AEM Engine Management System (Q & A)
#63
Update: We got the EMS tuned and put down 265whp on our mustang dyno ~9psi. I love this system. My tuners said the tuning wasn't hard but the setup is more difficult. We still have problems with cold start and it takes about 3-4 cranks to start the car, also my coolant temp gauge on the cluster is not working properly. Anyone else having this problem?
I'd like to thank Sean@torquefreaks for putting up with my questions and bothersome calls but in the end it was worth it. Also much appreciation goes to this board and especially to this thread for all the good info. More power to you guys.
I'd like to thank Sean@torquefreaks for putting up with my questions and bothersome calls but in the end it was worth it. Also much appreciation goes to this board and especially to this thread for all the good info. More power to you guys.
#64
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[QUOTE]Originally posted by KYS2000
We still have problems with cold start and it takes about 3-4 cranks to start the car, also my coolant temp gauge on the cluster is not working properly. Anyone else having this problem?
Yes I have the same problem cold starts and the gauge cluster not working properly!!! Always at 1 bar. ~nate
We still have problems with cold start and it takes about 3-4 cranks to start the car, also my coolant temp gauge on the cluster is not working properly. Anyone else having this problem?
Yes I have the same problem cold starts and the gauge cluster not working properly!!! Always at 1 bar. ~nate
#65
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I've read that the AEM EMS doesn't support the temperature gauge on the S2000 dash because the gauge looks for a coded serial data stream that the Honda EMS can provide but the AEM EMS can't (or, more precisely, doesn't). I don't have that problem as I don't have an S2000 dash, but I did find that the AEM calibration for the air inlet temperature sender (AIT) did not match the sender on my S2000 engine and I needed to recalibrate. That helped the cold starting issue, though fussing with the Start Fuel parameters could have the same effect. I now get a cold start after about 2 seconds of cranking. I have more difficulty with hot starting, sometimes taking 4 or 5 seconds -- sometimes not. Hmm.
#66
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[QUOTE]Originally posted by hans
I've read that the AEM EMS doesn't support the temperature gauge on the S2000 dash because the gauge looks for a coded serial data stream that the Honda EMS can provide but the AEM EMS can't (or, more precisely, doesn't).
I've read that the AEM EMS doesn't support the temperature gauge on the S2000 dash because the gauge looks for a coded serial data stream that the Honda EMS can provide but the AEM EMS can't (or, more precisely, doesn't).
#69
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If anyone is interested in checking out my map for an AEM ECU running an NA S2000 engine (not in a Honda automobile), it's now in shape where it can be shared. The fuel table is good enough that the engine runs well in closed loop with an AEM UEGO targetting 14.7:1 @ low load going to 13:1 @ WOT/no boost, very rarely hitting the +/-10% correction limits. The car starts and idles well in all conditions that I've seen so far in northern California and has good throttle response. I'd appreciate seeing maps that others have found to work well, especially for road racing.
Unfortunately, I don't have a web site and don't know how to attach a data file to this post, so I need some help here.
Unfortunately, I don't have a web site and don't know how to attach a data file to this post, so I need some help here.
#70
It's true that with the EMS, the stock temperature "gauge" (bar-graph?) won't work -- but mine's never jumped to all bars under any conditions, so I'm not sure what that's about. Also, the temperature gauge table provided with the stock S2K map isn't correct -- several of us have discovered this when datalogging on the track.
Sean's got a table that Giles put together based on actual empirical measurements -- which he compiled using a kitchen thermometer. It's not perfect (his data points don't run into the dangerously high zone so he had to extrapolate using fancier math than I can describe to fit the points to a curve), but it's better than the version that comes with the EMS.
I can't speak for the low range readings (they aren't really important, provided you can get your car to start on cold days), but I do think the higher ranges are more accurate. The general experience has been that the EMS reports higher operating temps by 10-15 F degrees or so.
Unfortuanately, nobody's been able to find a Honda table to relate stock temperature voltages to the stock ECU temperature readings to the "bar" temperature display on the dash, so it's really hard to draw any solid conclusions from all this. That's one of several reasons, we intend to mount a separate temp. gauge and wire it into the EMS.
CB
Sean's got a table that Giles put together based on actual empirical measurements -- which he compiled using a kitchen thermometer. It's not perfect (his data points don't run into the dangerously high zone so he had to extrapolate using fancier math than I can describe to fit the points to a curve), but it's better than the version that comes with the EMS.
I can't speak for the low range readings (they aren't really important, provided you can get your car to start on cold days), but I do think the higher ranges are more accurate. The general experience has been that the EMS reports higher operating temps by 10-15 F degrees or so.
Unfortuanately, nobody's been able to find a Honda table to relate stock temperature voltages to the stock ECU temperature readings to the "bar" temperature display on the dash, so it's really hard to draw any solid conclusions from all this. That's one of several reasons, we intend to mount a separate temp. gauge and wire it into the EMS.
CB