AEM Safety features

[turbogate]

Besides setting the AEM to retard timing when it sees knock which requires logging and setting up a base knock to eliminate noise. What are other good safety features one should enable with the AEM? For example, at what AIT temperature should I have the AEM do something about it? at what water temperature should I have the AEM do the same?

In other words, what's considered dangerously high coolant temperature, and what air intake temperature is considered to high? Am I missing other safety features that the AEM offers besides boost cut etc?

Thanks

 

[turbo joe]

Generally .02 would be that regarding the air temp...it's not really a "safety" feature in my book. It's more a VE thing. Hot air is less dense and you need less fuel...but not all that much less.

I generally don't subtract much at all with regard to air temp. Think of it this way...with the air getting progressively hotter...if you leave that function relatively flat or zeroed out, it would make the mixture relatively richer as the charge temp climbs.

I'm not sure what you would really want an ECU to do as a "safety feature" with regards to water or air temps, aside from commanding the fans on or lighting a big lamp to tell you to slow down.

I'm generally not a big fan of having an ECU try to save the day...all the possible/common remedies (more fuel or less spark) have their own consequences and they really can't do anything to effectively change the situation. In a lot of cases you're just forestalling the inevitable and running up the tab in terms of damage. I'd rather have a light go on or a big hiccup tell me it went off the tracks than keep on driving with the ECU progressively dumping more and more fuel and retarding the timing more and more.

 

[p5150]

I just typed a bunch of garbage and realized that I didnt even reply to your post. Here goes what I hope to be a legitimate input:

Did you see the section in the AEM manual about richening the fuel mixture if the engine starts to get too hot? I think you can use the same table as used for the cold start function to richen the fuel and cool the engine if it gets warm.

 

[turbogate]

Thanks for the replies. I was thinking about mimicking some basic safety features that the stock ecu does. For example, I read on here that the stock ecu starts pulling timing when coolant temps reach 210F. I guess it will only make a difference when I start using a more aggresive timing map. It's pretty conservative right now.

Thanks again

 

[John Reed]

A bit of timing retard and fuel addition as an engine gets too warm is fine, but be careful of too much retard as it will simply drive your EGT's (on an already hot engine) even higher. It is all a bit irrelevant actually, as I don't recommend running an engine for long periods outside its normal temperature range.

For air temp, I typically do put some retard in (depending on application) at certain air temps to cope with both the higher air temps and higher cylinder temps as you do a long run. I set this up on a case by case basis. Trimming fuel by air temp is tricky, it is a balance of keeping things cool and not going too rich (on a race car where performance is put before longevity for instance). Again, tune it for your use and comfort level.

One of the best little features on the AEM is using the check engine light as a "lean warning under boost" light. This is one of my customers favorite options and comes in pretty handy. Set the boost and air/fuel thresholds and then you have something to catch your attention. Of course if you spin the tires or your turbo outspools your lambda sensor feedback rate you may see a flicker but still works excellent.

Knock control on the AEM is excellent, but as someone else stated the ECU should not be expected to save us from anything stupid we try and do. But it is very good at making on the fly tweaks due to changing conditions (including the knock control helping you out if you get a crap tank of gas or something).

Hope that helps guys!

 

[tissimo]

One of the best little features on the AEM is using the check engine light as a "lean warning under boost" light. This is one of my customers favorite options and comes in pretty handy. Set the boost and air/fuel thresholds and then you have something to catch your attention. Of course if you spin the tires or your turbo outspools your lambda sensor feedback rate you may see a flicker but still works excellent.

word, love that feature. you can setup all kinds of warning lights if you so wanted (and to mount in you cluster/line of sight)


another thing you could do..
use the outputs to turn off a relay powerinng your boost controller (or just the solenoid) if settings arn't right (a/f, temp, etc)..