What price clean air ?

[totta Crolla]

  stock filter.bmp (Size: 425.3 KB / Downloads: 357)
  perf filter.bmp (Size: 423.99 KB / Downloads: 611)
Here are a couple of logs from a Freedom ecu using the stock inlet air temp and MAP sensors, the difference between the two is the air filter. One uses a foam filter type with internal bell mouth attached to a piece of Samco hosing onto the throttle body. (31.8 air temp)
The other log is the standard AE86 filter. (This log reads 23.2 air temp)
Logs were taken within ten minutes of each other on a fully warmed engine and the outside air temp was the same.
The outside air pressure was 766 mmHg and as can be seen there is a small restriction in the stock air filter compared to the performance one but the cooler, denser air from the stock filter more than makes up for it.