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Discussion Starter · #1 ·
Any reason EGR should be commanded to open 100% as soon as you tip in the throttle? And what speed everyone have there 4th gear shifting in at? for some reason bryan has mine coming in at 64MPH and dropping out at 57 , makes it pretty annoying to drive.
 

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Discussion Starter · #2 ·
well went into tuner cat and dropped it down, but still can't get it below 64..any ideas?
 

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Discussion Starter · #3 ·
35 veiws and no one replies... thanks guys.
 

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Did you ask Bryan?
 

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Discussion Starter · #5 · (Edited)
I got a one time tune, plus the values in the tables are set at the speeds they should be.. I did realize today that i have a rev. B ECM, didn't think to check that before so tomorrow I'll do some adjusting and go from there but right now, its set to shift into 4th at like 45mph at TPS levels lower than 38%
 

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I just realized - what car is this for?
 

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Discussion Starter · #7 ·
read my sig... it will be a few days before I can get back on it due to my surgery. but I think not adjusting the tables in rev b is the problem, but I figured out that its always using the Cruise shift table to shift and not the normal table.
 

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when you re-introduce exhaust gasses into the intake(egr) the unburned hydrocarbons (and the extra heat present, which is more chemically and combustion important) help to act as a packing of sorts, much like in a shotgun shell, to help complete combustion of the fuel at part throttle, because it slows down the flame travel, as the air isn't as turbulent at part throttle as it would be at w.o.t. .(whew! long breath) This is why you disable egr when undergoing tuning and turn it back on for part throttle fuel economy. The extra heat in the egr gasses during colder weather operation help to vaporize the fuel more completely due to the very cold air in the intake tract, and thusly help to reducing chamber carbon buildup from too cold of a combustion cycle.

Remember as air passes the throttle blades it goes from a high pressure area to a lower pressure area and it expands to fill that area as fast as it can so it drops temperature suddenly. An example would be a 35 degree day, with an IAT of 55 degrees, the actual air in the manifold would be 25 degrees or lower in the non boundary layer(fast moving column of air in the airflow stream). This is also the reason for the hot water passage in the throttle body by the way.

Short version, turn egr off while tuning along with canister purge, along with thier respective reporting function code setting parameters, then reintroduce one at a time and complete the tune, ie you may need to change the timing values on your main table if the egr added spark induces pinging. You can even raise the thresholds on the egr so that it only engages at highway speeds of 65 or so, so that if you are going light to light the egr subroutine never engages.

Hope this helps. remember egr is your friend as long as fuel economy at part throttle is a concern.

Chris
 
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