With regard to how much timing is pulled dependant on IAT, here is the stock table for your reference (timing due to IAT is only pulled in conditions above 40kPa MAP pressure (mid-high load)):


Temp (Celcius)30 42 62 92 120
Retard (Deg) 0.0 0.0 4.0 8.0 8.0

So once you're over 42 celcius timing starts to be retarded (in stock form).


Dan

 

Which "stock" table is that? From what system?

 

Its from the stock f20c flashpro map.

 

Good info, thought the stock ECU was around 45c nevermind.

When logging the IAT sensor values with an OBD logger (scan rate around 500ms IIRC i maybe wrong) the sensor seems to react pretty damn quick (dropping in temperature consistent in a dyno room which monitors room temp) unfortunately i cannot comment on how 'far behind' it is in real terms - my knowledge doesn't reach that far.

The information seems sounds, but there's some excellent marketing out there too .

 

Great thread, I also noticed the slow response and heat soak issue with the OEM sensor. I'm putting an AEM one at the end of my aftercooler in a few days.

 

Bumping this thread for 1SlowSi because I'm too lazy to PM him.

 

Lol. This is definitely great info. I am going to stick with its stock location because it has been fine so far. I don't see there being an issue so long as I'm tuning to the same IAT on every pull and some occasional pulls on the street. I don't road race or track race at the moments so I'm not concerned with the heat soak issue. Actually , I disabled the WOT IAT comp tables (ill make changes when necessary) with the exception of the IGN comps because the IAT would have to be pretty freakin high to start retarding timing. If I needed a setup to make rapid changes on the fly for racing then sure, I would look into this. Don't judge me.

 

The whole point of the IAT comps are so you don't (necessarily) have to have a summer and a winter tune. For a moderate climate like Cali, you might be able to get away with leaving it disabled. However, I'm in a pretty moderate climate too and I can tell the difference between driving the car early in the morning or late at night compared to the heat of midday. A/F's are never where I would like them and the car runs richer than I like. It's hard to tune correctly if the IAT sensor is always heatsoaked sitting in that aluminum oven.

 

I can understand that. I do the things the hard way I guess because in the east coast I still fine tuned it for the extreme weather changes. So is the point of this thread stating that the stock IAT is slow and the location is inaccurate with heat soak or just that it's slow in being able to make those rapid changes needed for racing? If heat soak is the issue, then in theory the stock IAT location should definitely work in the winter time minus the fact that it may be slow. Am I right?

 

Both.

No. You can still heat soak no matter what the temp is. That's like saying since its 40* out I can pop the hood and touch the turbo manifold without getting burned. Sure it may not be as extreme, but the issue is still there.