I've seen a few threads recently about the warmer temperatures affecting their tune (whether it be SC / turbo, doesn't matter). Now I know "good" tuners use the map sensor to tune (engine load for the AEM EMS) so the tune is slightly affected by temps however, I was curious if there was some way to integrate an actual ambient air temperature thermometer into these tuning units to add another (possibly very important) parameter that could really help with these issues that some people are having.

How do the stock ECUs compensate for temps? Do they really just "listen" for knock, adjust accordingly, and also go with TPS / MAP sensor?

 

The ecu uses the iat and water temp sensors. The iat has the biggest effect. The ecu does listen to det, but turbos usually make the sensor useless. The ecu uses the iat, map, and tps sensors to calculate density and intake. The added heat had unseen consequences due to most of us being tuned in cooler weather. I don't think any of us running the emu expected such a drastic change. The. Stock ecu goes nuts in the heat and adds a ton of fuel. It can be tuned out, but was just unexpected. The ambient temp isn't as important as the iat because that's what the ecu uses for the final calculation. I'm not sure what's going on with the timing either, but the ecu is definitely adjusting it quite a bit. I need more free time to get some good logs.

I think a lot of us are on the edge of our cooling systems too. The heat doesn't help.

 

The AEM EMS gives complete control over the IAT and ECT calibrations. If the tune is correct, it should be pretty close all of the time. Closed loop control can also help rein things in.

Tim

 

Can't wait to install mine.

 

So then this seems to be more of a Greddy emanage blue / ultimate problem? (I don't think you can control based off that, atleast I know in the blue you can't).

Maybe we can add this as another reason why the AEM EMS great