aem tuning

[napkinthief]

so ive got my aem v2 installed, with map and iat sensors from aem

i got the car steady idle and starting hot and cold. its idling about 14.2-14.5 afr, which i am very happy with. low rpm / light throttle it drivabilty is great. wont stall at lights or slowing down.

im having an issue with low boost application though. ive riched up the fuel map a LOT (2-3x the fuel via IPW at 0psi), but its still spiking out to 16 afr when i hit low 2-3 psi boost. i immediately let off and adjust more in the map and its not doing anything. i also adjusted the boost fuel trim to add up to 100% fuel at 15psi (thinking double atmospheric should need double fuel) and its still going lean.

is there any other place to compensate for boost?


ive seen 2 ways to go about it, flatten out the fuel map after 1psi, then use the boost fuel trim table to increase 100% fuel at 1bar (didnt work how it should) or flatten out boost fuel trim and double the fuel at 1bar then interpolate. i did both ways and both pinned lean. i stopped here and could not find a reason why

[Chris@Rvengeperformance]

the Basemaps boost comp works fine, can you share your calibration and a log showing this? Where is your map sensor and which is it?

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[RealMcCoy]

I'd also rule out a mechanical issue not related to the tune... Are you sure you're getting proper fuel pressure rise with MAP increase?

This is a new install, You did sync the base timing right?

You have the correct injectors selected, and are confident the latency is correct?

A lot of what might appear to be stupid questions... But it saves someone else from having to ask later.

[napkinthief]

i got the tune done at evans tuning in pa

the spike is due to the aem 3.5 map sensor getting turbulence during the 0psi to positive manifold transition

we solve it by creating a restricter, the 1/4" vac hose got cut down to prob a 30 thou hole in a small fitting and it stablized the reading, creating a smooth transition.


tacking on i maxed out the 550s at 400 whp and tq, at 17 psi boost

going back wtih id1000s and some kinda better ignition system

[Chris@Rvengeperformance]

i got the tune done at evans tuning in pa

the spike is due to the aem 3.5 map sensor getting turbulence during the 0psi to positive manifold transition

we solve it by creating a restricter, the 1/4" vac hose got cut down to prob a 30 thou hole in a small fitting and it stablized the reading, creating a smooth transition.


tacking on i maxed out the 550s at 400 whp and tq, at 17 psi boost

going back wtih id1000s and some kinda better ignition system

I'm very interested in this. Do you have a log of the problem area? I currently have the map sensor directly screwed in to the intake and I have some very weird fueling needs in my map at 2700-2900 and -5 to -8 PSI load. I can't seem to completely eliminate a hesitation there.

The map signal doesn't look that shaky to me though.

There is a software smoothing option to a number of wheel teeth for the map signal FYI, I would think this would have a similar effect as the restrictor. If you go to the sensors tab, then map sensor options there is a map filter which the basemap has set to 3 teeth. Setting higher may smooth the signal, but too high will make transient fueling incorrect. Too much accel fuel would likely be required.

[napkinthief]

I'm very interested in this. Do you have a log of the problem area? I currently have the map sensor directly screwed in to the intake and I have some very weird fueling needs in my map at 2700-2900 and -5 to -8 PSI load. I can't seem to completely eliminate a hesitation there.

The map signal doesn't look that shaky to me though.

There is a software smoothing option to a number of wheel teeth for the map signal FYI, I would think this would have a similar effect as the restrictor. If you go to the sensors tab, then map sensor options there is a map filter which the basemap has set to 3 teeth. Setting higher may smooth the signal, but too high will make transient fueling incorrect. Too much accel fuel would likely be required.

i mean it couldnt hurt to try. i could snap a pic for you later today. its a very very simple and crude device. get a plastic T. melt one side closed. melt another side almost closed. connect to the map and notice any change.

[Chris@Rvengeperformance]

i mean it couldnt hurt to try. i could snap a pic for you later today. its a very very simple and crude device. get a plastic T. melt one side closed. melt another side almost closed. connect to the map and notice any change.

I appreciate the info, I was mainly interested in seeing what the before and after aem logs look like.

Thanks

[napkinthief]

ill try to pull the logs off the aem and see if its still on there... gladly share if i have em. if he was logging to his laptop though, i wouldnt have them will let you know