Can someone tell me the concrete benefits of a fast-acting IAT?

Besides "it acts faster."

If I change from my stock sensor to an Apexi sensor with my Power FC, do I have to change any settings besides the IAT sensor type?

Or am I thinking of their pressure sensor...

 

I may have been mistaken. It seems like Apex'i actually uses the FD's stock IAT sensor for all the other cars that originally used MAF sensor-based computers.

 

hopefully this thread will be more informative than whatever i can ramble off lol

https://www.rx7club.com/3rd-generati...sensor-882534/

when installing the sensor, its a direct swap. you dont have to adjust anything. you can either wire it in or use the plug and play adapter harness that some places sell. the reason i got one was so that i can be more confident in knowing my air temps. before i get into boost, i run through a mental checklist to make sure all my parameters are safe to do so. having a high ait keeps me out of positive pressure excitation..... if you know what i mean =D

 

In my experience, if you change the sensor you need to retune your IAT compensation table. The slower response is sort of "baked in" to the table.

 

I swapped mine for a fast reacting one. I don't think it makes much difference when driving around but it really helps with heatsoak idle quality.

My car and my other rotary, an RX-8, had an idle that would hunt after stopping at a petrol station for 10-15 minutes to fill up and let the engine bay bake during that time. If you turned the car back on after heatsoaking the idle would hunt for a couple of minutes and the only way to cure it was to drive for 2-3 minutes above 30 mph or so. to get some fresh air under the hood.

With the fast reacting IAT the hunting lasts for about 10 seconds and then the idle adjusts and smooths out because the IAT has updated the ECU much quicker.