iaps and aps questions

[aaronxs400]

ok so the way i understand it is the ECU reads the ambient air pressure through the APS located in the frame, and the Inlet air pressure through the IAPS which has vacuum lines running to the 4 throttle bodies.

it reads these two sensors and does a calculation and does something to alter the fuel, correct?

i have heard the IAPS is only used for below 10% throttle for idling and low speed stuff.

does anyone know what the value ranges are for these two sensors?

the way i understand it is they are potentiometers that run off of pressure, is that correct?

thanks a million guys.

 

[Commuta_Busa]

you've got it all correct. I don't have a algorithm with me but based on the two pressure readings and rpm determines the fuel mapping below 10% tps. This is for any speed. As for the sensors range, it's easy enough to measure the 0-5v output by attaching an accurate vacum pump to the sensor and write down the measurements.

What are you trying to do? If you need the sensor information I can post it next week.

 

[aaronxs400]

well i found out alot just by looking at the manual.

guys who have the same engine set up as me (EFI, no air box, sidewinder pipe) are hacking the ECU's and running fixed values for the IAT, IAPS, and APS. apparently it makes the bike significantly more consistent in the 1/4 mile.

instead of hacking the ECU i was just going to wire in a resister for the IAT (pry set it at 75 degrees)

and somehow reduce the voltage so the ECU sees 760mmHg for the APS and slightly under that for the IAPS. I hear that at WOT the pressure at the IAPS is slightly under the normal atmospheric pressure of 760mmHg.

 

[aaronxs400]

O and if you do happen to have a chart or something for the sensors ranges that would be awesome.