Guest |99| Posted December 17, 2008 Report Share Posted December 17, 2008 I have a general question on setting up the IAT table for turbo engines. During tuning on a 20C day the IAT to the engine will generally rise for increase turbo pressures. Would it be correct to set the '0' compensation at the measured IAT in the manifold after the intercooler for the given boost pressure. If so, then the '0' compensation would be at a different temperature for each boost pressure rather than have '0' compensation at the ambient 20C. Would the remaining compensation values would then be calculated for the temperatures above and below the '0' values.??? Quote Link to comment Share on other sites More sharing options...
rayhall Posted December 18, 2008 Report Share Posted December 18, 2008 The air temp connection table should have 0 in the temperature table at the air temperature of the dyno room when tuned. The ECU then makes the correction based on the air temperature read by the sensor after the intercooler. If the table is setup correctly the air fuel ratio will be corrected as the air temperature of the day changes, no matter how much heat is created by the turbocharger boost. Ray. Quote Link to comment Share on other sites More sharing options...
Guest |99| Posted December 23, 2008 Report Share Posted December 23, 2008 Hi Ray, If the 0 values are set at the ambient dyno temperature (20C) does that mean that the IAT correction has to be set "ON" with the IAT corrections already determined (as below)? If the IAT is "off" during the base fuel table determination and there is "0" in the 20C column and say (-12% @ 60C) then when the engine is operating with the IAT "ON" and the IAT is 60C (nominal) after the intercooler won't the engine run leaner even though the ambient temperature will still be 20C? My typical IAT corrections would be: 0 @ 20C, -7% at 40C, -12% @ 60C, and -22% @ 100C. Quote Link to comment Share on other sites More sharing options...
rayhall Posted December 23, 2008 Report Share Posted December 23, 2008 Chris, Either you are or are not using air temp correction. You do not tune with this disabled then enable later. The values in the table give a fuel correction shape based on the temperature read by the sensor. When you start the car and the ambient temperature and engine is 20 deg, then the fuel correction will be zero. As the air temperature increases with engine temperature or boost, the fuel will be corrected by value in the table. The recommended temperature for zero in this table is 20 deg. The default values are good and should not need changing. Ray. Quote Link to comment Share on other sites More sharing options...
Guest |99| Posted December 23, 2008 Report Share Posted December 23, 2008 Thanks Ray, So basically, initial tune should be with the IAT "ON" and using the default values. Have you had any further updates on when the water proof units will be available? Merry Christmas. Quote Link to comment Share on other sites More sharing options...
rayhall Posted December 23, 2008 Report Share Posted December 23, 2008 So basically, initial tune should be with the IAT "ON" and using the default values. Yes. Marine V44 and V88 have been available for a month or more. Ray. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.