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Originally Posted by Built240
I have the programer set to Tow mode and trans seems to shift nicely but im worried about EGT's. Whats the best way to keep them in check?
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Watch your pyrometer, and when it goes over 1,200º pre-turbo EGT, then back out of the go pedal a hair to keep it between 1,200º and 1,250º pre-turbo EGT until you get to the top of the grade.
But you can't do that, because you don't have a pyrometer.
So Rule 1 is to
NEVER use a tune hotter than stock without a pyrometer. So set the Evo back to stock for towing. After you get a pre-turbo pyrometer installed, then you can use the hotter tunes and drive by the gauges.
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About how much can I lay into the throttle without downshifting or kicking it out of OD before EGT's start building?
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You won't have any EGT problem as long as the tranny is in OD. But as soon as it downshifts out of OD, EGT can climb up past the redline in a heartbeat.
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On the flip side.. Anything below 70mph my rpm falls below 2k and engine drags in OD. Is 70+ ok or should I be keeping it out of OD and at 55mph and roughly 2.2k rpm the whole time?
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Running the stock tune, it's going to downshift out of OD way before you hurt anything. So don't worry about it.
The only time you kill the OD is when comin' down the mountain with a trailer pushing on you. Or when climbing a steep grade that will cause the computer to downshift out of OD. If you can see the grade ahead that you know will cause a downshift, then manually downshift as described below before the computer does it for you. And after you downshift, then leave it in direct drive until you get to the top of the pass.
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Also, When I pop it out of overdrive for really long inclines or climbing mountains whats the right way to do this? Should I let off the throttle until it drops the gear or should I keep on throttle?
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With experience, you can judge whether the upcoming grade will cause a downshift out of OD. If it will probably cause a downshift, then I kill the cruise control, slow down to about 55 or 60 MPH, get off the go pedal, then kill the OD. Then reset the cruise at the speed I plan to take the grade. With gauges and my 60-tow tune and grossing 16k, I know mine will stay below 1,250º EGT at 55 MPH up interstate grades, and for some grades I can do 60 MPH without too-high EGT.
But if I didn't have a pyrometer, then I would run stock tune and not climb grades at more than 55 MPH in direct drive.
Ignore the stick shifter folks about "lugging". With an automagic tranny, your engine will never lug. Before the computer allows the engine to lug, it will downshift the tranny - whether you like it or not.
With my 60-tow tune, I can cruise at 1,750 to 1,800 RPM without the tranny automagically downshifting for every little bump in the road. But with a stock tune, I have to cruise at least 1,900 RPM because of the horsepower curve. There's simply not enough horses hooked up below 1,900 RPM with a stock tune when grossing 16k.
