How important are air temp. ignition/injection corrections?

[Mankee]

My car didn't have an air temp sensor plugged into the Emerald, so it has always run with a default value of 20 degrees C, regardless of if it's the cold winter or blazing summer air. I've got a new air filter setup with an air temp. probe boss welded to it so can finally have live air temp. ignition and injection corrections.

 

My question is how critical are air temp. corrections? I'm unlikely to be tracking the car in air temps much below zero nor above 40 degrees C, seeing as we are in mild England. It doesn't seem to be particularly high resolution as the map uses 10 degree C increments.

 

My ign. corrections currently look like this and my inj. corrections like this.

 

I guess it would be handy having that little bit extra fuel and advance in the winter when the air is more dense? Engine is an internally standard Elise 1.8K (118bhp) with Jenveys and Emerald.

[DohNut]

 

Although the input points are 10 degrees apart the ecu interpoates between them, and as air expands linearly, it is high enough resolution.

Depending on your set-up the air intake temperature could be alot higher than ambient as exhaust and radiator heat up the under bonnet air.

 

N

 

 

[fred_gustafsson]

Just for the fun of it, I put a digital temp sensor inside the plenum chamber on my duratec 175. It's places just downstream of the butterfly and it runs a ten degrees hotter than the air temp when running at speed. When stuck in a traffic jam, it quickly goes up to 30 degrees or higher that outside temp (67 is the highest I've seen).

[Mankee]

Ah, that's a very good point. Silly me assumed that the air intake temp. would be roughly the same as the ambient temp. My car is track-only, so won't spend much time sitting around in traffic and will be on the move most of the time.

 

So my next question; do I need to alter the ign. and inj. correction values in the map and to what?