So basically I've been having problems with climate changes and my AFRs swinging. I made a thread a couple months ago and ever since then I've been playing with these tables in the AEM software (AEMPro) is there a 'one size fits all' template that works in all temperatures or is it engine specific?

A couple questions I have is, for an AP1, what is considered "air intake temperature" is it actually measured inside the manifold? Or should it be measuring the actual outside air temps? It seems that the temperature measured swings a good bit depending on whether my car is moving or not, (increases while sitting etc.)

The problem is with the tables that come with the software, and even with some of the tables I've found on s2ki, if I tune the fuel for say 60*F, and keep all the compensation tables how theyre 'supposed' to be, if the temperature swings +/- 20* I start noticing AFRs getting off from what theyre supposed to be. Too lean in the cold and Too rich in the hot.

I'd like to just hear some expert opinions on the situation, I've been trying to adjust the fuel comp and make the air temp tables reflect what is going on outside, and it doesn't seem to be working.

Also I'm a little tired, so sorry if this post is a somewhat redundant / nonsensical lol

 

I would like help in this area as well.

 

Send me an e-mail/PM. I have a couple of spreadsheets that will do it. One I made, the other is from the internet. They're both quite similar in that they deal with the theoretical correction. Location of the IAT, speed of the IAT sensor, engine rpm, and heat soak can affect the validity of these tables. You won't be able to get it perfect under all conditions, but you should be able to get it correct at steady loads relatively easily.

Tim

 

Anyway you can post the files here?

 

I tried that first, but this forum does not like Excel files as attachments. If there is another way, I can definitely post them.

Tim

 

Air intake temp is measuring the temp in the intake manifold.

To work out your temp corrections you should look into how air density changes relevent to temperature and then convert into a percentage change which you can use in you correction tables.

http://en.wikipedia.org/wiki/Density_of_air

As we can see in the table shown on the wikipedia page above the change in density from +10 to +20 (celcius) is 1.2466kg/m^3 to 1.2041kg/m^3. so that gives a 3.5% decrease in density which means the fueling correction from 10 to 20 degrees celcius would be -3.5%.
The relationship between temp and air density is non-linear though so make sure you work out the correction for each temp listed in your table.

Dan

 

what worked for me is input new water and intake temp tables for those sensors first. then tweak the offset table for intake air. contrary to popular belief, add fuel above 158 degree intake temps. it helped a lot for me when car was sitting in traffic getting heat soaked. tweak break points. choose your max boost you will ever run, and a bit higher then the max rpm yuo would run and let aem rescale the map for that. then fix all the tuning in that, as it will get royally screwed up when you do this.

tune car part throttle driving it around. smooth transitions from one cell to the next helps a lot.



then use o2 fb to trim out since it will never be perfect. mine always hits my target afrs now. just takes time to get it all squared away. a load bearing dyno really helps with this. but i am cheap, so i rented my friend to drive the car for pizza.

 

^^ I like the idea of adding fuel at 160*. I didn't ever like the idea of subtracting fuel from the map, reason for this is because with my cold air intake, in stop and go traffic, my IATs will rise and the map may be subtracting 3% fuel, then once I get going ill be sucking in cold air, the tables don't react fast enough and all a sudden I'm looking at 15.5+ AFRs on medium loads.

What seems to be working with me is tune the car at a temperature, and keep fuel correction at zero +/- 20* from that point, then add fuel at about 1.5% per 10 degrees I think but then I flattened the hot temps at about -1% so it won't ever pull more than 1%. This may need some tweaking in the summer, but for now in 30-80* ambient temps its working great

 

Check the map I sent you. It includes the correction tables paired with the correct sensor calibrations and the same sort of high temperature richening that camuman mentioned. When you get everything sorted out, the car will run very well.

Tim

 

I doubt Timg remembers. But when I first got into the game I asked him for a map and he tought me the ways and pointed me in the right direction but didn't give me a map. He must be getting old. I keed I keed. Trust the guy he knows his shit.