Injector Offset
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Teching In
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Injector Offset So I've been tuning with wideband and have the large part of my VE table settled down, but I'm still chasing a rich condition off throttle. I can come off throttle from a high rpm run and see the smoke trailing behind me.
I'm starting to think it might have something to do with my injector pulsewidth being too high in this area, I'm running the Lucas 42's. Been reading a lot about injector offset and how its hard to find good data, especially for these injectors.
I found out in an older thread on another board that AEM has battery offsets in it's AEMPro product, apparently they have tested various commonly used injectors themselves. I'm not sure if these offsets are specific to the AEM platform or if they could be used either directly or to extrapolate a table for our LSx platform. Anyone know anything about this or have an opinion?
Here's an example table for RC Engineering 440cc (42lb) 16 ohm injectors that is found in AEMPro. I believe RC Engineering uses Lucas injectors.
Offset Table
I'm starting to think it might have something to do with my injector pulsewidth being too high in this area, I'm running the Lucas 42's. Been reading a lot about injector offset and how its hard to find good data, especially for these injectors.
I found out in an older thread on another board that AEM has battery offsets in it's AEMPro product, apparently they have tested various commonly used injectors themselves. I'm not sure if these offsets are specific to the AEM platform or if they could be used either directly or to extrapolate a table for our LSx platform. Anyone know anything about this or have an opinion?
Here's an example table for RC Engineering 440cc (42lb) 16 ohm injectors that is found in AEMPro. I believe RC Engineering uses Lucas injectors.
Offset Table
There is a 2-D table that maps offset time to battery
and manifold vacuum. The trick is, getting a realistic
set of data for it.
Look for a minimum pulse width limit as well, this should
be reduced if you increase injector size. Zero air pretty
much wants zero fuel and the minimum PW, any excess
of offset (mapped) over real offset time, etc. will be a
fuel error.
and manifold vacuum. The trick is, getting a realistic
set of data for it.
Look for a minimum pulse width limit as well, this should
be reduced if you increase injector size. Zero air pretty
much wants zero fuel and the minimum PW, any excess
of offset (mapped) over real offset time, etc. will be a
fuel error.
Thread Starter
Teching In
Joined: Jul 2005
Posts: 19
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That's the table I've been looking at. I was curious if the data for the RC 42's that I found in the AEMPro software (that table I linked to) would be a plausible data set for my Lucas 42's.
I can extrapolate a crude table using the data from AEMPro and the stock table. I suppose if I can just get the pulse width small enough to prevent the rich condition off throttle, then VE tuning with my wideband will sort out the rest.
It just bugs me that I don't have more accurate figures. There are a lot of tables that seem to control these injectors and I hate to just start hacking them up but that seems like the only way to pull the injectors back in line.
I can extrapolate a crude table using the data from AEMPro and the stock table. I suppose if I can just get the pulse width small enough to prevent the rich condition off throttle, then VE tuning with my wideband will sort out the rest.
It just bugs me that I don't have more accurate figures. There are a lot of tables that seem to control these injectors and I hate to just start hacking them up but that seems like the only way to pull the injectors back in line.
Try reducing the injector offset table by 10-12%. I'm sure there are more scientific methods, but this worked for me. Delphi/Lucas injectors react quicker than stockers (or SVOs) and don't require as large of an offset.
