AEM EMS tuning question
Thread Starter
Trial User
Joined: Mar 2000
Posts: 4,264
Likes: 1
From: Jasma
AEM EMS tuning question
Background:
B18 + Toda C
AEM EMS
RC 370cc injectors
Techedge WB 02 sensor, not connected to EMS.
Problem:
The car gets tuned on the dyno, no problem. The A/F ratio is very close between the dyno's WB and my WB readout ~13.5 throughout. This was done on two different dynos.
Once on a racetrack (road racing) the readings while on track show ~11.5-12.5 A/F. Is the meter off? Is the EMS richening the fuel for some strange reason?
The EMS runs on open loop, so it should only be reading the load and rpm, both of which shouldn't change between the dyno run and the track.
Any guesses as to why the reading is that much richer?
Thanks in advance.
B18 + Toda C
AEM EMS
RC 370cc injectors
Techedge WB 02 sensor, not connected to EMS.
Problem:
The car gets tuned on the dyno, no problem. The A/F ratio is very close between the dyno's WB and my WB readout ~13.5 throughout. This was done on two different dynos.
Once on a racetrack (road racing) the readings while on track show ~11.5-12.5 A/F. Is the meter off? Is the EMS richening the fuel for some strange reason?
The EMS runs on open loop, so it should only be reading the load and rpm, both of which shouldn't change between the dyno run and the track.
Any guesses as to why the reading is that much richer?
Thanks in advance.
Joined: Apr 2004
Posts: 78
Likes: 0
From: kissimmee, fl, us
Re: AEM EMS tuning question (El Pollo Diablo)
It could be one of the secondary fuel corrections.... based on intake air temp and coolant temp. Do you have the knock sensor connected and active? If so the tuner may have enabled knock control and when doing this you can set the threshold above which will be considered knock and have the ems pull timing and/or add fuel. And depending on how he/ she 
arrived at the number to consider knock, it may or may not be actual knock but instead just background noise that wasn't present on the dyno but might be on the road course.
Hope this made sense... I am on my way out the door, so this was quick, if you need me to go into more detail I can later.
arrived at the number to consider knock, it may or may not be actual knock but instead just background noise that wasn't present on the dyno but might be on the road course.Hope this made sense... I am on my way out the door, so this was quick, if you need me to go into more detail I can later.
Joined: Apr 2004
Posts: 78
Likes: 0
From: kissimmee, fl, us
Re: AEM EMS tuning question (El Pollo Diablo)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by El Pollo Diablo »</TD></TR><TR><TD CLASS="quote">No knock feedback, and I'm the tuner 
I'll look at the air temp correction.
</TD></TR></TABLE>
Very cool! Yes check the air temp and also coolant temp based corrections. Also there may be a small chance that on the track/road you may be seeing load points that you are not seeing on the dyno (depending on the type of dyno that you are using), again small chance but possible.
I'll look at the air temp correction.
</TD></TR></TABLE>
Very cool! Yes check the air temp and also coolant temp based corrections. Also there may be a small chance that on the track/road you may be seeing load points that you are not seeing on the dyno (depending on the type of dyno that you are using), again small chance but possible.
Honda-Tech Member
iTrader: (2)
Joined: Mar 2002
Posts: 5,828
Likes: 1
From: Woodbridge, NJ, Middlesex
Re: AEM EMS tuning question (El Pollo Diablo)
datalog at track ... and log fuel trims for ait, coolant, boost(map), tps ... compare datalogs as well to dyno if you did log.
greg
greg
Thread
Thread Starter
Forum
Replies
Last Post
