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Thread: Individual Cylinder Trims + Injector Flowsheet?

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Posts: 1-10 of 11
2015-09-09 19:11:25
#1
Individual Cylinder Trims + Injector Flowsheet?
Anyone experimented with the individual cylinder trims, and adjusted them according to a injector flowsheet? Or is there some other use for this table?

Since the flowsheet I have specifies at what duty cycle the injectors are +-0.75%'ish, is it possible to construct a table like this, to get the error down to +-0.25?
2015-09-09 19:34:22
#2
Individual afr, or maybe individual egt would allow you to adjust that table properly. Otherwise you are just taking a shot in the dark.
Last edited by Lynx on 2015-09-09 at 20-00-03.
2015-09-09 19:40:43
#3
I actually have individual egt sensors, but the accuracy isn't reliable imo. Maybe if it was a closed loop system these sensors could be used for cylinder balancing, but that would definately require more ecu processing power...
2015-09-09 19:51:36
#4
I use individual cylinder trims for fuel and ignition on my engine (AEM EMS series 1), and I swear by it.
However, I'm using mine to counter-act the tendency of cylinder 3 to run "hot", and cylinders 2 and 4 to run relatively "normal", and cylinder 1 to run "cool".

I have +4% max extra fuel (based on RPM) for cylinder 3, and a maximum of +2% fuel for cylinders 2 and 4.
I have a max ignition retard of 2.5 degrees (based on RPM) for cylinder 3, and a max retard of 1.5 degrees for cylinders 2 and 4.



Now, your idea of counteracting the small variance of injector flow with individual fuel trims seems like a viable option even without per-cylinder O2 sensors. You could go off the flow chart data you have if it is comprehensive enough. If it were me, I would adjust the trims to balance out the fuel, and then I would adjust the trims on top of that to adjust for the per-cylinder behavior of our engine.

However, if you don't want to get that complex, I would simply do what I've done and ignore trying to balance out the injectors, since they are off by less than 1% each which is less significant than the +4% fuel you should be adding to cylinder 3.
Last edited by BenFenner on 2015-09-10 at 14-05-09.
2015-09-10 02:35:58
#5
Damn Ben sweet response.
I'm about to get 1 of these Ecus so I'll be shouting at u
2015-09-10 05:49:21
#6
@BenFenner Very interesting Ben, mind sharing a screenshot of said configuration?
2015-09-10 11:54:06
#7
I see that I'm actually adding 4% for cylinder 3 and 2% for cylinders 2 and 4.
Looking at these trims, I guess my torque peak is probably somewhere between 4,800 and 5,600 RPM.

Fuel trims (cylinder 2 and 4 are the same):
Last edited by BenFenner on 2015-09-10 at 11-55-26.
2015-09-10 11:55:14
#8
I would only bother doing this if you have a wideband for each cylinder and your tune is SPOT on already to the point where you cannot improve it. In my experience this nets very little power gain and takes a bit of time. If you are a fan of tuning, and a perfectionist - why not! Best of luck.

Walker
2015-09-10 11:57:00
#9
Here are the ignition trims (cylinder 2 and 4 are the same):
2015-09-10 13:18:52
#10
Thanks for sharing this info Ben. I will make changes to my tune accordingly and verify if I can get EGT's closer to each other.

One more thing, does this apply to all SR-engines? DE, DET, VE, VET all the same?
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