When tuning the VE tables on the L67, every guide I've seen says to make the PE Enable TPS HOT table 100 for all values. Why would you want to do this? I don't understand why you would do this because your AFR would be 14.7 for all kPa except under WOT. Is that not dangerous? Wouldn't you want to tune this table with a wideband and PE enabled?
Last edited by shoafster; 06-13-2009 at 01:19 AM.
you're absolutely right. turning off PE is a leftover myth from days of tuning with narrowbands where all we could measure was stoich. when tuning with WB, there is no point to it. these who change it to 1.00 only demonstrate they follow direction blindly and don't understand how AFR%error get calculated.
Can you explain this alittle more please????Originally Posted by redhardsupra
Darren
2000 GTP M112 GEN V S/C IC Overkill-cam 65lbs INJ 3.4 pulley 1.7 Rockers double roller timing chain
which part?
why is that a myth?? and what problems come from using it this way???
2000 GTP M112 GEN V S/C IC Overkill-cam 65lbs INJ 3.4 pulley 1.7 Rockers double roller timing chain
The myth is tuning VE with a narrowband. You said yourself what the problem is, running 14.7:1 all the time!
2005 Grand Prix GTP
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You can tune the VE or MAF with fuel trims/narrow band sensors but once you enter PE the narrow band data is no good because the fuel trims lock out in PE . So in the old days some would disable PE and so they could tune the whole RPM range. Don't do this though. You don't want to be commanding 14.7:1 at 6000 RPM's WOT. Leave the PE enable where it is as you intend to drive it and accept that you will not be able to tune the upper end of the VE or the MAF without a wide band.
Bill Winters
Former owner/builder/tuner of the FarmVette
Out of the LSx tuning game
ok, thanks guys. Thats what I needed to know.
Thanks Bill makes sense NOW!!
2000 GTP M112 GEN V S/C IC Overkill-cam 65lbs INJ 3.4 pulley 1.7 Rockers double roller timing chain
Trying to tune the VE table on the PCM for the L67 3800Sc engine may be worthless. As far as I know the 3800 engine uses a MAF based system and the VE tables are only used in the event that the MAF malfuctions and the PCM enters the default mode.
It seems that the tuning of the fueling on these engines is best ackomplished by concentating on adjustments to the MAF freq vs flow curve and the PE vs RPM vs Time table. In some cases where an LS1 MAF nad N* TB are used signifcant modifications are necessary.
The VE is also used for example when you blip the trottle.... because the maf will not "see" the airflow quick enough... the PCM use the VE for a split second fot the 'transition' so tuning ve is still important with maf
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