was 90F. The stock motor had an AIT around 110F due to radiant engine heat, the VT1-535 was close to 160F while the VT2-600 was around 130F. The threshold when you will no longer make power with further increased boost is usually about 220F or ~8PSI boost in most applications.
Heat will affect all FI applications even those that have cooling systems. Many factors will affect AIT's. Factors such as air intake placement, radiant engine heat, IC cooling efficiency and airflow. You can still have high AIT's on a intercooled FI application if you run high enough boost or the cooling efficiency of the intercooler is low. We have tested chip tuned SL65 AMG Mercedes with OEM air/water cooling that run AIT's in the 240's in 90 deg F so simply running a cooling system does not always guarantee you low AIT's. A Stock Bentley Speed W12T we tested recently in 95F returned IAT's in the 180F range.
For every 10 deg F in temp you raise IAT you will loose about 1% in power output as the air is less dense. The immediate advantage of a supercharger kit running a cooling system is that it will make more power. The amount of power will be determined by the efficiency of the cooling system. For example
the 7% increase in power between the VT1-535 and VT2-575 is provided by the 1 psi increase in boost pressure and the lower air intake temperature provided by the air / water cooling system. The difference between the VT2-575 and VT2-600 is 4% due to the fact that they are using the same cooling and are only seperated by the addition of 1 psi of boost pressure.
It is very common for many factory and aftermarket supercharger systems to run without cooling, especially low boost applications. The VT1-535 is very conservative in both boost and tune paramters, and it is fully tested for heavy track duty.
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Thanks for the great information as always.
Have you monitored the effect of VT1 and VT2 kits on exhaust gas temperatures on the track?