How does the AEM EMS work?
#32
Originally Posted by Scorpion,Oct 18 2006, 11:35 PM
It really depends on the dyno you are using. Best case is you have access to a dyno with load control. The way I do it is I pick a RPM cell, say 3000, then I just hit each cell in the map in the load collum. In each cell add timing until the you don't see any gains in torque and move on to the next cell. Of course this only works for vacuum and low boost states. You wouldn't want to hold the car at 7000rpm at 10psi while you added timing, it'd be alot of stress on both the car and the dyno. For your WOT runs just graph it out, add .5 degrees, graph again and compair them. If you made torque, try it again until you don't. You can use the same technique or vacuum states if you don't have a load-baring dyno. It just takes a little longer.
Be aware that until you are proficiant at it, it will take some time and will cost you some money on the dyno. But once you get it down, it'll go quick. When I attended EFI 101, the instuctor took a blank map and fully tuned a WRX in 45 minutes. One day....I'll be that good
Be aware that until you are proficiant at it, it will take some time and will cost you some money on the dyno. But once you get it down, it'll go quick. When I attended EFI 101, the instuctor took a blank map and fully tuned a WRX in 45 minutes. One day....I'll be that good
#33
I've used load bearing dynos at steady state up to 5000 rpm and 5 psi before. Once you get beyond that, most people use a sweep test. In lower RPM, I add timing in real time and watch the torque reading. For high RPM and high boost, I do a pull, add timing, do another pull and compare torque. If you can graph 4-5 runs at once, it is very easy to see the trends. Start out very conservative and you should be safe. Remember, tune fuel first with SAFE timing and then move on to tuning timing. I ONLY recommend Dyno Dynamics and DynaPack dynos for steady state tuning. Superflow makes a good dyno, but IMO it is not sensitive enough for part throttle steady state tuning.
Tim
Tim
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Originally Posted by timg,Oct 20 2006, 08:56 PM
I've used load bearing dynos at steady state up to 5000 rpm and 5 psi before. Once you get beyond that, most people use a sweep test. In lower RPM, I add timing in real time and watch the torque reading. For high RPM and high boost, I do a pull, add timing, do another pull and compare torque. If you can graph 4-5 runs at once, it is very easy to see the trends. Start out very conservative and you should be safe. Remember, tune fuel first with SAFE timing and then move on to tuning timing. I ONLY recommend Dyno Dynamics and DynaPack dynos for steady state tuning. Superflow makes a good dyno, but IMO it is not sensitive enough for part throttle steady state tuning.
Tim
Tim
Not sure if you have had the opertuity, but I hear Land and Sea makes a really good dyno for steady-state tuning. I think it's called Dynomite. I'll be jumping on one in a month or two, I'll let you know what I think of it.
#35
I actually used a Land and Sea dyno on a snowmobile. It seemed a little bit better than the Super Flow SF901 water brake dyno we were using, but IMO that was due more to size than anything else. I'd be interested to see how their chassis dynos compare. The other one I want to see is Dynojet's eddy current steady state dyno.
Tim
Tim
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It's not necessary to get AEM's UEGO. However, I do suggest having a good, reliable wideband inputting into the AEM EMS while tuning. With the power of the EMS' internal logging, it makes tuning much easier and spot on.
As for automapping, you'll find that most good tuners will never use it.
o2 feedback works well. however, it should not be used as a bandaid for a bad tune. you need to make sure your main fuel map and trims are VERY GOOD first. the purpose of o2 feedback is to more easily accomodate for changes like intake temp, seasonal changes, etc. Of course, these are all things that can be tuned for without using o2 feedback. but most tuners won't take your car for a full year to accomodate for these changes so o2 feedback comes in handy. a failing o2 sensor also shouldn't sway your tuning too much as your main fuel map tune should be good enough that it doesn't heavily rely on o2 feedback (+/- 5% allowance at the most). I never use o2 feedback in boosted areas, only vacuum.
Darryl
As for automapping, you'll find that most good tuners will never use it.
o2 feedback works well. however, it should not be used as a bandaid for a bad tune. you need to make sure your main fuel map and trims are VERY GOOD first. the purpose of o2 feedback is to more easily accomodate for changes like intake temp, seasonal changes, etc. Of course, these are all things that can be tuned for without using o2 feedback. but most tuners won't take your car for a full year to accomodate for these changes so o2 feedback comes in handy. a failing o2 sensor also shouldn't sway your tuning too much as your main fuel map tune should be good enough that it doesn't heavily rely on o2 feedback (+/- 5% allowance at the most). I never use o2 feedback in boosted areas, only vacuum.
Darryl
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Darryl,
At the end of your post you say that you never use O2 feedback in boosted areas, only vacuum. For those of us who don't have a dyno close by, don't you think using O2 feedback under boost might be beneficial? Here in Washington, DC it might be 100 degrees in the summer and -10 in the winter (Fahrenheit obviously). Is the AEM able to cope with those kinds of seasonal changes without O2 feedback? Should I get it tuned by Inline every season?
Thanks for the help!
J
At the end of your post you say that you never use O2 feedback in boosted areas, only vacuum. For those of us who don't have a dyno close by, don't you think using O2 feedback under boost might be beneficial? Here in Washington, DC it might be 100 degrees in the summer and -10 in the winter (Fahrenheit obviously). Is the AEM able to cope with those kinds of seasonal changes without O2 feedback? Should I get it tuned by Inline every season?
Thanks for the help!
J
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I don't feel o2 feedback is quick enough to make changes while under full throttle in boost. If anyone has ever tuned a car with o2 feedback enabled, and a poorly tuned fuel map, you can actually see o2 feedback make it's changes on the wideband. It's just not quick enough for me under WOT.
Dyno or no dyno, your tune must be stable enough before activating o2 feedback. We have temperatures in Toronto just as drastic as yours. So tuning for temperature changes is nothing new to us. AEM is definitely able to cope with drastic changes like that. But o2 feedback honestly isn't the way to do it in my opinion. In a case like that, I use the Air Temp Fuel Correction map/table. So yes, I would suggest having it tuned every major season change. But I'm not talking a full retune. Something like that can be tuned out in as little as 2 full throttle pulls using the Air Temp trim map. And once it's done, you never have to do it again unless you make some modifcations to your engine. This is why I mentioned that no tuner will be willing to take your car for a full year.
Darryl
Dyno or no dyno, your tune must be stable enough before activating o2 feedback. We have temperatures in Toronto just as drastic as yours. So tuning for temperature changes is nothing new to us. AEM is definitely able to cope with drastic changes like that. But o2 feedback honestly isn't the way to do it in my opinion. In a case like that, I use the Air Temp Fuel Correction map/table. So yes, I would suggest having it tuned every major season change. But I'm not talking a full retune. Something like that can be tuned out in as little as 2 full throttle pulls using the Air Temp trim map. And once it's done, you never have to do it again unless you make some modifcations to your engine. This is why I mentioned that no tuner will be willing to take your car for a full year.
Darryl
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Darryl,
Thanks very much. I will take note of this when I go to Inline for my tune. First I'm going to decide which wideband I want to go with (to plug into my EMS).
Best,
J
Thanks very much. I will take note of this when I go to Inline for my tune. First I'm going to decide which wideband I want to go with (to plug into my EMS).
Best,
J